Annual/Termination Reports:

[12/12/2014] [01/15/2015] [01/15/2016] [02/05/2017] [11/27/2017] [01/02/2019]

Report Information

Participants

Loring, Steve (Administrative Advisor) (sloring@nmsu.edu) - NMSU
Nandwani, Dilip (Chair) (dnandwa@tnstate.edu) – Tennessee State University
Prestwich, Clarence (Clarence.prestwich@por.usda.gov) - NRCS, WNSTC
Shukla, Manoj (shuklamk@nmsu.edu) - NMSU
Fares, Ali (alfares@pvamu)- Prairie View A&M University
Porter, Dana (dporter@tamu.edu) - Texas AgriLife Research
Shock, Clinton (Clinton.shock@oregonstate.edu) - Oregon State University
Lamm, Freddie (flamm@ksu.edu) - KSU
Neibling, Howard (hneiblin@uidaho.edu) - University of Idaho
Diaz-Perez, Jaun Carlos (jcdiaz@uga.edu) – University of Georgia
Dumicic, Gvlden (gdumicic@krs.hr) University of Georgia
Bartolo, Michael (michael.bartolo@colostate.edu) – Colorado State University
Roman-Paoli, Elvin (elvin.roman@upr.edu) – University of Puerto Rico
Bordovski, James (j.bordovsky@tamu.edu) Texas A&M University
Lighari, Latif (llighari@tnstate.edu) – Tennessee State University
Jocoby, Pete (jacoby@wsu.edu) – Washington State University
Shackel, Ken (Vice Chair) (kashackel@ucdavis.edu) – UC Davis
Rein, Bradley (brein@nifa.usda.gov) – NIFA
Morgan, Kelly (Secretary)(conserve@ufl.edu) University of Florida

Brief Summary of Minutes

October 22, 2014
Meeting started by Dr. Dilip Nandwani at 8:40 am
Opening remarks by TSU Dean of Extension, Dr. Latif Lighari – Welcomed the group to Nashville and talked about his background as an Ag Engineer in South Dakota with small and large farms with range of irrigation use.
Announcements by Dr. Dilip Nandwani and review of agenda – IA symposium in Nov. 2015 in Long Beach, CA and use of project funds to develop products were new items added.
Discussion of industry participation – Dr. Freddie Lamm – Dr Lamm led a discussion that the group develop a proposal for industry participation in W-3128 meetings. A subcommittee of the W-3128 group was proposed to discuss possible participation by industry. Naming of the subcommittee was tabled to the W-3128 business meeting.
NIFA report by Dr. Steve Loring – Dr. Loring announced to the group that the project has been renewed and the October 2014 meeting constitutes the last meeting of 2128 and first meeting of 3128. He congratulated the group on the Western States Research Directors Award of Excellence, in Reno, NV and national Award for Excellence in Washington in November. He indicated that while W-3128 is a western regional multistate project, it has become a national program because of national scope of irrigation problems. Dr. Loring further indicated that the W-3128 project has great national impact. Dr. Loring suggested that the project must consider a plan to utilize the $15,000 to support for travel to receive awards and products. Recommendations for using the funds were tabled to the business meeting.
Dr. Brad Rein (NIFA rep) He led a discussion on the USDA budget problems and discussed some funding opportunities specifically CARE (Critical Agriculture Research and Extension). Dr. Rein went on to indicate the emphasis of NIFA RFP will be water quality and quantity. It was suggested by Dr. Ken Shackel that a subcommittee be established to work with industry to develop proposals to include a critical need and producer involvement.
Dr. Dana Porter led a discussion on microirrigation design problems with industry reps including lack of proper designs for small projects was conducted. Standards for minimum specifications including uniformity and management were suggested. It was recommended by the group that the Maintenance of Microirrigation Systems web site (winner of ASABE Blue Ribbon award) should be used as a model for products by the group.
State Reports-
Dana Porter & Jim Bordovsky – Texas A&M –The Texas A&M group developed a website on irrigation scheduling using ET/soil moisture balance for multiple fields at multiple farms and the Bushland Reference ET calculator for grass and alfalfa, available as phone app. Research project for furrow, low pressure and center pivot systems to develop technology transfer products for stakeholders to promote adoption of microirrigation, including grower meetings was discussed.
Clarence Prestwich - NRCS – Dr. Prestwich discussed irrigation system criteria and indicated that EU (emission uniformity) increased to 90% as a minimum for new systems and may be increased further. The importance of water quality testing for irrigation design was discussed. It was observed there exists a wide range of tests and costs and that specific tests to base irrigation system design and management should be established. These comments stimulated a good discussion on uniformity and water savings by proper design and water quality testing
Freddie Lamm – Kansas State University – Dr Lamm discussed development of a system to evaluate water quality testing results in Kansas. He suggested a similar system should be developed to evaluate irrigation clogging potential nationally. Discussion by the group indicated that sensors for water quality components should also be evaluated. Conclusion was that standards for agricultural irrigation water samples need to be different than drinking water. The group discussed development of a standard list of tests for agricultural irrigation water that would reduce testing costs to growers.
Lunch
Mike Bartolo – Colorado State University – Dr. Bartolo discussed challenges to adopting drip irrigation in Colorado. He indicated that cost share of equipment and education were the best tools to increase use of drip irrigation. He also indicated that growers have no incentive to conserve water with drip because if you do not use water you lose it (water rights).
Howard Neibling – University of Idaho - Research on nitrate movement with soil depth was discussed. Data indicated that corn silage grown with drip had greater yields and grower acceptance than furrow irrigated corn. Dr. Neibling described the use of cell modem soil moisture loggers and website for irrigation monitoring and scheduling with Washington State University was described.
Kelly Morgan – University of Florida – The use of crop water use models by water management districts in Florida was described. Development and use of smartphone irrigation scheduling apps and irrigation water use and irrigation scheduling research projects on citrus infected by Citrus Greening Disease was summarized.
Ali Fares – Prairie View A&M – The In-situ water monitoring sensor conference in 2014 was described. Water use and conservation research using soil moisture sensors and water quality measurements using suction lysimeters and the effect of soil organic matter on readings of soil moisture was described. It was also determined that addition of sawdust as a substitute for organic matter in sand had effect on the soil moisture measurement of several commonly used sensors.
Manoj Shukla – New Mexico State University – Dr. Shukla described the decline in water table depth from about 10 feet to 25 feet in New Mexico. Research on development of soil moisture sensor calibration, water use, and crop coefficients of greenhouse grown peppers was discussed. A project determining Kc calculated by growing degree day (GDD) was described.
Business Meeting
Dr. Loring, lead a discussion with the objective of suggesting use of projects funds ($10,000) that must be spent by Sept. 31, 2016. A discussion of the group indicated the products funded should include 1) update of irrigation manual, 2) Development of irrigation kits, 3) Website management charges, 4) Landscape water requirement, and/or 5) Sponsor a microirrigation symposium. Dr. Loring suggested that the group should assign a subgroup of 3-4 people to develop alternatives and communicate with the larger group. The group determined that Dr. Freddie Lamm will head the group.
Next meeting location suggestions: Dr. Ken Shackel (next chair) suggested somewhere in California in association with theASABE/ IA symposium in Long Beach, CA scheduled for Nov. 10-12, 2015 so the W3128 would be on Nov. 13, 2015.
Adjourned – 5:30
October 23, 2014 – Field Trip to McMinnville, TN
Mr. Terry Hines, owner of Hale and Hines Nursery gave us a tour of his irrigation control system. The system provides ET and soil moisture sensor based irrigation on field container grown tree production area with fertigation and line treatment. We then toured the Tennessee State research facility and new Ag biotech building, campus farm tour. TSU facilities were toured on our return to Nashville.
October 24, 2014
Meeting opened at 8:30
Business Meeting (con’t)
Submission of State Reports - Dr. Loring led a discussion on State Reports. It was agreed by the group that State Reports be due by November 15, 2014 to the secretary using the same format as last year referencing 2128 objectives with goals for coming year using 3128 objectives.
Subcommittee on project funding (Freddie Lamm, Ken Shackel, Pete Jacoby, and Clint Shock) reported that the W-3128 group should hold symposium, workshop or webinars with invited speakers may be oriented chemistry of emitter plugging.
Review 2013 meeting minutes - Minutes for 2013 meeting were approved.
Election of Secretary - Dr. Pete Jacoby was nominated by Freddie Lamm and second by Ken Shackel. The nominations of approved unanimously.
Clint Shock suggested that the group recognize Dr. Steve Loring for his work to organize the group and complete the paperwork that resulted in 2138 being recognized in the award. The group voted unanimously supported the recognition.
State Report (con’t)
Juan Carlos Diaz-Perez – University of Georgia – Dr. Diaz-Perez described research he conducted on establishing ET of vegetable crops to determine crop ET. He has found that 100% crop is not needed with drip irrigation and the Kcs could be reduced.
Elvin Roman-Paoli – Puerto Rico – Dr. Roman-Paoli described work on ET estimation for fruit, vegetables and root crops using subsurface drip irrigation management and crop rotation. He further described research conducted to reduce leaching of N in citrus and avocado.
Clint Shock – Oregon State University – Dr. Shock conducted studies on E. coli movement in contaminated water in furrow or drip irrigation. Another set of studies looked at N rates in soil solution determining that if soil solution is used to schedule N applications less N is used with similar yields compared to predetermined fertilizer schedules.
Dilip Nandwani – Tennessee State University – Dr. Nandwani reported work in Virgin Islands on collection of rainwater for irrigation in reservoirs. He also conducted a study using a water collection kit for drip irrigation using manual pump from a surface rainwater reservoirs. While at TSU, he has established certified organic plots and has produced sweet potato on three types of mulches.
Meeting was adjourned at 11:20

Accomplishments

Objective 1. Compare irrigation scheduling technologies and develop grower-appropriate scheduling products <br /> <br /> (CA) Irrigation levels from about 70 to 110 % ETc were imposed on test plots in commercial almond orchards in 3 locations across the central valley of CA in order to develop an almond water production function. Tree water stress (SWP) as well as soil moisture was monitored on an approximately weekly basis from March to October, and other important variables (canopy PAR interception, yield) were recorded. Based on previous studies we did not expect to see a substantial reduction in yield, PAR, or yield/PAR, and only one site showed a statistically significant reduction (15 %) in yield for the lowest irrigation level (70% ET) compared to the control (100% ET). This is the first year that differential irrigation levels have been imposed at these sites, and since many important effects of water stress are carryover effects, only tentative conclusions can be reached. All sites showed a clear increase in stress with reduced irrigation, but even when provided with excess water (110 to 116% of calculated ETc, depending on site) no site exhibited baseline (non-stressed) values of SWP throughout the season. Interestingly, two sites (Kern and Merced counties) showed generally lower SWP values compared to the third site (Tehama county), but had generally higher yields, and all yields were strongly related to crop load. This may be an early indication that under some conditions water stress may have a beneficial effect on almond yields. A mobile sensor suite was developed and evaluated to predict plant water status by measuring the leaf temperature and microclimatic variables in nut crop trees and grape vines. The sensor suite consists of an infrared thermometer to measure leaf temperature along with other relevant sensors to measure microclimatic variables. The sensor suite was successfully evaluated in commercial orchards in central valley of California on three or<br /> (ID) A web-based water-budget irrigation scheduling program developed by Dr. Troy Peters, WSU, and a soil sensor based approach with web-based data availability were compared on 6 barley fields in eastern Idaho in 2014. The WSU “Irrigation Scheduler Remote” program used irrigator-selected soil and crop parameters, AgriMet daily estimated crop ET, and rainfall, and irrigator-input irrigation data to evaluate root zone available soil water and depth of irrigation water required to re-fill the root zone on a daily basis. <br /> (ID) Watermark sensors were installed at 4 depths (12, 18, 24 and 30 inches) on each field to serve as a daily comparison measurement. Data from the sensors and a tipping bucket rain gage were transmitted by cell phone link to a website at 30-minute intervals. This information, formatted in a user-defined fashion, was available from any mobile device (cell phone, laptop, desktop,...) that could connect with the website. Pre and post-season soil sampling at 6-inch intervals to 5 feet (or rock) depth along with rain gage data provided directly-measured water budget information. <br /> (OR) Previously we determined the ideal soil water tension irrigation criteria for the onset of irrigation for drip-irrigated onion. The results were based on assumptions of the ideal plant population to optimize the economic return for onions given US market opportunities. Worldwide onions are often planted at greater plant populations for market opportunities to sell smaller diameter bulbs. Replicated trials indicate that the ideal irrigation criteria for smaller sized onions is drier and less sensitive to very wet irrigation criteria than yield and income optimization for the US market.<br /> (OR) Native wildflower seed is needed to restore rangelands of the Intermountain West. Commercial seed production is necessary to provide the quantity of seed needed for restoration efforts but a scientific basis of seed production is lacking for thee species. A major limitation to economically viable commercial of native wildflower seed production is stable and consistent seed productivity over years. <br /> In native rangelands, the natural variations in spring rainfall and soil moisture result in highly unpredictable water stress at flowering, seed set, and seed development, which for other seed crops is known to compromise seed yield and quality. <br /> By burying drip tapes at 12-inch depth and avoiding wetting the soil surface, we hoped to assure flowering and seed set without undue encouragement of weeds or opportunistic diseases. Irrigation and plant establishment results are now available for over 20 species through this work.<br /> (OR) Real time knowledge of soil moisture is helpful to assure crop yields and reduce negative off site effects of irrigation. Manual data retrieval from each field is time consuming and wiring complicates mechanical farming practices. The combined use of soil moisture sensors, a wireless sensor web, and internet communication, could allow growers to view soil moisture data, sensor diagnostics, and other useful information from a computer, smartphone, or tablet. We tested a IRROmesh™ system that used a SensMitWeb™ smartmesh radio platform. The system read soil temperature and soil water tension using three Watermark™ soil moisture sensors in each of twelve fields planted to eight different crops. Real time soil data and graphs of soil water tension trends were easily accessible by smart phone. These preliminary trials using the sensor web showed that this technology holds potential for saving time, increasing accuracy of irrigation scheduling, and assuring yield. <br /> <br /> (TX) The Texas High Plains ET (TXHPET) Network continued to provide free public access to ET-based crop water demand information (using the ASCE-EWRI Standardized Reference ET model) through the Texas A&M AgriLife Research and Extension Water Management Website (watermgmt.tamu.edu). The TXHPET Network also continued to support research programs with access to their secure database. <br /> <br /> The Bushland Reference ET Calculator, developed by a team led by Dr. Prasanna Gowda (USDA-ARS-Conservation and Production Laboratory) is now available through the Laboratory website (http://www.cprl.ars.usda.gov/swmru-software-bretc.php) and through the Apple App store. Improvements include broader geographic applicability. <br /> <br /> The Texas High Plains Water Management Soil Moisture User Profile Tool, available through the Water Management website, is being used in combination with Sentek EnviroSCAN soil moisture probes to manage irrigation treatments in a study comparing subsurface drip irrigation, low pressure center pivot irrigation and furrow irrigation of corn. The Soil Moisture Profile Tool applies ET-based crop water demand and soil moisture balance models to inform in-season irrigation scheduling decisions. Thomas Marek (Senior Research Engineer, Texas A&M AgriLife Research – Amarillo/Bushland) and Dana Porter are co-principal investigators in this work. <br /> <br /> (FL) Web-based tools that were previously developed had little user-tool interaction and depending largely on the user remembering to return to the website and engage. Smartphone apps provide a different level of engagement with users. Apps allow for notifications and ease of accessibility. The growing use of smartphones and accessibility to weather data has resulted in an ideal situation for implementing smartphone apps for irrigation scheduling. Thus, study objectives were to (1) develop smartphone apps for scheduling irrigation using real-time and forecasted meteorological data and (2) provide users with an irrigation schedule for specific crops developmental phenology based on their site soil and irrigation system characteristics and weather conditions. Field evaluation is encouraging with good user input with suggestions to improve interfaces and outputs. <br /> <br /> Additional studies have been conducted to improve our understanding of citrus water use by infected with Huanglongbing (HLB) (Candidatus Liberibacter asiaticus). Soil moisture distribution in infected and affected groves is critical for devising appropriate recommendations for optimizing water use and sustaining citrus yields. Thus, the studies described in this report are being conducted to investigate water use patterns and soil moisture movement within groves in central, south-central and southwest Florida. Treatments being evaluated include: 1) daily irrigation (Daily), 2) Institute of Food and Agricultural Sciences (IFAS) recommended scheduling, and 3) irrigation scheduled half the number of days between irrigation recommended by IFAS (Intermediate). The irrigation amounts of the daily and intermediate irrigation schedule are reduced at each irrigation event but provided similar amounts of water to the IFAS recommendation over long periods of time. Preliminary results indicate that water use per unit leaf area ranged from 0.09 to 0.10 oz/ inch2/day at all sites depending on irrigation schedule. Moisture contents were similar among irrigation schedules varying between 5 to 20%, 1 to 14% and 5 to 25% at 6-, 12-, and 18-inch soil depths, respectively. Soil moisture contents increased with depth possibly as a result of uptake in the top 12 inches. These preliminary findings should help in refining limits for available water contents and estimating irrigation demand estimations to sustain citrus productivity of HLB infected trees. Annual water use data were not statistically different among irrigation treatments at any site and were consistent with the goal of this study in that the same amount of water be used for all treatments. Yield data collected in December 2013 indicate that six months (including the rainy season) of the three treatments did not affect yields in the first year of the study.<br /> <br /> <br /> <br /> Objective 2. Develop design, management and maintenance recommendations <br /> (KS) An oral presentation with written paper entitled “Successful SDI - Addressing the essential issues” was given at several events, regional meetings in Oregon and Colorado, an international conference in Argentina and as a seminar to the Irrigation Association’s technical conference.<br /> <br /> (KS) The microirrigation maintenance website developed by University of California-Davis, Kansas State University, and Texas A&M University was selected for a ASABE Blue Ribbon award as an education aid in the website category.<br /> <br /> (KS) Joint technology transfer efforts concerning SDI involving Kansas State University, Texas AgriLife and USDA-ARS were continued in 2014. These efforts included presentations at local, regional and national meetings.<br /> <br /> (ID) A subsurface drip irrigation (SDI) system was installed in a center pivot corner in May, 2012 using support from a USDA-NRCS Conservation Innovation Grant to determine the suitability of SDI for corn silage production under Idaho soil, climate, and harvest conditions. Three drip tape depths (6, 9, and 12 inches) and 2 tape spacings (30 and 44 inches) were installed. In 2014 corn for silage was planted on Reps 2 and 3 of the trial. Rep 1 was abandoned due to excessive rodent damage. The un-mowed grass and weeds in the fence line and adjacent canal area appeared to provide better habitat for rodents, resulting in greater damage on Rep 1. At harvest, corn ear weight (highly correlated with total crop tonnage and feed value) was measured from all 12 Rep 2 and 3 plots. System performance and crop yield and quality will be measured for a surface drip tape placement in 2015. This site will serve as a demonstration site for this technology, with a field day in June 2015.<br /> (TX) Jim Bordovsky and his research team at the Texas A&M AgriLife Research Center at Halfway, Texas, have completed a multi-year study of the effects of varying irrigation capacities on cotton production in the Texas Southern High Plains. In addition to varying irrigation capacities (deficit to full irrigation), Bordovsky’s team has evaluated effects of the timing of irrigation capacity deficits, and the relative responses of the crop to water during different crop growth stages. This work will provide essential knowledge for in-season cotton irrigation recommendations that optimize water value and lint yield in an area with declining irrigation capacity and increasing pumping restrictions.<br /> <br /> <br /> <br /> Objective 3. Develop best management practices for application of agrochemicals <br /> (KS) A poster presentation related to conjunctive use of water and nitrogen with subsurface drip irrigation for corn production was presented at a field day at Colby, Kansas in August.<br /> <br /> (KS) Oral presentations of related to conjunctive use of water and nitrogen with subsurface drip irrigation for corn production were made at a regional meeting in Oregon, at the American Society of Biological and Agricultural Engineers (ASABE) in Montreal, Canada, and at international conferences in China and Argentina. <br /> <br /> (NM) We continued to work with the compensated root water uptake using partial rootzone drying (PRD) techniques. The experiments were conducted using chile plants (NuMex Joe Parker; Capsicum annuum). Results supported our previous observations that chile plants were able to take up more water from less water stressed part of the soil profile while maintaining the plant stress (stem water potential) similar to that in control treatment. Water balance analysis showed that PRD techniques reduced the deep percolation and required the irrigation amounts to 30% less than control.<br /> <br /> (OR) Improved P and K fertilization of drip-irrigated onion could help to assure yields while using lower levels of inputs. Six different P and K applications strategies are being compared in replicated plots based on information collected by soil analysis, plant tissue analysis, and soil solution sampling.<br /> <br /> (OR) Weeds like yellow nutsedge are exceedingly difficult to control in onion. Initial work is exploring rates and timings of applying Outlook through drip irrigation for yellow nutsedge control. This method of application is not currently labeled.<br /> <br /> (OR) Several soil borne diseases attack onion. Preliminary studies are being conducted to examine options to manage these diseases via the application of fungicides through the drip irrigation system. These application methods are not yet labeled.<br /> <br /> (VI and TN) U.S. Virgin Islands have high rainfall but little irrigation water for farming available for growers. A study conducted using a low pressure irrigation system at the University field on St. Croix. Irrigation kit designed by Proximity Drip Irrigation, CA, containing overhead water collection tank (250gallon) for drip irrigation using a manual pump from a surface rainwater reservoir installed. The system applied to irrigate leafy greens in summer 2013. Quality yields in crops (spinach, bok choy, kale and lettuce) obtained. Data are under analysis. At Tennessee State University, a variety trial on organic sweet potato conducted using drip irrigation and quality yield obtained in three cultivars in various mulches. <br /> <br /> (TX) The Irrigation for Small Farms manual is in revision, and it will serve as the foundation and primary reference for a series of online presentations (webinars or shortcourses). Work also has been initiated to update and revise the Irrigation Training Program materials. <br /> <br /> Electronic delivery (via websites) is the primary venue for delivery of these materials to the public. They also provide ready access to materials for sharing among research and outreach programs. The Texas A&M AgriLife Research and Extension Texas High Plains Water Management Website (watermgmt.tamu.edu) provides access to educational materials, research summaries, and other information. Since cotton is the crop most widely irrigated with microirrigation in Texas, cotton-relevant microirrigation research reports and summaries, white papers and Extension fact sheets are available on the Texas A&M AgriLife Extension Service Cotton website (cotton.tamu.edu). Texas Southern High Plains microirrigation research reports are available on the Texas A&M AgriLife Research and Extension Center at Lubbock webpage (Lubbock.tamu.edu). Irrigation scheduling software and research manuscripts are available on the USDA-ARS Conservation and Production Laboratory (Bushland, Texas) website (http://www.cprl.ars.usda.gov/swmru-publications.php). Research and extension presentations, project reports and other information are available on the USDA-ARS Ogallala Aquifer Program website (http://www.ogallala.ars.usda.gov/); Ogallala Aquifer Program projects include research and technology transfer collaborations among faculty and scientists at USDA-ARS-Conservation and Production Laboratory, Kansas State University and Texas A&M AgriLife Research and Extension. <br /> <br /> Microirrigation research updates and management recommendations are presented in a variety of “face-to-face” venues, including traditional Extension “CEU” meetings for agricultural producers, Master Gardeners, and other end-users. Examples of irrigation workshops and presentations are listed in the Educational Activities section below. Five professional development events (in person and webinars) were conducted for County Extension faculty, with emphasis on the Texas High Plains, Rolling Plains and West Texas where there is most producer interest in microirrigation (especially subsurface drip irrigation). Jim Bordovsky and Dana Porter presented several invited presentations for Regional Water Planning Groups, Groundwater Conservation Districts, Water Conservation Symposia, Commodity Groups, Trade Associations, and International Corporations (Netafim, Bayer, etc.). Examples of these technology transfer activities are listed below. <br /> <br /> (FL) An experiment to determine differences, if any, in water uptake among infected and non-infected trees is being conducted. Young trees ~3 years old were planted in lysimeters filled with Immokalee fine sand collected from the top 0 to 30 cm of a field at the Southwest Florida Research and Education Center (SWFREC). Twelve Valencia (6 HLB positive and 6 HLB negative) and 12 Hamlin (6 HLB positive and 6 HLB negative) trees were used. The study uses the CR1000 program for monitoring changes in water use using weighing scales and monitoring soil moisture every 30 minutes. The water use was assumed to be the loss in weight between 10:00 am the previous day (maximum lysimeter weight following irrigation) and the weight at 7:30 am the following day (minimum lysimeter weight before next irrigation event is triggered) (Fig. 1). Soil moisture is measured every 30 minutes using TDR probes connected to the same data logger used to collect lysimeter weights. A weather station has been installed to collect weather data for estimating reference evapotranspiration (ETo) and temperature and relative humidity changes in the greenhouse. Stem water potential was measured using a pressure chamber (Model 125 1000, PMS Instrument Co., Corvallis, OR). Consistent readings for the program have been recorded from January 2014. Leaf area index of the trees were collected twice yearly using a Sun Scan LAI meter (Dynamax, Inc.) that measures light transmission through the canopy compared with light reaching the ground away from the tree canopy. The goals of the study are to 1) compare water use between Hamlin and Valencia oranges under greenhouse conditions, and 2) compare water use between HLB positive and HLB negative trees.<br /> Preliminary results for trees of similar sizes show similar water use and stem water potential between Valencia and Hamlin and Huanglongbing infected vs non-infected trees, and moisture contents slightly at or above field capacity between 10 and 17% volumetric water content for the period. Leaf area index is a direct measure of canopy density. The canopy had recovered in January and initial LAI measurements were taken, with no significant difference in mean LAI for Hamlin trees compared with Valencia and HLD infected compared with non-infected trees. Data collection continues including monitoring daily water use, soil moisture measurement every 30 minutes and measurement of stem water potential and leaf area index three times a year.<br /> <br /> <br /> Objective 4. Evaluate use of non-potable water through microirrigation <br /> (KS) A poster presentation entitled “Application of Biological Effluent with SDI” was given at an SDI Technology Field Day, Colby, Kansas in August.<br /> <br /> (NM) Salinity responses and salinity-related suppression of budbreak of drip irrigated pecan [Carya illinoinensis (Wangenh.) K. Koch] seedlings under different irrigation water salinity levels were investigated in the pot-in-pot system. No pecan seedlings under the irrigation treatment levels of 5.5 and 7.5 dS/m survived to the end of the 2-year growing period. Paper was published in HortSci.<br /> <br /> (OR) The FDA has drafted new fresh produce rules due in part to the contamination of fresh water with microorganisms that could spread human diseases. We examined drip vs. furrow irrigation in the movement of soil water carrying E. coli to the base of a vegetable crop using onion as a model.<br /> <br /> Surface irrigation systems reusing water can deliver bacteria to produce destined for fresh consumption. We tested furrow irrigation using canal water with moderate or high levels of E. coli contamination and drip irrigation using canal water and well water free of E. coli. The four irrigation systems (replicated five times) applied water to onion on silt loam. Water was sampled hourly for E. coli and the lateral movement of E. coli in the soil solution was tracked by soil samples and Sterile Soil Solution Samplers at the end of irrigations. Onions were sampled for E. coli contamination. The most probable numbers of E. coli in water and soil water were determined using IDEXX Colilert® and Colisure®, respectively, +Quanti-Tray/2000®. Furrow irrigation delivered E. coli to the soil immediately adjacent to the onion bulbs. E. coli movement under drip irrigation was mostly confined to near the drip tape.<br /> <br /> (OR) The delivery of bacteria through irrigation water could contaminate produce destined for fresh consumption. We tested chlorine dioxide at 1 and 3 ppm through drip irrigation to reduce generic E. coli in water delivered to a commercial onion field. Generic E. coli is used as an indicator species for fecal contamination in water. The most probable number of E. coli in water samples was determined using IDEXX Colilert® +Quanti-Tray/2000®. An AgriSystem 2.3 (CH2O, Olympia, WA) utilizing two metering pumps (Model EWC21Y1VC, Walchem, Holliston, MA) mixed 15% sulfuric acid plus additives (Sure Flow F, CH2O) and 15% sodium chloride plus additives (Clean Finish, CH2O) at a 1:1 ratio before the sand media filter station to generate chlorine dioxide. Water was sampled for E. coli at its canal source, after the filter station, and progressively across the field. Chlorine dioxide substantially reduced E. coli counts at all sampled locations and concentrations.

Publications

Impact Statements

1. The plant-based method of midday ?stem water potential? (SWP), measured using the pressure chamber, has become a widely accepted method to ?fine tune? irrigation management in many tree crops. The term first appeared in the scientific literature in 1970, but until 1992, when it was developed as a reliable measure of plant water stress, only appeared in an average of about 1 paper/year. After 1992 there has been a steady increase in the rate of papers using this term, reaching over 50 papers/year in 2013. Information developed using this tool has been a critical component of our current recommendations for dealing with the drought in California orchard crops.
2. Presentations of SDI research results reached approximately 700 participants in various venues potentially impacting irrigation management on a large land area in the Central Great Plains and beyond. Adoption and successful use of subsurface drip irrigation systems is being enhanced by extensive and robust technology transfer efforts in the Ogallala region.
3. The partial rootzone drying technique has the potential to be adopted as water saving technique in chile production system in arid regions such as New Mexico. The bud break in Pecan roots, development and survival of young Pecan trees is sensitive to the soil salinity.
4. Although project personnel worked closely with growers to help establish initial soil and crop information for the program, lack of in-season grower willingness to input irrigation data limited the usefulness of the water budget approach. Growers were interested in the data provided by the soil moisture sensors, appreciated the ease of data access, and did use it somewhat. Because the systems are relatively expensive, the level of grower adoption is uncertain.
5. When actual soils, crop and irrigation information was entered into the WSU scheduler, results (indicating when and how much the grower should irrigate, and amount of deep percolation loss) compared well with the soil sensor method. Because the WSU scheduler is free for grower use, development of a method to integrate actual irrigation information into the scheduler should significantly increase the level of grower adoption, and result in better utilization of limited irrigation water.
6. If SDI can be shown to be a cost-effective irrigation system for corn production on center pivot corners, it will provide additional conveniently-located acres to help meet demand for corn silage while minimizing labor, energy use, and water use on the SDI area. It will also protect surface and ground water as well or better than any other irrigation system.
7. Irrigation scheduling by soil water tension allows growers to use water more precisely. Calibration of soil moisture instruments promotes improved irrigation scheduling with greater precision and confidence. Crop yields have increased and water is being conserved. Fertilizer used on onions has declined. Groundwater nitrate contamination has been decreasing continually over the last decade.
8. Better use of irrigation systems and irrigation criteria for onions are increasing onion yields and reducing environmental consequences of onion irrigation. Drip irrigation is used locally on over 50 percent of the acres and accounts for over 50 percent of the local production. Combining drip irrigation with careful irrigation scheduling reduces the negative environmental consequences of onion production: water and nutrient applications are very close to the actual needs of onion and nitrate does not leach to groundwater. Nitrogen application rate to drip-irrigated onion has decreased by half as yields have increased. Groundwater water quality is improving in Oregon over the entire onion production region of the Treasure Valley.
9. Effective integrated (multidisciplinary, multi-agency) collaborations; geographically and commercially relevant applied irrigation research programs; cost-share and low interest loan programs; accessibility of irrigation components and experienced irrigation designers and dealers; and excellent cooperation among Land Grant faculty, irrigation industry, and agricultural producers are recognized as major contributing factors toward the relatively high rate of adoption of subsurface drip irrigation in the Texas High Plains, Rolling Plains and West Texas.
10. USDA-ARS, Bushland, Texas conducted a second year of cotton production under minimum-tillage, where mid-elevation spray, low elevation spray, LEPA, and SDI were compared in one experiment, and different SDI designs were compared in another experiment. Both experiments included a range of irrigation rates (near-dryland to full irrigation). Results from 2013 were inconclusive because the crop sustained high wind damage just prior to obtaining hand samples. Results of 2014 are not yet in, although lint yield from the spray-LEPA-SDI experiment were obviously much greater than those from the SDI design experiment, where the latter sustained substantial hail damage during early June 2014. A cotton planting date study was conducted in 2014 under SDI with full irrigation where six different planting dates were compared, but these resulted in very little lint yield regardless of planting date.

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Report Information

Participants

Brief Summary of Minutes

Accomplishments

Publications

Impact Statements

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Report Information

Participants

Brad Rein, USDA-NIFA, brein@nifa.usda.gov
Rhucinito Ferrareri, Univ. Virgin Islands, ferrareri@uvi.edu
Elin Roman Paoli, Univ. Puerto Rico, elin.roman@upn.edu
Joel Schneekloth, Colorado State Univ., Joel.Schneekloth@colostate.edu
Claude Corcos, Toro Corp., Claude.corcos@toro.com
Suat Irnak, Univ. Nebraska, sirmak2@unl.edu
Samia Amiri, Oklahoma State Univ., Samia.Amiri@okstate.edu
Saleh Taghvacian, Oklahoma State Univ., salek.taghvacian@okstate.edu
Jiri Simunek, UC-Riverside, JIRI.SIMUNEK@UCR.EDU
Clint Shock, Oregon State Univ., clinton.shock@oregonstate.edu
Jim Bordovsky , Texas A&M Univ., j.bordovsky@tamu.edu
Tsaya Kisckka , Kansas State Univ., ikissekka@ksu.edu
Delan Zha, China, dlzhu@izl.edu
Freddie Lamm , Kansas State Univ., flamm@ksu.edu
Ken Shackel, UC-Davis, kashackel@ucdavis.edu
Maluneh Yitayew, Univ. Arizona, myitayew@email.arizona.edu
Pete Jacoby, Washington State Univ., jacoby@wsu.edu

Brief Summary of Minutes

Nov. 12 (13:00 – 17:00):

Ken Shackel – 2015 Committee Chair, presiding

(Kelly Morgan – 2015 Vice Chair, only present on Nov. 13)

Pete Jacoby – 2015 Secretary, recording

Registration, Introductions

Agenda review and changes to agenda

• No changes

 

Business meeting

• 2016 meeting location be determined by the 2016 Committee Chair (Kelly Morgan)

1. Possible meeting locations could be Florida, Virgin Islands, or Phoenix (at end of ASA,CSSA,SSSA meeting during first week of November)

• Secretary (Johnny Ferrarezi) – elected with term beginning at 2016 meeting


• Webinar – clogging and remediation of micro-irrigation systems

1. Beta test with a small group


2. Prepare and present archival webinar


3. W3128 group should submit ideas for subject matter


4. Money needs to be spent - $13.4 k – ($10 k for webinar and $3.4 k for tour at next meeting) - Ken will check with Steve Lohring about using the residual funds for the tour at the next meeting after the webinar costs are covered

Overview of W3128 multi-state project (Brad Rein – USDA NIFA)

• Experiment Station directors approve new projects (over 200 multi-state projects currently)


• Report is usually submitted for each project by each state Experiment Station director


• Focus on objectives – listed on back of meeting agenda

 

Updates from NIFA (Brad Rein)

• Operating on continuing resolution (cannot obligate funds, except 1^st quarter)


• 2016 AFRI – has provision to consider priorities established by commodity boards that align with those of NIFA


• Water for Agriculture – RFA

 

Shortage of Water (Irrigation) Engineering Faculty positions (Brad Rein)

• Meeting between Sonny Ramaswamy and Ag. Engineering Dept. Chairs from Land Grant universities to discuss situation


• AFRI funding is phased to assist new faculty applications (considered “new” if faculty member has not received a grant from AFRI)

 

State Project Updates and visitor reports (Nov 12 and 13)

 

A number of attendees presented a state project update by PowerPoint or oral update on research and education activities being performed to advance use of subsurface micro-irrigation for better water conservation and crop production. On Thursday afternoon, Freddie Lamb (KS) summarized findings from a recent review of 150 published works on SDI. Seleh Taghvaeian (OK) discussed work on more effective irrigation scheduling using the OK MesoNet and HYDRUS 2D/3D modeling. Jim Bordovsky (TX) reviewed his work on SDI on cotton production in the southern high plains near Lubbock. Zhu Delan presented her work on use of porous ceramic emitters in China. Jiri Simunek discussed irrigation applications of HYDRUS. On Friday, state presentations continued, led off by a presentation by Freddie Lamm on corn production with SDI. Kelly Morgan (FL) briefed the attendees about impacts of HLB (greening disease) on the Florida citrus industry. Suat Irmak (NE) discussed the development and studies associated with a comprehensive field scale site to perform research on use of SDI on a variety of crops. Pete Jacoby (WA) discussed use of SDI delivered through hard PVC delivery tubes in vineyards. Claude Corcos (TORO) brought an industry perspective to the group, indicating that 5 million acres are under SDI and a number of crops respond very favorably to SDI. Problems with gopher damage and emitter clogging continue to plague some users, so both education and training are important factors in maintaining and designing systems. System design issues address on-farm efficiency and basic hydrology. Elin Roman Paoh discussed the use of low-pressure bubblers in Egypt. Clint Shock (OR) updated the group on SDI for production of steevia and issues of nutrient balance and scheduling in wheat. Johnny Ferrarezi (VI) reported on his research using the Arduino micro-controller with sensors. Paul Colaizzi discussed issues of overwatering based on certain crop coefficients and reduction of evaporation with SDI. Ken Shackel (CA) discussed use of stem water potential as a baseline by which to schedule irrigation.

 

 

Webinar Discussion

 

Ken Shackel led a group discussion about the educational webinar to be conducted prior to the 2016 meeting. It is envisioned to be preceded by a “dry run” to help refine the programmatic content. Comments from the group included the following considerations:

• Real life examples


• Non proprietary


• Geographical representation – different areas have different problems


• Focused central topics


• Types of plugging (internal and external)


• Filtration – both for particulates and biotic material


• Water quality issues


• Preliminary considerations prior to purchase and installation of a system, including maintenance


• Placement of injector in relation to filtration system – issues of back-flushing chemicals


• Utilize Grange network


• Develop the product, then consider the marketing

W3128 Objectives

1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.
   
   
   
   1. Development and Evaluation of Soil-Based Irrigation Scheduling
   
   
   2. Development and Evaluation of Weather-Based Irrigation Scheduling
   
   
   3. Development and Evaluation of Plant-Based Irrigation Scheduling
   
   
   4. Software Development and Comparison of Multiple or Combined Irrigation Scheduling Methods
   
   
   
   


2. Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.
   
   
   
   1. Improved Management for Soil Salinity and Source Water Quality Concerns
   
   
   2. Improved Efficiency of Water and Nutrients
   
   
   3. Improved Designs and Performance of Microirrigation Systems
   
   
   
   


3. Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.
   
   
   
   1. Development and expansion of internet-based resources, decision tools and applications
   
   
   2. Development of print and multimedia content
   
   
   3. Coordination of Educational Events
   
   
   4. Advancement and Promotion of Microirrigation through Public-Private Partnerships
   
   
   
   

Milestones (2015):

Laboratory and field studies to select, develop, calibrate, adapt, and evaluate soil water sensors begin.

Software development/adaptation/modification and field studies involving weather-based irrigation scheduling begin.

Plant-based sensor development/modification and their evaluation in field studies begin.

Field studies to evaluate single, multiple, or combined irrigation scheduling techniques begins.

Modeling, field, and educational efforts to address soil salinity and poor source water quality begin.

Field studies will be initiated to determine optimal DI and SDI water and nutrient management for various crops.

Initial discussions and outlines will be developed for both publications and software being jointly developed or adapted to a new locale.

Tours, field days and educational events will be held at the local and regional level to promote microirrigation.

Outline of needs for small holder systems will be developed in cooperation with USDA-NRCS.

Conduct roundtable discussions with industry partners to identify needs and possible areas of cooperation.

Initiate a pilot joint activity with industry to gage opportunities and challenges of such activities.

Accomplishments

<ol><br /> <li><strong>Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</strong></li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>(AL)</strong> Continued using replicated SDI fertigation plots (cotton) in northern Alabama with capability to manually adjust timing of nutrient injection throughout the season. Eight years of subsurface drip irrigation with corresponding cotton yield and daily weather data collection has been completed with replicated research plot study. Results currently being compiled for publication with Biosystems Engineering graduate student.</p><br /> <p><strong>(AZ)</strong> Field data that was collected for two seasons at the University of Arizona&rsquo;s Campus Agricultural Center in Tucson, AZ, was analyzed to determine heat-unit based crop evapotranspiration (ETc) for field corn. The volume balance approach was used to determine the actual crop evapotranspiration.&nbsp;&nbsp; The reference evapotranspiration (ET0) that was used to determine the crop coefficient was taken from the Arizona Meteorological Network (AZMET). The resulting crop coefficient was plotted as a function of the heat unit i.e., growing degree days for the period the crop coefficient was developed. The result fit very well with crop coefficient developed by other researchers. In Tucson, Arizona, USA, two planting dates, May 5th and June 15^th and four sweet sorghum varieties (M81E, ST, SM and A4) were evaluated to estimate crop coefficients (kc) based on the heat unit accumulation concept (GDD). One irrigation level at 50% depletion of available water capacity prior to irrigation and its effect on juice, biomass and ethanol yields was evaluated. Results show that it was possible to develop heat unit based kc&acute;s for two day-neutral varieties (ST and SM) and that they required 25% less water than the photo-sensitive varieties. Peak crop coefficients were determined as 1.13, 1.05, 1.16 and 1.22 for M81E, ST, SM and A4. Results also showed that Growing Degree Days accumulated to flowering were 2226 and 1759 GDD for ST and SM respectively. At a P-value of 5% there were differences in crop water use, juice yields and bagasse production among treatments. For the May planting there was a slight effect on ethanol yields but no effect for the June planting showing that regardless of the planting date and variety they are more likely to be similar.</p><br /> <p><strong>(CA)</strong> An alternative tensiometer design was developed that eliminates temperature-induced diurnal tensiometer fluctuations and removes the limitation of depth of installation. The new tensiometer is especially suited for deep soil monitoring of soil water potential gradients as required for water and nutrient leaching in irrigated systems.&nbsp;&nbsp; A dual-probe heat pulse sensor (DPHP) was developed for improved soil moisture measurements, and exhibited a root mean square error of 1.4 % volumetric water content. The DPHP method is largely advantageous of other available soil moisture measurements, is generally soil-independent, and is especially suitable for field soil water content monitoring because of its robust design with rigid probes. Because of its simplicity and measurements being independent of soil type, we propose the presented DPHP method as an excellent alternative to other available measurement techniques for soil water content. The plant-based technique of midday stem water potential (SWP) was used in a number of industry funded irrigation scheduling projects in commercial walnut and almond orchards. In walnuts, the start of irrigation in the spring was delayed compared to the grower practice until a threshold SWP was reached (1, 2, 3, or 4 bars below baseline). In 2014, grower practice corresponded to the 1 bar treatment, but for the rest of the treatments a substantial delay of 4 to 7 weeks (depending on the block and threshold) was possible, and allowed a water savings of 15-30%, with a 10% reduction in yield only for the highest (4 bar) threshold but no effect on nut quality. The 2 bar treatment had a minimal effect on yield and nut size, but allowed a substantial delay in the start of irrigation and may result in improved tree health in the long term. Novel plant-based measures of stress (in-situ psychrometry, dendrometry, sap flow) are being tested on walnuts in the greenhouse. In almonds, yield, applied water, and SWP are being measured for a range of irrigation amounts at each of three sites. The reduction in crop yield for a 40% difference in orchard water use (applied + soil water used), ranged from 0 to 40% depending on the site. The site with the highest yields was not the site with the highest water application, indicating that the water production function may depend on site effects. A lysimeter was planted to almonds in order to determine the level of stress required to reduce orchard transpiration.</p><br /> <p><strong>(FL)</strong> Citrus greening or Huanglongbing (HLB) is the most fatal and epidemic citrus disease caused by <em>Candidatus</em> Liberibacter, and there is an urgent need for strategies to sustain production of citrus trees affected by HLB without depletion to our resources including water. Understanding the role of evapotranspiration (ET) in HLB affected trees is critical for determining if changes in water management of commercial citrus orchards are necessary. A study was initiated in March, 2013 on five-year-old sweet orange (Citrus x sinensis (L.) Osbeck) trees located in three commercial groves at Avon Park on the central Florida ridge; and near Arcadia, and Immokalee in flatwood soils in southwest Florida. Each grove had three irrigation regimes including daily, IFAS (Institute of Food and Agricultural Sciences) recommendation and intermediate irrigation schedules. All groves received approximately the same volume of water per week based on evapotranspiration. Sap flow measurements were taken three times per year on three trees per treatment with three sensors per tree. Volumetric soil water content (VWC) was measured continually using data logger EM 50 (Decagon Devices, Pullman, WA, USA) at incremental soil depths of 0-6, 6-12, and 12-18 in. Results showed significantly greater average daily sap flow, leaf area index, leaf water potentials, and soil moisture measurements for the daily irrigation treatment. Average soil volumetric water content (VWC) measured in daily schedule was estimated to be 0.08 cm³ cm^-3, 17% and 41% higher than that measured under IFAS or intermediate, respectively. A second study estimated water use and crop coefficients (Kc) as affected by ET and HLB. Two orange varieties (Hamlin and Valencia) with twelve weighing lysimeters per variety (6-HLB infected and 6-non-infected trees) were used to determine daily water use. Crop coefficients (Ks) were estimated by comparing daily water use to daily ET calculated as described by Penman-Monteith (FAO-56 Method). Results showed significant reduction in water use and Kc for infected trees when compared to non-infected ones (control). Citrus water use values under HLB diseased trees averaged almost 25 percent lower than that under healthy trees during the two year study. Therefore, crop coefficients under diseased trees were less than those of healthy Hamlin and Valencia trees, respectively. This led to higher soil water content under HLB infected trees estimated to be 81% and 84% greater than that under healthy Hamlin and Valencia trees, respectively. In addition, leaf Ca declined by 31 and 41% while Mg declined by 20 and 33% in infected Hamlin and Valencia trees, respectively. In contrast, leaf Zn in healthy trees significantly increased by 396% and 360% when compared to infected Hamlin and Valencia trees, respectively.</p><br /> <p><strong>(KS)</strong> An irrigation scheduling field study concerning usage of crop coefficients based on thermal units was continued at the KSU Northwest Research-Extension Center at Colby, Kansas. The field data for the 2015 season has been collected and will be analyzed during the winter months.</p><br /> <p><strong>(NE)</strong> Several research projects, including investigation of irrigation frequency response to evapotranspiration and crop coefficients of corn; planting date and planting population density impact(s) on soybean evapotranspiration, and comparison of center pivot and SDI for evaporation, transpiration, evapotranspiration and crop water productivity parameters were conducted. Sweet corn and watermelon evapotranspiration and crop coefficients research projects have been initiated and the first year of data collection has been completed.</p><br /> <p><strong>(NM)</strong> Three soil moisture content sensors (CS616, Hydra-probe, and 5TM. Both CS616 and Hydra probe) were calibrated and use to schedule irrigation for the partial rootzone drying experiments conducted in the greenhouse for NuMex <em>Joe Parker chile</em>. Experiments were conducted using saline water and sensor calibration and irrigation scheduling was done using Hydra sensors. A greenhouse was instrumented with meteorology sensors and reference ET was calculated using Priestley-Taylor (PT) and Penman-Monteith (PM) equation. PT equation slightly underestimated ETr compared to the PM equation possibly due to its reliance on the solar radiation and temperature only and its neglect of the aerodynamic term. Stem water potential was also measured to check the timing of irrigation, however, being a destructive method only three measurements were made during the growing season.</p><br /> <p><strong>(NY)</strong> A trial was established at 5 different locations across NY state to manage soil water level according to the Cornell-irrigated irrigation model to minimize water stress while other trees were left unirrigated. Less stress was observed for Cornell-irrigated trees than unirrigated trees, however, these results were mainly important for Hudson Valley, where the recorded rainfall was not enough to compensate the ET. Significantly smaller fruits were also harvested in Hudson on the non-irrigated trees. No significant differences were observed for yield and number of fruits.</p><br /> <p><strong>(OK)</strong> A total of seven demonstration sites were developed across the state, where different types of soil moisture sensors were used to train producers on different aspects of using sensor-based information to determine irrigation timing and amount. These sites included four cotton fields under subsurface drip irrigation, center pivot sprinkler, and flood irrigation systems, as well as a pecan orchard, a vineyard, and a commercial nursery. In addition, soil moisture and canopy temperature sensors were used research projects in Oklahoma Panhandle.</p><br /> <p><strong>(OR)</strong> An initial irrigation scheduling trial for drip-irrigated stevia was conducted during 2015 with irrigation onset criteria of 10, 20, 40, 60, and 80 kPa. Water application amounts were kept small to minimize deep water percolation. Steviol glycosides are desired as natural non-caloric sweeteners. Stevia leaf and steviol glycoside production was greatest at the wettest irrigation criteria tested. The ratio of the individual steviol glycosides harvested in the leaves varied with the irrigation criteria. Twenty eight replicated irrigation trials were conducted in 2015 to help determine the irrigations water requirements for economically viable commercial production of native wildflower seed. By burying drip tapes at 12-inch depth and avoiding wetting the soil surface, we hoped to assure flowering and seed set without undue encouragement of weeds or opportunistic diseases. Each species received 0, 100, and 200 mm of irrigation water, and seed yields were measured. Species varied substantially in their needs for supplemental irrigation water, from 0 to 200 mm/yr. In 2014 and 2015 an IRROmesh&trade; system that used a SensMitWeb&trade; smartmesh radio platform was tested. The system read soil temperature and soil water tension using three Watermark&trade; soil moisture sensors in each of twelve fields planted to eight different crops. Real time soil data and graphs of soil water tension trends were easily accessible by smart phone. These preliminary trials using the sensor web showed that this technology holds potential for saving time, increasing accuracy of irrigation scheduling, and assuring yield.</p><br /> <p><strong>(TX, A&amp;M)</strong> A two-year project, &ldquo;Higher Integration Networking, Texas High Plains Evapotranspiration Network,&rdquo; sponsored by the Texas Water Development Board via Panhandle Regional Planning Commission was completed. This work supported a graduate student and provided public access to adapted and user-friendly packaged ET-based crop water use information and related agricultural meteorological data. End users of the information included agricultural irrigators; agricultural, environmental and other research programs; water resources managers/agencies; crop insurance companies and agencies; municipalities, turf managers, homeowners; environmental consultants and researchers; and educators. The &ldquo;Extension Portal&rdquo; supported through this project served as a public gateway to information available from the Texas High Plains Evapotranspiration (TXHPET) Network. Internet access to crop water use estimates, an online irrigation scheduling tool, information and educational resources were provided through this gateway. While the tools and resource materials were broadly applicable to a wide range of audiences and conditions, the crop water use data are regionally focused in the Texas High Plains (Panhandle and South Plains) where the majority of irrigation water in the state is used, as well as portions of the Rolling Plains and West Texas. The products of this effort support Regional Water Planning agricultural water conservation strategies. The project leveraged the Texas High Plains ET Network resources by 1) providing public access to agriculturally appropriate weather data and crop water use estimates; and 2) promoting proficient use of the data through educational programs. The Texas High Plains ET Network Water Management Website (Extension Portal) provided convenient access to timely, pertinent, summarized and interpreted weather data and crop water use estimates to support improved irrigation water management. Estimated potential water conservation resulting from this project are in the range of 0.5 -2.0 ac-inches/irrigated acre, depending upon level of adoption and well capacity and crops produced, with higher potential savings in areas with greater irrigation capacity such as in the Panhandle and Northern Texas High Plains.</p><br /> <p><strong>(TX, USDA)</strong> Two TDR-type soil water sensors (CS-655 and Acclima TDR-315) were compared and TDR-315 sensors were more sensitive to soil water fluxes as compared with Campbell Scientific CS-655 soil water sensors when deployed in plots of irrigated sorghum. A wireless distributed network of soil water sensors (CS CR206X dataloggers, CS-655 and TDR-315 soil water sensors) were integrated with a plant sensing (infrared thermometry) and weather-based system for irrigation scheduling of grain sorghum. Acclima TDR-315 sensors indicated trends of soil water depletion, while CWSI calculations indicated no water stress during extended periods of cloud cover. Soil water measurements with the neutron probe also indicated significant soil water depletion in the root zone during this same period.</p><br /> <p>Commercial wireless infrared thermometers were deployed over corn to test reliability of wireless transmission over a 230 m range. Data was consistently captured from 90% of the wireless IRTs throughout the irrigation season. Percent packet reception was approximately 98% per sensor. Data was captured using a proprietary Windows-based graphical user interface. A plant feedback method using canopy temperature sensing and a CWSI threshold can be used for irrigation scheduling of cotton and provide lint yields similar to manual irrigation scheduling using a neutron moisture meter and replenishing soil water depletion to field capacity in a semi-arid area.</p><br /> <p><strong>(VI)</strong> An automated system powered by solar energy was developed to monitor soil volumetric water content (VWC) and to control irrigation. The system was tested in the laboratory and at two independent experimental locations cultivated with kale (<em>Brassica oleracea</em> var. sabellica) and sweet pepper (<em>Capsicum annuum</em>) &lsquo;Cubanelle&rsquo;. A low-cost and open-source microcontroller (Mega; Arduino, Ivrea, Italy) with a logging shield (model 2.0; Adafruit, New York, NY) connected to twelve capacitance soil moisture sensors (10HS; Decagon Devices, Pullman, WA) was used. The system was powered by a 15-W solar panel connected to a 12/24VDC charge controller and two 12VDC 7.2 Ah batteries. The technology is accessible and relatively inexpensive (microcontroller and accessories cost $150 and each sensor cost $115). This system effectively monitored VWC over time. The irrigation controller required little maintenance over the course of both trials. The microcontroller can be used with latching 6 to 18-V direct current (DC) solenoid valves to control irrigation based on real-time readings. The low cost of this irrigation controller makes it useful in many applications, including both research and commercial production.</p><br /> <p><strong>(WA)</strong> Subsurface irrigation research trials were conducted in the Yakima Valley vineyards to evaluate opportunities to conserve water, energy and pesticide use while producing superior quality grapes. At early veraison, the lowest rate of irrigation delivered subsurface exhibited more stress than the full irrigation rate delivered by surface drip, regardless of whether applied as pulse or constant rates. Cluster weights at mid-veraison were lower for all subsurface delivery (SSD) treatments applied at reduced amounts of water using pulsed application than were clusters sampled from the surface drip (SD) full commercial rate treatment. By contrast, cluster weights from SSD treatments applied at constant application were similar between SD and SDD treatments, regardless of water amount or depth of water delivery. Clusters from SSD treatments applied in pulses of water had lower numbers of berries per cluster than clusters from the SD treatment, but were more similar in number in the SDD treatments with 30 and 60 percent of water applied. By contrast, all SSD treatments were found to have greater numbers of berries per cluster than SD, regardless of amount of water applied or depth of water delivery. Individual berry weights were generally lower for the SDD treatments whether applied under pulse or constant delivery. At harvest, total fruit production was weighed from each vine. While production was greater from vines receiving commercial rates of irrigation, production from the subsurface treatments was possible under rates as low as 15 % of the commercial rate. A subsurface delivery system was installed within a 12-year old block of Concord grapes located on the Roza Unit of the WSU Prosser-Irrigated Agriculture Research and Extension Center near Prosser, WA during 2014 and date collection began during the 2015 growing season &ndash; one of the hottest and driest periods on record. Standard surface drip irrigation is compared to sub-surface drip irrigation delivered at 1-, 2-, 3- and 4-feet below the soil surface. The experimental design employs a split-plot sub-treatment with 3 replications to compare differences in plant response to full-rate irrigation (8 gallons per plant) and half-rate irrigation (4 gallons per plant) per irrigation date, as scheduled by estimated E/T rates and measured stem xylem pressure potential. Data collection in 2015 was terminated when water delivery was interrupted by the irrigation district as a result of water shortage and the fact that the site was located on a junior water right. The experiment will be repeated during the 2016 growing season.</p><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li><strong>Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</strong></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>(AL)</strong> Developed 2 funded proposals on the use of UAV&rsquo;s for real-time assessment and management of soil moisture.</p><br /> <p><strong>(AZ)</strong> A field study to understand the effect of salinity on corn yield and development under subsurface drip irrigated field was conducted at the University of Arizona&rsquo;s Campus Agricultural Center, Tucson, Arizona. Data on salinity and plant factors such as plant height, plant dry mass, root dry mass, tasseling, and silking, was collected and analyzed, and a salinity response function for field corn under arid conditions was developed. The result showed that corn yield, shoot growth, plant height and root development decreased with increased salt concentration. Silking and tasseling were also delayed at higher salt concentrations. The statistics showed significant difference between the four treatments during different growth stages. Although the highest concentration of salts was accumulated in the shallow layer, salinity greatly affected distribution of corn roots in the soil and this influenced the uptake of water and nutrients. During the vegetative stage of the plant, roots grew rapidly. After this stage root growth generally increased at a slower rate than shoot growth and after the reproductive stage root dry mass declined, which has been associated with the translocation of N in the roots to the developing ear.</p><br /> <p>The corresponding response function of yield to salinity was Y = 9.276 &ndash; 0.51(ECe &ndash; 1.32) for ECe &gt; 1.32, and Y = 9.276 for EC&lt; or = 1.32.</p><br /> <p><strong>(CA)</strong> Subsurface monitoring capabilities for soil moisture, soil nitrate, salinity, and leaching of water and nitrate across various micro-irrigated agricultural fields, with most in tree crops (almond, pistachio, citrus, walnut) were installed. The soil water balance (WB) and Darcy law (DL) methods to estimate leaching were applied to assess field-scale leaching rates and their variations for an almond orchard, comparing drip and fanjet micro-irrigation systems. Evapotranspiration rates and unsaturated hydraulic conductivity values are the main sources of uncertainties for the WB and DL method, respectively. The Darcy law approach was found to be a more informative approach. It is suggested that in-situ measurements of soil water dynamics are coupled with numerical simulation modeling to obtain improved field-scale estimates of the soil hydraulic properties, using the inverse modeling approach.</p><br /> <p><strong>(CO)</strong> In 2015, a study was conducted to study water use and salt distribution patterns in the soil profile for muskmelon grown with drip irrigation. The electrical conductivity (EC) of the ground water source was 2.8 ds.m^-1. The timing and amounts of irrigations were based on data collected from a nearby weather station. Seasonal changes in soil moisture and salinity distribution were monitored via data loggers/soil probes and a neutron moisture meter. During the growing season, a total of 9.8 acre-inches of water was applied through the drip system. An additional 1.9 acre-inches was added via precipitation. Muskmelons grown with a saline water source had comparable yields and qualities to those grown with higher quality water. Post-season soil samples were collected and salt distribution patterns in the soil profile were also assessed. The overall water use efficiency and salt distribution patterns will be determined and reported in a subsequent report.</p><br /> <p><strong>(KS)</strong> Two field studies were initiated at NWREC to evaluate in-season fertigation with macronutrients (N and P) and microelements (primarily Zinc) for field corn production. A field study examining precision mobile drip irrigation (PMDI) where driplines are attached to a moving center pivot platform was initiated at the KSU Southwest Research-Extension Center at Garden City, Kansas. A preliminary exploratory study was conducted at NWREC to evaluate the potential for narrow row spacing of corn when grown with subsurface drip irrigation (SDI). This latter study is laying groundwork for future collaboration with Chinese Agricultural University, Beijing China. The field data for the 2015 season for all these studies has been collected and will be analyzed during the winter months. A review of subsurface drip irrigation for 4 crops (tomato, cotton, corn and onion) was presented at an international symposium in November 2015 and has been accepted for publication in a refereed journal in 2016. A small international conference was coordinated with Chinese Agricultural University and a presentation on usage of on SDI under varying constraints was presented.</p><br /> <p><strong>(OK)</strong> A research project was initiated in 2014 at the OSU Panhandle Research and Extension Center near Goodwell, OK on &ldquo;Developing Management Strategies for Subsurface Drip Irrigation in the Oklahoma Panhandle.&rdquo; The objective of this project was to evaluate how crop row placement will influence corn and grain sorghum yield response at irrigation regimes of 50, 75, and 100% of full irrigation. This project continued in 2015 growing season and will be repeated in 2016 as well.</p><br /> <p><strong>(OR)</strong> Various N, P, and K applications strategies have been compared from 2013 - 2015 in replicated yield trials based on information collected by soil analysis, plant tissue analysis, and soil solution sampling. Soil solution sampling seems to provide the fewest positive feedback signals for fertilization, yet results in production without yield reductions. Work in 2014 and 2015 has explored rates and timings of applying Outlook herbicide through drip irrigation for yellow nutsedge control. This method of application shows promise for yellow nutsedge control but is not currently labeled. Tests in 2014 and 2015 have examined options to manage soil borne diseases via the application of fungicides through the drip irrigation system. These application methods are not yet labeled, so they are not being promoted. . In 2013- 2015 furrow irrigation using canal water with moderate or high levels of <em>E. coli</em> contamination and drip irrigation using canal water and well water free of <em>E. coli</em> were tested<em>.</em> Water was sampled hourly for <em>E. coli </em>and the lateral movement of <em>E. coli </em>in the soil solution was measured at the end of irrigations. Onions were sampled for <em>E. coli </em>contamination. Under furrow irrigation, the soil filtered out most of the <em>E. coli </em>between the edge of the water and the soil immediately adjacent to the onion bulbs. <em>E. coli </em>movement under drip irrigation was mostly confined to near the drip tape, with relatively little reaching the proximity of the onion bulbs. Chlorine dioxide at 1 and 3 ppm through drip irrigation was tested to reduce generic <em>E. coli</em> in water delivered to commercial onion fields in 2014 and 2015. Chlorine dioxide substantially reduced <em>E. coli</em> counts at all sampled locations and concentrations.</p><br /> <p><strong>(PR)</strong> A citrus orchard (lemon cv. &lsquo;Meyer&rsquo;) was planted in May 2014 in a soil classified as Vertisol including factoral treatments of bed type (plastic mulch vs. bare beds [conventional]) and fertility (fertigation vs foliar spray vs combined). To improve comparison statistical strength two checks were established (first, granular fertilizer recommendations and second is the absolute control (no fertilizer and drip irrigation applications). Variables being measured are: canopy volume, trunk diameter, and nutrient content in the foliar tissue, soil moisture, and water applied. Also, trees were sampled for HLB and vector population. One year after planting HLB samplings indicate that trees submitted to five of the eight treatments were positive for HLB. All other variables still under collection and need further analysis. An experiment was performed to correlate soil moisture reading (soil water tension) with leaf water potential (pressure chamber) in fourteen-year old avocado trees. A significant correlation of r = 0.52 was obtained between soil water tensions and leaf water potential. Soil water tensions values greater than 70 kPa were correlated with leaf water potential values less than 900 kPa, indicating that trees were not necessarily in water stress. The analysis also showed that avocado trees submitted to low soil water tensions significantly produced lower yields. Published data from the same orchard indicate that avocado trees submitted to soil water tension of 40 to 45 KPa significantly increased trees growth and productivity. A trial was established to determine the effect of various management systems on tanier (Xanthosoma spp.) production in the south coast of Puerto Rico. Three factors were evaluated; drip irrigation system vs subsurface drip irrigation (SDI), plant densities (7,050 vs. 9,401 plants per acre); and two varieties (Estela and Nazareno ). Among the collected data is main corm weight, percentage of damage caused by dry root rot syndrome, commercial corm number and weight. Another malanga Lila (<em>Colocasia esculenta</em>) experiment was established proving subsurface drip irrigation management systems to assess two planting densities (10,560 and 14,100 plants per acre). It is planned to eliminate the use of beds for malanga lila production in the south coast of Puerto Rico. In this new system, plastic mulch and drip irrigation lines are installed right after land preparation. A project was established to validate /calibrate remotely sensed solar radiation, which forms the basis of ET calculations, and to automate the entire system via a public website for PR, USVI, Hispaniola, Jamaica and Cuba (<a href="http://pragwater.com">http://pragwater.com</a>).</p><br /> <p><strong>(TX)</strong> An SDI system was installed on a 1-ha area to optimize management for cotton germination, with the field experiment beginning in 2013 and continuing for the third year in 2015. The factors considered are SDI lateral/row position and planting date. 2013 results showed highest yield in early planted treatments, and 2014 results showed relatively small differences in yield due to planting date or row/lateral arrangement due to higher than average season rain. 2015 harvest results were non-conclusive due to a severe hail event on August 28. This experiment will ultimately provide economic comparisons of water value (crop yield) relative to initial irrigation system cost and management.</p><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><strong>Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</strong></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>(AZ) </strong>A computer program that was developed for designing low-head bubbler irrigation system was rewritten in HTML format to be available on the World Wide Web.</p><br /> <p><strong>(CO)</strong> In 2015, the website, <a href="http://www.coloradoproduce.org">www.coloradoproduce.org</a>, was further developed and promoted as a delivery mechanism for research-based information to Colorado specialty crop growers.</p><br /> <p><strong>(KS)</strong> Presentations have been made at a regional irrigation meeting and the SWREC Field Day for irrigators and nationally for scientists and engineers at the technical conference of the Irrigation Association.</p><br /> <p><strong>(NY)</strong> A web-based apple transpiration model, which allows NY State apple growers to estimate irrigation requirements for NY apple orchards of various ages was developed. The interface links the model with three data input sources: (1) Grower supplied orchard-specific parameters, including tree density, orchard age and green tip date; (2) Hourly meteorological data for the previous seven days accessed from the Applied Climate Information System (ACIS). Temperature, humidity, wind speed and solar radiation are the necessary variables that are used and are supplied from either grower-operated weather stations or, in some cases, existing federally supported weather networks. Data from both sources are accessible via ACIS. (3) Forecast weather data for the location of the orchard are extracted from the National Digital Forecast Database (NDFD). The NDFD is a gridded product created by the National Weather Service that provides forecast information for up to seven days into the future on a 5 km x 5 km grid. Solar radiation forecasts are not provided directly by NDFD, but are estimated based on forecast sky cover data from NDFD using a solar radiation model developed by the Northeast Regional Climate Center.</p><br /> <p><strong>(OK)</strong> Information on science-based irrigation scheduling was presented at five national conferences, four regional meetings and in-service trainings, and five field days and crop tours. The 2nd Oklahoma Irrigation Conference was held in August, with invited irrigation specialists from Oklahoma, Kansas, and Texas to train Oklahoma producers on improving irrigation management. Three presentations were on the specific topic of implementing ET-based and sensor-based irrigation scheduling. Eighty eight people attended this one-day conference.</p><br /> <p><strong>(TX)</strong> A team of scientists from Texas A&amp;M AgriLife Research and Extension and a group of computer programmers from the Texas A&amp;M Center for Applied Technology (TCAT) has developed prototype software and recently conducted the first software review by external users for a web-based cotton irrigation management software called DIEM - dashboard for irrigation efficiency management. Members of the team have also conducted additional field scale evaluations on producer's fields to validate the original research findings. The High Plains Irrigation Conference in Amarillo, Texas in January 2015 addressed topics of interest to agricultural producers, irrigation professionals, landowners and federal and state agency personnel participated in this one-day event that offered CEUs for Irrigation Association Certified Irrigation Professionals (Certified Irrigation Designers and Certified Agricultural Irrigation Specialists) and Agronomy Society Certified Crop Advisers. Of the survey respondents, 90% indicated increased&nbsp;understanding of regional and state water issues, planning and programs; 69% indicated increased understanding of risk management considerations and tools; 72% indicated increased understanding of crop-specific water management considerations; 83% indicated increased understanding of information resources, research programs and expertise available; 64% indicated increased understanding of efficient irrigation strategies and technologies; and 61% indicated increased understanding of irrigation products and services available. All (100%) of respondents indicated that the information provided in the program would be helpful in their irrigation decisions. Several indicated specific technologies and/or practices they would implement as a result of what they learned in the program. Extensive local radio and television media coverage promoted highlights of the event throughout the region. One local radio station broadcast the entire event live and re-broadcast portions of the event at later dates.</p><br /> <p><strong>(VI)</strong> Two independent systems were developed using soil moisture and EC sensors to control irrigation and fertigation in geranium (<em>Pelargonium &times;hortorum</em> Bailey) &lsquo;Maverick Violet&rsquo; grown in 6-inch pots with peat:perlite substrate. Pore water electrical conductivity (EC), temperature, and volumetric water content (VWC) data were collected, added to a database, and made available online. A web application using twitter/BootStrap was written to query the databases and provided graphs online. The system did not control irrigation and fertigation properly. The connection with the database was unstable due to the authentication protocol used by the network and the communication between sensors and microcontrollers was problematic, resulting in random loss of data and storage of unrealistic values. As a result, valves opened at the wrong times, not allowing a precise control. More studies are needed before these microcontrollers can be recommended for agricultural applications.</p>

Publications

<p>Aguilar, J., D. H. Rogers, I. Kisekka, and F. R. Lamm. 2015. SDI applications in Kansas and the US. In: Proc. 27th annual Central Plains Irrigation Conference, Feb. 17-18, 2015, Colby, Kansas. Available from CPIA, 760 N. Thompson, Colby, Kansas. pp. 71-82.</p><br /> <p>&nbsp;</p><br /> <p>Agnello, A.M., Cox, K.D., Dominguez, L., Francescatto, P., Lordan, J., and Robinson, T.L., 2015a. An insect, disease and weed management program for New York organic apples. New York Fruit Quarterly 23.</p><br /> <p>&nbsp;</p><br /> <p>Agnello, A.M., Landers, A., Rosenberger, D.A., Robinson, T.L., Carroll, J.E., Cheng, L., Curtis, P.D., Breth, D.I., and Hoying, S., 2015b. Pest management guidelines for commercial tree-fruit production 2015, p. 252. Cornell University, Ithaca, NY, USA.</p><br /> <p>&nbsp;</p><br /> <p>Bartolo, M.E., K. Tanabe, J. Davidson, and L. Simmons. 2015. Arkansas Valley Research Center Reports, CSU Ag. Expt. Station Technical Report TR15-11.</p><br /> <p>Bhattarai, N., Quackenbush L.J., Dougherty, M., Marzen L.J. 2014. A simple Landsat-MODIS fusion approach to monitor seasonal evapotranspiration at 30 m spatial resolution. International Journal of Remote Sensing 36: 115-143. (<a href="http://dx.doi.org/10.1080/01431161.2014.990645">doi: 10.1080/01431161.2014.990645</a>).</p><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <p>Dobbs, N.A., K.W. Migliaccio, Y.C. Li, M.D. Dukes and K.T. Morgan. 2014. Evaluating irrigation applied and nitrogen leached using different smart irrigation technologies on bahiagrass (Paspalum notatum). Irrigation Science 32:193-203<em>.</em></p><br /> <p>&nbsp;</p><br /> <p>Dominguez, L.I. and Robinson, T.L., 2015. Strategies to improve early growth and yield of Tall Spindle apple plantings. <em>New York Fruit Quarterly</em> 23:5-10.</p><br /> <p>&nbsp;</p><br /> <p>Fazio, G., Cheng, L., Grusak, M.A., and Robinson, T.L., 2015. Apple rootstocks influence mineral nutrient concentration of leaves and fruit. <em>New York Fruit Quarterly</em> 23:11-15.</p><br /> <p>&nbsp;</p><br /> <p>Felix, J., C.C. Shock, J. Ishida, E.B.G. Feibert, L.D. Saunders. 2015. Irrigation criteria and sweetpotato cultivar performance in the Treasure Valley of Eastern Oregon. HortScience 50(7):1011-1017.</p><br /> <p>&nbsp;</p><br /> <p>Gowda, Prasanna H., Terry A. Howell, José L. Chávez, George Paul, Jerry E. Moorhead, Daniel Holman, Thomas H. Marek, Dana O. Porter, Gary H. Marek, Paul D. Colaizzi, Steve R. Evett, and David K. Brauer. 2015. A Decade of Remote Sensing and Evapotranspiration Research at USDA-ARS Conservation and Production Research Laboratory. ASABE Paper Number 2143458. ASABE / IA Irrigation Symposium, &ldquo;Emerging Technologies for Sustainable Irrigation&rdquo;, Long Beach, California, November 10 &ndash; 12, 2015.</p><br /> <p>&nbsp;</p><br /> <p>Harmsen, E. 2015. Irrigation Scheduling Methods Applicable to the Southern Coast of Puerto Rico, Nov 10, 2015, Irrigation Scheduling Workshop, Salinas, Puerto Rico, Nov 10, 2015.</p><br /> <p>&nbsp;</p><br /> <p>Harmsen, E. 2015. Irrigation Requirements in a Changing Climate&nbsp;YouTube Video.</p><br /> <p>&nbsp;</p><br /> <p>Harmsen, E.W., P. Tosado and J. Mecikalski, 2014. Calibration of Selected Pyranometers and Satellite Derived Solar Radiation in Puerto Rico. Int. J. Renewable Energy Technology, 5(1):43-54.</p><br /> <p>&nbsp;</p><br /> <p>Irmak, S., J.E. Specht, L.O. Odhiambo, J.M. Rees, and K.G. Cassman 2015. Soybean yield, water productivity, evapotranspiration and soil-water extraction response to subsurface drip irrigation. <em>Transactions of the ASABE </em>57(3):729-748. DOI 10.13031/trans.57.10085.</p><br /> <p>&nbsp;</p><br /> <p>Kadyampakeni, D.M., and K.T. Morgan. 2014. Nutrient management options for Florida citrus: a review of N,P, and K application and analytical methods. J. Plant Nutrition http://dx.doi.org/10.1080/01904167.2014.934470</p><br /> <p>&nbsp;</p><br /> <p>Kadyampakeni, D.M., K.T. Morgan, A.W. Schumann, P. Nkedi-Kizza. 2014. Effect of irrigation pattern and timing on root density of young citrus trees infected with Huanglongbing disease. HortTechnology 24(2):209-221.</p><br /> <p>&nbsp;</p><br /> <p>Kadyampakeni, D.M., K.T. Morgan, A.W. Schumann, P. Nkedi-Kizza. 2014. Effect of irrigation pattern and timing on root density of young citrus trees infected with Huanglongbing disease. HortTechnology 24(2):209-221.</p><br /> <p>&nbsp;</p><br /> <p>Kadyampakeni, D.M., K.T. Morgan, A.W. Schumann, P. Nkedi-Kizza, and T.A. Obreza. 2014. Water use in drip and microsprinkler irrigated citrus trees as a function of tree size, soil characteristics and Huanglongbing infection. Soil Sci. Soc. Am. J. DOI:10.2136/sssj2014.02.005.</p><br /> <p>&nbsp;</p><br /> <ol start="2015"><br /> <li>Kandelous, B.A. Moradi and J.W. Hopmans. 2015. An alternative tensiometer design for deep vadose zone monitoring. Soil Sci. Soc. Amer. J.&nbsp;&nbsp; 79:1293-1296. DOI:10.2136/sssaj2015.03.0121</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>Kamai, T., G.J. Kluitenberg, and J.W. Hopmans. 2015. A Dual-Probe Heat-Pulse Sensor with Rigid Probes for Improved Soil Water Content Measurements. Soil Sci. Soc. Amer. J. doi:10.1029/2015.</p><br /> <p>&nbsp;</p><br /> <p>Lakso, A.N. and Robinson, T.L., 2015. Decision support for apple thinning based on carbon balance modeling. Acta Hort. 1068:235-242.</p><br /> <p>&nbsp;</p><br /> <p>Lamm, F. R. and D. H. Rogers. 2014. SDI for corn production -A brief review of 25 years of KSU research. In: Proc. 2014 Irrigation Association Technical Conference, Nov. 19-20, Phoenix, AZ. CD-Rom. 12 pp.</p><br /> <p>&nbsp;</p><br /> <p>Lamm, F. R., D. H. Rogers, I. Kisekka, and J.P. Aguilar. 2014. Successful SDI - Addressing the essential issues. In: Proc. 2014 Irrigation Association Technical Conference, Nov. 19-20, Phoenix, AZ. CD-Rom. 15 pp.</p><br /> <p>&nbsp;</p><br /> <p>Lamm, F. R. and D. H. Rogers. 2014. SDI for corn production -A brief review of 25 years of KSU research. In: Proc. 4th Reunion Internacional de Riego &ndash; Uso eficiente del agua para riego. October 15-16, Manfredi, Cordoba Argentina. pp. 86-97.</p><br /> <p>&nbsp;</p><br /> <p>Lamm, F. R. and D. H. Rogers. 2015. Frequently and not-so-frequently asked questions about subsurface drip irrigation. In: Proc. 27th annual Central Plains Irrigation Conference, Feb. 17-18, 2015, Colby, Kansas. Available from CPIA, 760 N. Thompson, Colby, Kansas. pp. 96-107.</p><br /> <p>&nbsp;</p><br /> <p>Lamm, F. R., D. M. O&rsquo;Brien, and D. H. Rogers. 2015. Using the K-State center pivot sprinkler and SDI economic comparison spreadsheet &ndash; 2015. In: Proc. 27th annual Central Plains Irrigation Conference, Feb. 17-18, 2015, Colby, Kansas. Available from CPIA, 760 N. Thompson, Colby, Kansas. pp. 108-116.</p><br /> <p>&nbsp;</p><br /> <p>Marek, Thomas and Dana Porter. 2015. Extension Portal for Higher Integration Networking for Coordination of Training, Information and Research. Final report for Texas Water Development Board Contract Number 1213581481. Texas A&amp;M AgriLife Research and Texas A&amp;M AgriLife Extension Service. Texas A&amp;M University System, College Station, Texas.</p><br /> <p>&nbsp;</p><br /> <p>Mart&iacute;nez-Cruz T. E., Slack D. C., Ogden K. L., and Ottman M. (2014) THE WATER USE OF SWEET SORGHUM AND DEVELOPMENT OF CROP COEFFICIENTS, Irrig. and Drain., doi:10.1002/ird.1882.</p><br /> <p>&nbsp;</p><br /> <p>Miranda Sazo, M. and Robinson, T.L., 2015. Measuring and extending the benefits of orchard mechanization in high density orchards in Western NY. <em>New York Fruit Quarterly</em> 23:25-29.</p><br /> <p>&nbsp;</p><br /> <p>Morgan, K.T., S. Barkataky, D. Kadyampekeni, R. Ebel, and F. Roka. 2014. Effects of short-term drought stress and mechanical harvesting on sweet orange tree health, water uptake, and yield. HortScience 49(6):835-842.</p><br /> <p>&nbsp;</p><br /> <p>Moorhead, Jerry, Prasanna Gowda, Mike Hobbins, Gabriel Senay, George Paul, Thomas Marek, and Dana Porter, 2015. Accuracy Assessment of NOAA Gridded Daily Reference Evapotranspiration for the Texas High Plains. Journal of the American Water Resources Association (JAWRA) 51(5): 1262-1271. DOI: 10.1111/1752-1688.12303.</p><br /> <p>&nbsp;</p><br /> <p>Moser, Kendra, Paul Baumann, Guy Fipps, Clark Neely, Dana Porter and M.O. Way. 2015. Texas Best Management Practices Guide. Texas Soybean Board.</p><br /> <p>&nbsp;</p><br /> <p>Nouiri, I. , M. Yitayew, J. Ma&szlig;mann, J. Tarhouni. 2015. Multi-objective Optimization Tool for Integrated Groundwater Management. Journal of Water Resources Mangement, Volume 29, Issue 14, pp5353-5375</p><br /> <p>&nbsp;</p><br /> <p>O&rsquo;Shaughnessy, S.A., Evett, S.R., Andrade A., Workneh, F., Price, J.A. and Rush, C.M. Site-Specific Variable Rate Irrigation as a Means to Enhance Water Use Efficiency. In Proceedings, 2015 ASABE/IA Irrigation Symposium. Nov 10-12, 2015. Long Beach, Calif. (doi: 10.13031/irrig.2015214448).</p><br /> <p>&nbsp;</p><br /> <p>O'Shaughnessy, S.A., Evett, S.R., and Colaizzi, P.D. Dynamic Prescription Maps for Site-specific Variable Rate Irrigation of Cotton. Agric. Water Manage. 159: 123-138.</p><br /> <p>&nbsp;</p><br /> <p>Odhiambo, L., and S. Irmak. 2015. Relative evaporative losses and water balance in subsurface drip- and center pivot-irrigated soybean fields. <em>J. Irrigation and Drainage Engineering, ASCE</em> 141(11):1-17. 04015020.</p><br /> <p>&nbsp;</p><br /> <p>Porter, Dana. 2015. Advances in Managing Limited Irrigation Water. Invited presentation in Efficient Resource Utilization for Improving Crop Productivity and Environmental Stewardship Symposium. ASA-CSSA-SSSA Annual Meeting, Minneapolis, MN. November 16, 2015.</p><br /> <p>&nbsp;</p><br /> <p>Porter, Dana, Danny Rogers, David Brauer, Thomas Marek, Prasanna Gowda, Freddie Lamm, James Bordovsky, Bridget Guerrero, and Paul Colaizzi. 2015. Promoting OAP Research through Technology</p><br /> <p>Transfer. 2015 Annual Meeting of the USDA-ARS Ogallala Aquifer Program.</p><br /> <p>&nbsp;</p><br /> <p>Porter, Dana, Prasanna Gowda, Thomas Marek, and Jerry Moorhead. 2015. Considerations in Recommending Alternatives to Agriculturally-Based Weather Station Networks for Irrigation Scheduling. (Abstract). 2015 World Environmental and Water Resources Congress. American Society of Civil Engineers Environmental and Water Resources Institute, Austin, TX, May 17-21, 2015.</p><br /> <p>&nbsp;</p><br /> <p>Porter, Dana O., Danny Rogers, David Brauer, Thomas H. Marek, Prasanna H. Gowda, Freddie Lamm, James Bordovsky, Terry A. Howell, Sr. 2015. Promoting Efficient Water Management through Effective Outreach Education in the High Plains and Beyond: Role of the Ogallala Aquifer Program. ASABE Paper Number 2143456. ASABE / IA Irrigation Symposium, &ldquo;Emerging Technologies for Sustainable Irrigation&rdquo;, Long Beach, California, November 10 &ndash; 12, 2015.</p><br /> <p>&nbsp;</p><br /> <p>Prado, J. V., E. Rom&aacute;n-Paoli, R. Tirado-Corbal&aacute;^.2015. Estudio del comportamiento h&iacute;drico en aguacate (<em>Persea americana</em> cv. &ldquo;Simmond&rdquo;) mediante la evaluaci&oacute;n y relaci&oacute;n del potencial h&iacute;drico del suelo y foliar. Puerto Rican Society of Agricultural Sciences&rsquo; Annual Meeting, November 13, 2015 Coamo. Puerto Rico.</p><br /> <p>&nbsp;</p><br /> <p>Robinson, T.L. and Dominguez, L.I., 2015. Precision pruning to help maximize crop value. <em>New York Fruit Quarterly</em> 23:29-32.</p><br /> <p>&nbsp;</p><br /> <p>Robinson, T.L., Fazio, G., Black, B., and Parra, R., 2015a. Cornell-Geneva apple rootstocks for weak growing scion cultivars. <em>New York Fruit Quarterly</em> 23:21-24.</p><br /> <p>&nbsp;</p><br /> <p>Sadeghi, S. H., R. T. Peters; and F. R. Lamm. 2015. Design of zero slope microirrigation laterals: Effect of the friction factor variation. J. Irrig. Drain Eng. ASCE, ISSN 0733-9437/04015012(9)</p><br /> <p>&nbsp;</p><br /> <p>Sharma P., M.K. Shukla, P. Bosland and R. Steiner. 2015. Physiological responses of greenhouse-grown drip irrigated Chile Pepper under partial root zone drying. Hort. Science. 50 (8): 1224-1229.</p><br /> <p>&nbsp;</p><br /> <p>Shock, C.C., E.B.G. Feibert, N.L. Shaw, M.P. Shock, L.D. Saunders. 2015. Irrigation to enhance native seed production for great basin restoration. Natural Areas Journal 35(1):74-82.</p><br /> <p>&nbsp;</p><br /> <p>Shock, C.C., E.B.G. Feibert, A. Rivera, L.D. Saunders. 2015. Response of onion yield, grade, and financial return to plant population and irrigation system. HortScience 50(9):1312-1318.</p><br /> <p>&nbsp;</p><br /> <p>Shukla M.K. 2015. Water resource management for semi-arid areas: status, problems and opportunities. 27th International Agronomy Week, Sept. 7-11, Durango, Mexico (Key-note speaker).</p><br /> <p>&nbsp;</p><br /> <p>Shukla M.K. and H. Sharma. 2014. Water balance analysis and development of crop coefficient for drip irrigated chile. Soil Science Society America conference, Long Beach, CA, Nov. 2-5.</p><br /> <p>&nbsp;</p><br /> <p>Teegerstrom, T., P. Livingston and D. Slack. 2015. Sweet Sorghum to Ethanol: A Guidance Manual for the Grower. Proceedings of the 8th International Conference of TSAE. Thai Society of Agricultural Engineers. March 17-19, Bangkok, Thailand</p><br /> <p>&nbsp;</p><br /> <p>Waller, P. and M. Yitayew. 2015. Irrigation and Drainage Engineering. Springer Cham Heidelberg, New York, Dordecht, London. ISBN 978-3-319-05698-2.</p><br /> <p>&nbsp;</p><br /> <p>Yitayew, M., and A. Barreto. 2015 http://cals.arizona.edu/research/bubbler/&nbsp;&nbsp; BUBBLER Design of Low-Head Gravity-Flow Bubbler Irrigation Systems for Trees, Vines and Orchard Crops.</p>

Impact Statements

1. (VI) The use of an energy-efficient technology for soil sensing and irrigation control will eliminate the electrical power dependency and allow the developed system to be used in remote locations.

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Report Information

Participants

Morgan, Kelly (conserve@ufl.edu) – University of Florida; Jacoby, Pete (jacoby@wsu.edu) – Washington State University; Rein, Brad (BREIN@NIFA.USDA.EDU) – NIFA, USDA; Lamm, Freddie (flamm@ksu.edu) – Kansas State University; Shock, Clinton (clinton.shock@oregonstate.edu) – Oregon State University; Neibling, Howard (hneiblin@uidaho.edu) – University of Idaho; Simunek, Jirka (jsimunek@ucr.edu) – University of California – Riverside; Taghvaeian, Selah (saleh.taghvaeian@okstate.edu) – Oklahoma State University; Wright, Glenn (gwright@email.arizona.edu) – University of Arizona; Kadyampakeni, Davie (dkadyampakeni@ufl.edu) – University of Florida; Loring, Steve (sloring@nmsu.edu) – University of New Mexico; Lordan, Jaume (jl3325@cornell.edu) – Cornell University; Fares, Ali (alfares@pvamu.edu) – Prairie View A&M University; Awal, Pipendra (riawal@pvamu.edu) – Prairie View A&M University

Brief Summary of Minutes

The annual meeting was held on Saturday, November 5, 2016 in the Ellis Room of the Hyatt Regency in Phoenix, Arizona. Committee Chair, Dr. Kelly Morgan, called the meeting to order at 8:30 am and reviewed the agenda. No changes to the agenda were made and introductions were individually made by each attendee. Dr. Freddie Lamm (Kansas State University) gave a brief report of the webinar that had been previously planned at the Long Beach meeting (2015). The webinar failed to be initiated and the funds to be used for it were returned. There are no immediate plans to organize an educational program by the central committee; however, Dr. Lamm indicated that he would contact some individuals to pursue means of conducting a webinar during the upcoming year on water quality and clogging. Some of the committee members have been engaged in extension education activities to promote the topic areas of water quality, water use efficiency, and advancements in subsurface micro-irrigation. Dr. Lamm introduced the possibility of having voluntary webinars or related types of programs each year developed by committee members. Dr. Pete Jacoby (Washington State University) introduced another potential area for education programming around the issue of gopher damage to buried driplines. Committee members offered examples of efforts being used around the nation. This issue could be a topic for future webinar and the committee may confer by tele-conference about developing a webinar.  

The business meeting commenced at 9:00 am. The subject of selecting the next site for the committee meeting was undecided after some discussion of potential locations. This item will pass to the 2017 committee chair, Pete Jacoby, for soliciting further input and final decision on the site and time for the 2017 committee meeting. Past meetings have been planned in conjunction of professional meetings, including the Irrigation Association (2015) and the Tri-Society (ASA, CSSA, and SSSA) meeting (2016). Both of these annual profession society meetings typically call in late fall and both will be held in central Florida during 2017.

Dr. Bradley Rein (NIFA – USDA) reported to the committee regarding issues and opportunities at the federal agency levels that could be considered by committee members. Dr. Rein informed the committee about some new hires within NIFA, one of which has Ag Engineering background and training and one who is a social scientist who will work on translating research findings for more rapid adoption by end users. The majority of Dr. Rein’s report addressed new grant opportunities related to the committee’s research interests. A walk-through demonstration of the NIFA website was helpful in guiding committee members to sources of new grant opportunities and RFA’s.

We also heard from Dr. Steve Loring (New Mexico State University) and ended our business meeting portion at mid-morning.

Accomplishments

<p><strong>Florida &ndash;</strong> Turf App</p><br /> <p>Irrigation depths applied resulted in significant water savings with the smartphone app and ET controller treatments; irrigation water savings ranged from 42% to 57% compared to the time based schedule. The turf smartphone app irrigation schedule was similar to the ET controllers with savings always significantly greater than the time-based treatment with varying similarities to the two ET controllers. One difference observed between the app and ET controller schedules was found in the seasonal comparisons where both ET controllers had a greater irrigation rate during the dry season while the app had a greater irrigation rate during the wet season. The irrigation depths applied were not significantly different for the app and ET controller for all data and dry season data. However, differences in irrigation depths for the app and ET controller were observed during wet season and may be due to the different methods of integrating rainfall into the irrigation schedule for these two treatments. Overall the smartphone app performed similar to that of the ET controllers and provides an alternative for users where an ET controller is not a viable option. The seasonal water conservation option on the app would provide some incorporation of rainfall into the schedule. For our study, using this feature would have resulted in a reduction in irrigation to 989 mm from 1086 mm with seasonal totals of 568 mm for wet season and 421 mm for dry season. Thus, the lack of on-site rainfall data can be minimized by using the seasonal water conservation mode in the smartphone app.</p><br /> <p>&nbsp;</p><br /> <p><strong>Florida - </strong>Cotton app</p><br /> <p>The Cotton app was validated results in five commercial cotton fields in southern Georgia. Validation was done with the model using the 2013 calibrated Kc curve. 2013 and 2015 were wetter than normal years while 2014 was a drier than normal year. The Cotton App outperformed the Checkbook Method in terms of mean yield regardless of tillage treatment and did this most effectively during the two wet years. However the differences were statistically significantly different only in 2013 and 2014 because of large intra-treatment variability in yield during 2015. The Cotton App also outperformed the Checkbook Method in irrigation water applied and water use efficiency. This is because the Checkbook Method does not take into account periods with low ET which occur frequently in wet years. The Cotton App outperformed the UGA SSA method in 2014 but in 2015, the UGA SSA conservation tillage treatment outperformed the Cotton App conservation tillage plots. By comparing the soil water tension data from all the treatments and replicated plots, it is clear that in 2015, the treatments that maintained a drier soil profile produced the highest yields. The UGA SSA conservation tillage treatment did have a drier soil profile than the Cotton App. We hypothesize that because the Cotton App does not currently discriminate between conventional and conservation tillage, in 2015 the conservation tillage plots were over-irrigated by the Cotton App.</p><br /> <p>&nbsp;</p><br /> <p><strong>Florida - </strong>Citrus app</p><br /> <p>The Citrus App requires information on tree spacing (in row and between rows), soil water holding capacity, irrigation system output, and ET source. Water balance estimated using day of year and phenology-based Kc to estimate irrigation quantity and frequency requirements. Evaluation was conducted at three commercial citrus orchards in central and south Florida. The experiment was arranged in a randomized complete block design with four replications at each location. Three irrigation scheduling treatments for conventional irrigation were as follows: 1) Citrus App, 2) Grower determined irrigation, 3) Current University of Florida (UF/IFAS) recommended scheduling. Use of the citrus app consistently resulted in lower water use. Note, citrus trees in Florida have become affected by Citrus Greening disease since 2005 and all trees at the three locations in this study was determined to be infected by the pathogen. Water applications were significantly lower using the citrus app (3 out of 3 locations) and UF/IFAS recommendations (1 out of 3 locations) compared with grower schedules. Thus the citrus app used an average of 24% less water than the other two irrigation schedules. Citrus tree sap flow measurements were significantly greater and stem water potential lower for trees irrigated based on schedules produced by the citrus app and current UF/IFAS recommendations compared with trees irrigated using grower&rsquo;s experience. As a result of lower water stress, yields were significantly greater for the citrus app (3 out of 3 locations) than the UF/IFAS recommendations and grower applications. Average increase in yield during the three years of the study was 18%. Yields in Florida citrus orchards have declined by 33% to 50% or more during the past 10 years making the results of this study more noteworthy.</p><br /> <p>&nbsp;</p><br /> <p><strong>Florida - </strong>Peanut app</p><br /> <p>&nbsp;</p><br /> <p>The peanut crop season started on 19 May (planting day) and ended on 16 October 2015 (digging day). During the crop season, cumulative rainfall and calculated ET_c summed up to 26.9 and 20.4 inches, respectively. The first irrigation event occurred on 10 July (52 DAP), when irrigation treatments started. Cumulative irrigation applied per treatment was: 5.2,for grower irrigation schedule, 0.5 for the app schedule, and 1.0 for the soil moisture sensor treatment. Therefore, irrigation treatments applied about 90%, 81% less water than the peanut grower&rsquo;s irrigation practices. Due to the consistent rainfall patterns, peanut required relatively little irrigation throughout the season.</p><br /> <p>&nbsp;</p><br /> <table><br /> <tbody><br /> <tr><br /> <td><br /> <p><strong>Alabama</strong> &ndash; Use of field soil tension measurement in soybeans has been investigated over the past two years on three sites in Alabama.&nbsp; The goal of the research is to develop crop coefficients for soybeans using field tension monitoring and accessible for smart irrigation scheduling. Currently supervising replicated SDI fertigation plots (cotton) in northern Alabama with capability to manually adjust timing of nutrient injection throughout the season.&nbsp; Nine years of subsurface drip irrigation with corresponding cotton yield and daily weather data collection has been completed with replicated research plot study.&nbsp; Results planned for publication 2017.</p><br /> </td><br /> </tr><br /> </tbody><br /> </table><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong>California</strong> (UC Davis) - The evapotranspiration (ET) of an almond tree planted in 2015 was measured lysimetrically, and compared to the ET predicted from a recently published young peach tree model. Measured values were substantially higher (about double) than predicted by the model, but this will be confirmed with further study. The soil and tree components of the model were separated by periodically covering the soil surface, and most of the discrepancy between the measured and modeled values was due to an underestimate of the tree component. Micrometeorological methods to measure ET over a mature commercial almond orchard canopy indicated that canopy ET is not reduced during stress, despite reductions in stomatal conductance. This result was unexpected, and may indicate that a decline in water use efficiency occurs during stress in almonds. A multi-year almond water production function experiment was continued, and thus far the yield effects of reduced irrigation have been minimal (reductions of from 5 - 25%, depending on location), despite imposing a relatively wide range of irrigation amounts (from 40-60"). A multi-year study was initiated to document the long term effects on tree and root health of winter flood irrigations in almond orchards for the purpose of groundwater recharge. Thus far, no negative effects have been observed by applying an additional 24" of water during the dormant season (December/January). The second year of an ongoing walnut irrigation test was performed and demonstrated that plant-based measurements (stem water potential, SWP) could be used to delay the first irrigation in the spring by about 1 month, with no detrimental effects on yield, and evidence was obtained that this practice may improve root health over the long term (years).</p><br /> <p>&nbsp;</p><br /> <p><strong>California</strong> (UC Riverside) - In 2016 we offered short (three-day) courses on how to use HYDRUS models at a) Colorado School of Mines, Golden, CO, b) Czech University of Life Sciences, Prague, Czech Republic, and c) the Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, Peoples Republic of China. About 100 students participated in these short courses.</p><br /> <p>&nbsp;</p><br /> <p><strong>Florida - </strong>We initiated micro-irrigation projects in Ghana, Burkina Faso and Mali on water- and labor saving drip and sprinkler irrigation technologies for production of onion, tomato and potato. Water savings were in the range of 20 to 40% over traditional irrigation practices.&nbsp; In Florida, micro-irrigation technologies have led to reduction in nutrient leaching, increased water and nutrient uptake in citrus.</p><br /> <p>&nbsp;</p><br /> <p><strong>Idaho</strong> - A web-based water-budget irrigation scheduling program developed by Dr. Troy Peters, WSU, and a soil sensor based approach were compared in several Eastern Idaho farm field sites irrigated by center pivot in 2016.</p><br /> <ul><br /> <li>4 Watermark granular matrix sensors, tipping bucket rain gage and an AgSense data logger with cell phone transmission, and web-based data storage and retrieval were used on each of 3 malting barley sites, and on 2 potato sites.</li><br /> <li>4 Decagon EC-10 soil water sensors and an Onset data logger with cell phone transmission and web-based data storage and retrieval equipment were used on 2 alfalfa sites, and</li><br /> <li>4 Decagon EC-5 soil water sensors, a tipping bucket rain gage and Decagon data loggers were used on 2 alfalfa sites.</li><br /> </ul><br /> <p>&nbsp;</p><br /> <p>The WSU &ldquo;Irrigation Scheduler Remote&rdquo; program used irrigator-selected soil and crop parameters, AgriMet daily estimated crop ET, and rainfall, and irrigator-input irrigation data to evaluate root zone available soil water and depth of irrigation water required to re-fill the root zone on a daily basis.</p><br /> <p>Soil sensors were installed at 4 depths (12, 18, 24 and 30 inches) on each site to serve as a daily comparison measurement.&nbsp; In the first two sets of equipment, data from the sensors and a tipping bucket rain gage (where available) were transmitted by cell phone link to a website at 30-minute intervals.&nbsp; This information, formatted in a user-defined fashion, was available from any mobile device (cell phone, laptop, desktop,...) that could connect with the website.&nbsp; Pre and post-season soil sampling at 6-inch intervals to 5 feet (or rock) depth along with rain gage data provided directly-measured water budget information. In the third set of equipment, data were downloaded at the field locations for subsequent analysis and use.</p><br /> <p>&nbsp;</p><br /> <p><strong>Kansas - Obj. 1: Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</strong></p><br /> <p>An irrigation scheduling field study concerning usage of crop coefficients based on thermal units was continued at the KSU Northwest Research-Extension Center (NWREC) at Colby, Kansas.&nbsp; The field data for the 2016 season has been collected and will be analyzed during the winter months.&nbsp; A new irrigation scheduling study involving all three scientific based approaches (soil, plant, and weather measurements) was initiated and data was collected in 2016.&nbsp; The data will be analyzed during the winter months.&nbsp; Both studies will be continued in 2016.</p><br /> <p><strong>Obj. 2:&nbsp;&nbsp; Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</strong></p><br /> <p>Two field studies initiated in 2015 at NWREC to evaluate in-season fertigation with macronutrients (N and P) and microelements (primarily Zinc) for field corn production were continued in 2016.&nbsp;&nbsp; In one study, it was shown that spreading the phosphorus application out during the planting through blister kernel period increased corn grain yields by approximately 1.32 Mg/ha.&nbsp; In the other study, there was no advantage of applying phosphorus through SDI fertigation later than blister kernel growth stage in corn.&nbsp; A field study examining precision mobile drip irrigation (PMDI) where driplines are attached to a moving center pivot platform initiated in 2015 at the KSU Southwest Research-Extension Center at Garden City, Kansas was continued in 2016.&nbsp; A study comparing PMDI and SDI for corn production was initiated in 2016 at NWREC.&nbsp; A study at NWREC to evaluate the potential for narrow row spacing of corn when grown with subsurface drip irrigation (SDI) was continued in 2016.&nbsp; This latter study is laying groundwork for future collaboration with Chinese Agricultural University, Beijing China.&nbsp; The field data for the 2016 season for all these studies has been collected and will be analyzed during the winter months.&nbsp; A review of subsurface drip irrigation for 4 crops (tomato, cotton, corn and onion) was published in a refereed journal.&nbsp; A manuscript concerning simplified equations to size SDI flushlines has been accepted for publication in a refereed journal in 2017.&nbsp;</p><br /> <p><strong>Obj. 3: Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</strong></p><br /> <p>Presentations have been made at a regional irrigation meeting and the SWREC Field Day for irrigators and nationally for scientists and engineers at the technical conference of the Irrigation Association.</p><br /> <p>&nbsp;</p><br /> <p><strong>Nebraska - </strong>In 2016, Dr. Irmak installed another SDI system in eastern Nebraska (5 acres) that has 136 plots/valves that are controlled individually. The system manifold is has three mainlines with triple-stack orientation. The research project that was conducted by Dr. Irmak on SDI frequency has been published in Irrigation Science. The objectives of this research were to: (i) to evaluate the effects of subsurface drip irrigation (SDI) amount and frequency on maize production and water use efficiency, (ii) develop production functions and quantify water use efficiency, and (iii) develop and analyze&nbsp; crop yield response factors (Ky) for field maize (<em>Zea mays</em> L.). Five irrigation treatments were imposed: fully-irrigated treatment (FIT), 25% FIT, 50% FIT, 75% FIT, rainfed and an over-irrigation treatment (125% FIT). There was no significant (<em>P </em>&gt; 0.05) difference between irrigation frequencies regarding the maximum grain yield; however, at lower deficit irrigation regime, medium irrigation frequency resulted in lower grain yield. There was a decrease in grain yield with the 125% FIT as compared to the FIT, which had statistically similar yield as 75% FIT. Irrigation rate significantly impacted grain yield in 2005, 2006 and 2007, while irrigation frequency was only significant during the 2005 and 2006 growing seasons (two dry years) and the interacting effect was only significant in the driest year of 2005 (<em>P</em> = 0.006). For the pooled data from 2005 to 2008, irrigation rate was significant (<em>P</em> = 0.001) and irrigation frequency was also significant (<em>P</em> = 0.015), but their interaction was not significant (<em>P</em> = 0.207). Overall, there were no significant differences between irrigation frequencies in terms of grain yield. Ky had interannual variation and average seasonal Ky values were 1.65, 0.91, 0.91 and 0.83 in 2005, 2006, 2007 and 2008, respectively, and the pooled data (2005-2008) Ky value was 1.14.</p><br /> <p><strong>New Mexico - Objective 1: </strong>Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</p><br /> <p>Development and Evaluation of Soil-Based Irrigation Scheduling: We continued to calibrate the soil moisture content sensor to measure the moisture content, soil temperature, and soil salinity for water, solute and energy transport through soil. The Hydra probe are used to schedule irrigation for the growing chile using irrigation with brackish groundwater and RO concentrate in the greenhouse. During 2015, more experiments were conducted using saline water and sensor calibration and irrigation scheduling was done using Hydra sensors.</p><br /> <p><strong>Objective 2: </strong>Develop micro-irrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</p><br /> <p>Greenhouse experiment was conducted to test three chile pepper cultivars growth, physiology and yield irrigated under a water salinity gradient using drip irrigation system. All chile pepper cultivars were salt sensitive and can be irrigated up to 3 dS/m of water.</p><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong>New York - </strong>In 2016 we conducted an irrigation management trial on 3 apple farms (one each in Ulster and Orleans, and Clinton Counties) and 1 at the experimental station in Geneva by using the Cornell Apple irrigation model. Geneva was an Empire/B9 orchard planted in 2011 at 1,156 trees/acre. Hudson (Ulster) was a Gala/M9 orchard, planted in 2011 at 1,117 trees per acre. In 2015, a Plumac/B9 orchard was planted in Orleans, at 1,980 trees/acre. In Champlain valley (Clinton) a NY1/B9 orchard was planted in 2010 at 1,037 trees/acre.</p><br /> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; At each site we managed soil water level according to the irrigation model (Cornell) to minimize water stress while other trees were left unirrigated. We assessed tree growth and tree stress, and crop yield, fruit size and fruit quality (flesh firmness and sugars) with irrigation and no irrigation.</p><br /> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Accumulating the water balance values from bud break gives cumulative water supply and water demand. In 2016 both in Geneva and Hudson, the cumulative graph showed that water requirement exceeded supply from rain from June through October, indicating the need to irrigate the trees during the whole summer (Figure 1).</p><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <p>Figure 1. Cumulative tree transpiration and rainfall from May through October in Geneva and Hudson Valley, NY in 2016.</p><br /> <p>&nbsp;</p><br /> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The growth, function, productivity, and water use of trees are closely tied to tree water status. By the use of a pressure chamber, we can measure the suction force that is being exerted by the tree to get the water. The more negative that value is, the more the tension the tree needs to exert, thus, the more stressed it gets. We can consider that tree stress starts with values below about -1.6 MPa. No tree stress was observed in Geneva in 2015, where no differences were observed between irrigated and non-irrigated trees (Figure 2). On the other hand, even though significant differences were observed in 2016 for Geneva, non-irrigated trees barely reached stress (Figure 2). Significant water stress was observed during all three-summer measurements in 2015 in Hudson for non-irrigated trees, with values lower than -1.6 MPa (Figure 2). In 2016 in Hudson Valley, significant differences were observed between irrigated and non-irrigated trees, but stress was not as important as the previous year (Figure 2).</p><br /> <p>Figure 2. Tree stress during summer in Geneva and Hudson Valley in 2015 and 2016. Asterisks indicate significant differences.</p><br /> <p>&nbsp;</p><br /> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Regarding yield and fruit size, no differences were observed in Geneva for both years (Figure 3), where not much tree stress was observed (Figure 2). Conversely, yield and fruit size in Hudson were significantly much smaller for those non-irrigated trees (Figure 3). Irrigated trees had an average of 1.5 kg more per tree, with bigger apples about 140 g vs 110 g (irrigated &ndash; non irrigated respectively) (Figure 3).</p><br /> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Considering the results from the Hudson orchard on its 5^th leaf, we can estimate a loss of 235 bu/ha (1,117 trees/acre) or 414 bu/ha in case we had a high density orchard as in Orleans (1,980 trees/acre). In terms of crop value, lack of irrigation will infer a loss of 3,859 $/ha &ndash; 6,809 $/ha depending on the tree density. Usually, when the crop is light, there can be some stress with little effect, but when the crop is heavy any stress has a stronger effect. Losses due to water stress could even be worst for full productive orchards and late varieties with a longer growing season such as Fuji.</p><br /> <p>&nbsp;</p><br /> <p>Figure 3. Yield and fruit size in Geneva and Hudson orchards in 2015 and 2016. Asterisks indicate significant differences.</p><br /> <p>&nbsp;</p><br /> <p>Summary. Good water status is essential to maximize fruit size at any given crop load. In our trials, it was seen that in some locations irrigation was not necessary, but at the Hudson location irrigation led to better fruit size and economic value. With more precise water management growers will be able to limit plant water stress and more consistently achieve the optimum economic fruit size and calcium content for each variety. By the use of the updated Apple Irrigation website, growers can easily improve the yield of their orchards by weekly applying the right water amount.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Oklahoma - </strong><span style="text-decoration: underline;">Objective 1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</span></p><br /> <p>Numerous research and extension activities have been conducted at Oklahoma State University during the report period to promote effective irrigation scheduling methods. A recent multi-state (OK, TX, KS) project was initiated on promoting sensor-based technologies to improve irrigation scheduling, using funds provided by the NRCS Conservation Innovation Grant. As part of this project, canopy temperature and soil moisture sensors were installed at two research stations and three demonstration sites under different types of soil, crop, and irrigation systems. Two of these sites had cotton, corn, and sorghum under SDI systems. In addition, two graduate students have been recruited to work on this project, with results expected to be disseminated within the next three years.</p><br /> <p>&nbsp;</p><br /> <p><span style="text-decoration: underline;">Objective 2. Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</span></p><br /> <p>&nbsp;</p><br /> <p>A research project initiated in 2014 at the OSU Panhandle Research and Extension Center near Goodwell, OK on &ldquo;Developing Management Strategies for Subsurface Drip Irrigation in the Oklahoma Panhandle&rdquo; was continued during the 2016 growing season. The objective of this project was to evaluate how crop row placement will influence corn and grain sorghum yield response at irrigation regimes of 50, 75, and 100% of full irrigation. The results from the three years of this project have been disseminated at field days, meetings, and conferences and will be also published in peer-reviewed journals.</p><br /> <p>&nbsp;</p><br /> <p>Another project evaluated the performance of a SDI system that has been used for disposing swine effluent for the past eight years. Several graduate students received hands-on training on evaluating the performance of drip systems and the results were presented at three conferences. A YouTube video was also produced and uploaded on the same topic.</p><br /> <p>&nbsp;</p><br /> <p>A third major project was conducted on modeling salt dynamics and accumulation under SDI systems and different treatments of irrigation water quality. HYDRUS 2D/3D model has been used for modeling. Efforts have been made to improve the accuracy of input data by taking numerous samples for soil salinity and root density from southwest Oklahoma. The results will help producers better manage their SDI systems when marginal-quality water resources are used to meet full or partial crop demand.</p><br /> <p>&nbsp;</p><br /> <p><span style="text-decoration: underline;">Objective 3. Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</span></p><br /> <p>Dissemination of information on adoption of microirrigation systems was accomplished by presenting at numerous field days, meetings, workshops, and in-service trainings.</p><br /> <p>&nbsp;</p><br /> <p><strong>Oklahoma</strong> - <span style="text-decoration: underline;">Output:</span> Presentations were given on topics related to the project objectives at 16 conferences, workshops, and field days, reaching a total of 361 contact hours. A YouTube video was produced on evaluating the performance of SDI systems: <a href="https://youtu.be/CqGp5Eug9eg">https://youtu.be/CqGp5Eug9eg</a></p><br /> <p>&nbsp;</p><br /> <p><strong>Oregon - </strong><strong>Objective One: Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</strong></p><br /> <ol><br /> <li><span style="text-decoration: underline;">Vineyards</span></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>In OR, WA, and CA soil-based drip irrigation scheduling is being combined with weather-based drip irrigation scheduling to optimize the yield and quality of vineyard production and financial return in cooperation with SmartVineyards.&nbsp; Ground truth of plant water potential is also being measured.&nbsp; Early during the growing season there are risks of wasting water and nutrients from over irrigation when the flush of early annual vine growth can be favored by minimal or very low levels of water stress.&nbsp; Later in the season, the relative amount of water stress that is most beneficial for the final product increases with the grape development stage.&nbsp; The ideal amount and timing (trajectory) of water stress (as measured by soil, plant, or weather data) will vary with cultivar, weather, and site.&nbsp; In Oregon we are trying to understand the optimal trajectory of stress over time as measured in the soil, the environment, or plant.&nbsp; We seek to measure the trajectory of stress.&nbsp; Modification of the stress trajectory holds the promise of better water use efficiency, protection of water quality, optimization of product quality, and the realization of providing a better return on vineyard investment.&nbsp; The approach is to collect and evaluate automated data that is interpreted and provided in real time to growers.</p><br /> <ol><br /> <li><span style="text-decoration: underline;">Automation of data collection and delivery</span></li><br /> </ol><br /> <p>The approach taken for vineyards (above) is being tested on a smaller scale with several other crops.</p><br /> <ol><br /> <li><span style="text-decoration: underline;">Seed production of native plants</span></li><br /> </ol><br /> <p>In Oregon fixed irrigation schedules are being compared to soil- and weather-based scheduling for seed production from native plants.&nbsp; Plant species required 0 to 200 mm of supplemental irrigation per year to maximize seed yield.&nbsp; For a given species, yield responses to irrigation varied substantially by year.&nbsp; We have determined that accounting for rainfall during and prior to seed production improves the accuracy of estimating the amount of irrigation required.&nbsp; Species differ in the preceding time interval where precipitation needs to be counted against the irrigation requirement.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><span style="text-decoration: underline;">Stevia </span></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>Although drip irrigation has been used for the production of <em>Stevia rebaudiana</em>, few people have determined the best irrigation criteria in terms of soil water tension or crop evapotranspiration.&nbsp; Stevia leaf production was tested using irrigation onset criteria to trigger irrigation at different levels of soil water tension.&nbsp; Equivalent levels of crop evapotranspiration were calculated and they were compared to reference evapotranspiration.&nbsp; Leaf yield and steviol glycoside content were greatest with irrigation onset criteria at very low levels of soil water tension (10-20 kPa).&nbsp; When correcting for crop canopy cover, leaf yield and steviol glycoside content were greatest when water application was similar to reference evapotranspiration.</p><br /> <p>&nbsp;</p><br /> <p><strong>Objective Two: Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</strong></p><br /> <ol><br /> <li><span style="text-decoration: underline;">Protection of fresh produce from human pathogens in irrigation water</span></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>Many fresh fruit and vegetables grown with drip irrigation are commonly consumed raw; therefore, they are subject to the FDA&rsquo;s provisions of the Food Safety Modernization Act.&nbsp; A major portion of the Produce Rule focuses on the microbiological quality of irrigation water used in the production of raw vegetable products.&nbsp; We conducted multi-year studies on the effect of contaminated irrigation water applied via furrow or drip irrigation on the relative fate of generic <em>E. coli</em> in water, in soil, and on onions during growth, curing, harvesting, and storage.&nbsp;</p><br /> <p>&nbsp;</p><br /> <p>It is very important to have in irrigation practices to this food safety modernization act in order to use your vacation effectively for the production of fresh vegetables for the production of fresh produce. We study actual movement and the soil from water that exited drip tape. The water source is highly contaminated with <em>E. <strong>coli</strong></em>. We found that the actually bacteria stated in the soil to the water entered soil did not move appreciably towards the onion bulbs. Furthermore the back trio did survive long in the soil bacteria did not survive long in the soil or on the surface the bulbs.</p><br /> <p>&nbsp;</p><br /> <p>Irrigation with contaminated irrigation water. We tested traces of chlorine dioxide as a possible means to lower the bacterial contamination of water used for the production of fresh produce.</p><br /> <ol><br /> <li>Current subsurface drip or furrow irrigation practices do not appear to pose a significant risk for <em>E. coli</em> contamination of dry bulb onion grown on silt loam in the Treasure Valley, in part because most of the <em>E. coli</em> load in contaminated water remained close to where water entered into the soil (i.e., edges of furrows or drip tape).</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol><br /> <li><em>E. coli</em> had rapid die-off both in the soil and on onion exteriors in the field.&nbsp;</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol><br /> <li>Onions from these drip and furrow irrigation trials that were stored in sterilized plastic containers or old wooden bins largely had no detectable <em>E. coli</em> on the bulb exteriors at the time of pack-out. There were isolated cases of <em>E. coli </em>detection on bulb exteriors but these few cases were not correlated with storage container type or irrigation water source. No <em>E. coli </em>was detected in the interior of any onion bulbs. Therefore, plastic containers do not provide added food safety value compared with wooden boxes for the storage of dry bulb onions.&nbsp;</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol><br /> <li>The use of chlorine dioxide in drip irrigation systems shows promise as a means to remediate microbial contamination of irrigation water, if needed for compliance with water quality standards.&nbsp; The use of 1 and 3 ppm chlorine dioxide resulted in substantial reductions in <em>E. coli </em>in irrigation water clear to the end of the drip tape.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><span style="text-decoration: underline;">Fertigation</span></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>Nutrient application strategies for drip-irrigated onion was studied. Phosphorus can be a limiting factor in production.&nbsp; High soil pH, and cold soil complicate phosphorus availability. Supplemental phosphorus through the drip system was compared with phosphorus applied for planning.&nbsp; Various plant and soil sampling strategies were compared for fertigation guidelines.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><span style="text-decoration: underline;">Delivery of herbicides</span></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>Herbicides were applied through the drip irrigation system in the hopes of achieving better control of yellow nutsedge. Outlook herbicide applied through drip irrigation was successful in helping to control yellow nutsedge.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><span style="text-decoration: underline;">Delivery of fungicides</span></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>Fungicides were applied through the drip system in order to try to obtain better control of root fungi.&nbsp; Pink root and plate rot were not significant problems in the onion fields used for the trials and the products tested were not beneficial.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><span style="text-decoration: underline;">Adaptation of drip irrigation for potato production</span></li><br /> </ol><br /> <p><span style="text-decoration: underline;">&nbsp;</span></p><br /> <p>Potato production is generally conducted with sprinkler irrigation.&nbsp; In the US drip irrigation has not been cost effective in comparison to sprinkler irrigation. We sought to change the drip irrigation configuration so that the drip irrigation system could be more efficiently utilized. Rows of potato plants were moved so that two rows of plants could be irrigated with a single drip tape.&nbsp; In this way only half the length of tape would be needed to grow a potato crop.&nbsp; Currently sprinkler irrigation is used in part to cool the environment.&nbsp; In order to try to cool the environment of the developing potato tubers, we tested production with potatoes planted into flat beds.&nbsp; Double rows of plants with drip tapes 72 inches apart used less drip tape and water in 2016 while retaining acceptable yield.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Objective 3: Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</strong></p><br /> <p>In objective 1 above, the automatic collection, evaluation, and deliver of soil and weather data is described.&nbsp; The goal is to interpret and deliver results, predictions, and projections in real time to growers&rsquo; smart phones and laptops based on growers&rsquo; demands.&nbsp; Growers are gaining real time access to information from their fields for water management decision making.&nbsp; These emerging tools and technology for growers have the potential to simultaneously optimize economic outcomes and minimize the losses of water and nutrients.</p><br /> <p>&nbsp;</p><br /> <p><strong>Oregon - Outcomes or Projected Impacts (from the project proposal)</strong></p><br /> <ul><br /> <li>Soil-, weather-, and plant-based or combined microirrigation scheduling approaches will provide valuable choices for a diverse clientele of growers to improve their crop production and profitability while reducing irrigation withdrawals.</li><br /> <li>Increased adoption and proficient management of microirrigation scheduling by growers will improve water productivity and promote improved water quality over a wider range of end-user characteristics and constraints.</li><br /> <li>Risks of negative impacts to environment, soil, and water quality that affect all of society will be minimized through reduced leaching or other off-site /non-target chemical movement possibly opening up previously non-productive lands to microirrigation.</li><br /> <li>Benefits of microirrigation to growers will be more fully realized through application of improved fertigation practices that will better match fertilizer applications (rates, timing, placement and formulations) to crop requirements.</li><br /> <li>Conceptualization and generalization of microirrigation design and management procedures and tools will allow for growers, technical service providers, dealers, and industry to communicate more easily the requirements and preferences for new system installations.</li><br /> <li>Improved design and management procedures for SDI will allow broader penetration of microirrigation into regions of the country where adoption has been limited.</li><br /> <li>Comparisons of alternative irrigation systems will allow growers to make the best system choice for their operations and will allow them to optimize performance of existing systems.</li><br /> <li>Internet-based decision tools and apps (for smartphones, tablets, etc.) will provide convenient, easily updated, and audience-tailored content to help end-users improve irrigation scheduling, water and nutrient management, and system design.</li><br /> <li>Expansion of existing websites and accessibility of publications will allow for increased regional, national and international adoption of microirrigation technology.</li><br /> <li>Educational events tailored to the audience abilities and needs will increase adoption and correct usage of microirrigation.</li><br /> <li>Technical sessions and/or conferences will bring together experts representing different approaches to microirrigation; expand the knowledge base; improve networking of scientists and contribute to a more integrated approach to this field of research and education.</li><br /> </ul><br /> <ul><br /> <li>Increased collaboration between public and private entities will help to increase adoption of microirrigation on a much broader scale and will improve the correct implementation of this technology.</li><br /> </ul><br /> <p>&nbsp;</p><br /> <p><strong>Texas - </strong>Objective 1: Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</p><br /> <p>&nbsp;</p><br /> <p>Accomplishments: Grain sorghum and corn were produced with subsurface drip irrigation (SDI) at the USDA-ARS laboratory in Bushland, Texas in 2015 and 2016, respectively, in two 4.7-ha fields containing large weighing lysimeters. Two additional 4.7-ha fields containing large weighing lysimeters were located adjacent to the SDI fields; these were planted and managed in nearly the same way as the SDI fields (crops, agronomy, and tillage) except irrigation was by sprinkler. For the two SDI fields and one sprinkler field, irrigations were scheduled to replace full crop evapotranspiration (ET) in 20-mm increments; in the second sprinkler field, irrigations were applied at 75% crop ET. Crop ET was measured by the lysimeters and estimated by neutron probe using a soil water balance (where probe access tubes were located both in the lysimeters and in the surrounding fields. In-situ soil temperature, in-situ soil heat flux, radiometric soil and canopy temperature, and micrometeorological variables were measured at each lysimeter. Although irrigations were scheduled by soil-based methods, the additional radiometric temperature and micrometeorological measurements will be used to further develop mass and energy balance models for crops grown under sprinkler and SDI; these models will have direct application in plant- and weather-based irrigation scheduling methods.</p><br /> <p>&nbsp;</p><br /> <p>Objective 2: Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</p><br /> <p>&nbsp;</p><br /> <p>Accomplishments: The two SDI fields described in Objective 1 were based on designs and management practices developed from previous research at USDA-ARS, Bushland, Texas and partners at Texas A&amp;M AgriLife Research and Extension. The SDI lateral depths were buried and maintained at ~0.22 m below the soil surface and spaced at 1.52 m. Crops were flat-planted in rows spaced 0.76 m, resulting in SDI laterals being located in alternate interrows. Furrow dikes were installed in each interrow following crop establishment to control run on and run off of surface water. Following crop harvest in 2015, crop residue was left on the surface during the winter, but shredded and incorporated into the soil in time for planting in 2016. However, crop residue left on the soil surface results in more favorable rodent habitat; the SDI laterals suffered extensive rodent damage, requiring an inordinate amount of labor for repairs. Therefore, crop residue will be incorporated into the soil earlier to discourage rodents, but recognizing that this carries a significant caveat. The Pullman clay loam and other soils prevalent in our region are prone to crusting following even light wetting events, and crusting of bare soil results in much greater wind erosion potential, which is a very serious concern during high wind periods typical in the spring season. For bare soil, diligence is then required to roughen the soil surface following crusting, which is effective in reducing wind erosion at our location.</p><br /> <p>&nbsp;</p><br /> <p>Objective 3: Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</p><br /> <p>&nbsp;</p><br /> <p>Accomplishments: Early season soil water evaporation losses (i.e., during sparse canopy cover) were up to 40% less for SDI compared with sprinkler, as measured by the weighing lysimeters. More detailed measurements of soil water evaporation using microlysimeters are currently under analysis. Although crop ET was sometimes larger for SDI compared with sprinkler later in the season when plants were fully developed, SDI resulted in greater seasonal crop water productivity. These results will be disseminated to university partners to develop extension publications, and presented at producer-oriented conferences, workshops, seminars, and field days.</p><br /> <p>&nbsp;</p><br /> <p><strong>Virgin Islands - Greenhouse production of slicing cucumbers in the U.S. Virgin Islands </strong><strong>(1^st crop cycle)</strong></p><br /> <p>Cucumber is one of the major vegetables in greenhouse production. Little information is available regarding the cultivation of cucumbers in closed environment in the U.S. Virgin Islands. Our study evaluated the production of slicing cucumbers in greenhouse under different substrate volumetric water contents (VWC) applied using low-cost open-source microcontrollers. We tested four cucumber varieties (&lsquo;Boa&rsquo;, &lsquo;Bomber, &lsquo;Corinto&rsquo; and &lsquo;Summer Dance&rsquo;) and three substrate VWCs to trigger irrigation (0.24, 0.36 and 0.48 m³/m³), on a split-plot CRD and three replications. Plants were transplanted into 9.45-L pots with Pro-Mix BX Mycorrhizae: perlite substrate (70%: 30%), trained on a vertical plastic line, and fertigated with calcium nitrate (150 and 140 mg/L Ca and N) and 10-30-20 peat-lite plant starter fertilizer (30 mg/L N). We assembled two independent and fully automated irrigation systems using a Mega 2560 board (Arduino), a logging shield (Adafruit), eighteen 10HS soil moisture sensors (Decagon), three 5-VDC 8-module relay drivers (SainSmart) and eighteen 24-VAC 2.54-cm solenoid valves (RainBird) connected to a 12/24-VDC 500-VA 31EJ02 transformer (Dayton). The power line was protected with a 3400-J 51110-SRG surge protector (Leviton). The system was powered using a 20-W Infinium solar panel (ML Solar) connected to a 12/24-VDC 10-A 1210RN solar charge controller (EPSolar) and two 12-VDC 7.2-Ah rechargeable batteries (Yuasa). Irrigation was installed using a manifold built with 2.54-cm PVC pipes, one solenoid valve and 1.9-cm polyethylene tubing with 4-L/h drip emitters connected to one O-ring tubing per plant. When the soil VWC dropped below the thresholds, irrigation was turned on for 1 min. The soil moisture sensors malfunctioned due to a defective internal part, not controlling the irrigation properly. Irrigation was controlled manually every other day. The three VWC treatments were averaged, resulting in nine replications per variety. &lsquo;Corinto&rsquo; (22,436) and &lsquo;Boa&rsquo; (20,000 kg/ha) total yield were higher than &lsquo;Summer Dance&rsquo; (10,604) and &lsquo;Mountie&rsquo; (10,435 kg/ha) (p=0.0001). Marketable yield was respectively 85%, 91%, 63% and 40% of the total yield (p&lt;0.0001). Total number of fruits per plant were 9.6 for &lsquo;Corinto&rsquo;, 7.1 for &rsquo;Boa&rsquo;, 4.7 for &lsquo;Mountie&rsquo; and 3.8 for &lsquo;Summer Dance&rsquo; (p&lt;0.0001). Fruit width, hardness and sugar content were not significantly different (p&gt;0.05). Fruits were shorter on &lsquo;Boa&rsquo; (18.7) and &lsquo;Corinto&rsquo; (19.7 cm) compared to &lsquo;Mountie&rsquo; (24.2) and &lsquo;Summer Dance&rsquo; (25.7 cm) (p=0.0180). Based on our results, fully functional sensors are necessary to control irrigation properly. &lsquo;Corinto&rsquo; and &lsquo;Boa&rsquo; are the recommended varieties for greenhouse cultivation in the U.S. Virgin Islands.</p><br /> <p>&nbsp;</p><br /> <p><strong>Mulching strategies using conservation tillage for weed management in tropical organic hot pepper cropping systems</strong></p><br /> <p>Soil conservation and effective weed management are generally conflicting objectives in tropical organic cropping systems where tillage is the primary means for weed suppression. Cover crops, conservation tillage, and mulching are known practices that provide numerous ecosystem services, but are seldom incorporated together into an integrated cropping system plan. The primary objective of this research is to evaluate a holistic approach to soil conservation that provides weed suppression in tropical organic cropping systems. Experiments were conducted at the Agricultural Experiment Station on St. Croix, USVI in 2015 and 2016 at two independent field sites. Trials began with the establishment of sunn hemp (<em>Crotalaria juncea&nbsp;</em>L.) in all experimental areas on October 16, 2015 and terminated on January 11, 2016. Four treatments were arranged in a RCBD split with two weed removal frequencies (1 and 3 weeks), and replicated three times. Treatments included: 1) sunn hemp mulch (SHM), 2) sunn hemp mulch plus hay (SHM+hay), 3) sunn hemp mulch plus black landscape fabric (SHM+fabric) and 4) sunn hemp mowed and incorporated that served as a check plot (SH+none). Sunn hemp mulch was generated using a no-till roller-crimper. Peppers (<em>Capsicum annum&nbsp;</em>L.) were transplanted into treatments on January 14, 2016. Following treatment establishment, irrigation was performed using weather-based evapotranspiration calculations and fertigation was used in accordance with best management practice recommendations. Above-ground biomass of sunn hemp at termination did not differ between fields; and measured 3,717 kg ha^-1&nbsp;in field 1 and 4,367 kg ha^-1&nbsp;in field 2. In-bed weed suppression at three weeks after pepper transplant (WAT) was greatest for SHM+fabric, followed by SHM+hay, and lowest for SHM and SH+none treatments. At six WAT, SHM+fabric provided the greatest weed suppression with similar results for the remaining three treatments in field 1. In Field 2, SHM+fabric suppressed weeds as well as SH+none and SHM+hay. A similar trend was observed at nine WAT for both fields as described for field 1. Low frequency weeding at three-week intervals was generally as effective as weekly weed removal resulting in similar pepper yields. Overall, the SHM+fabric and SHM+hay treatments had the greatest Jalapeno yields with no differences between the SHM and SH+none treatments. Serrano pepper yields were greatest in the SHM+fabric, SHM+hay, and SH+none treatments; with the lowest yields recorded in the SHM treatment. Results indicate that soil conservation need not be compromised at the expense of weed suppression through the implementation of integrated mulching strategies.</p><br /> <p>&nbsp;</p><br /> <p><strong>Washington State - Obj. 1: Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</strong></p><br /> <p>Three field research locations are being used to collect data from treatments intended to quantify potential to sustain fruit production in vineyards during future periods of low water availability in the Yakima Valley of Washington State. This area is primarily, if not wholly dependent, on irrigation water released from winter snowpack in the Cascade Mountain range. Two of these field locations are cited in commercial wine grape vineyards with grower/producer cooperators and activities are guided by an industry advisory committee that meets quarterly with the research team conducting these experiments. Treatments involve the application of season-long deficit irrigation by deep subsurface micro-irrigation and at rates equivalent to 60, 30, and 15 percent of the commercial irrigation rate. Plant water stress was measured a selected dates during the 2016 growing season using on-plant measurements by the pressure bomb technique and compared with remote sensing images using near-IR and multi-spectral cameras.&nbsp; Another experiment is using similar treatments and methods to determine impacts of these techniques in a Concord grape vineyard located at the WSU Irrigated Agriculture Research and Extension Center near Prosser. The fourth field experiment is located within a commercial wine grape vineyard near Benton City and is contrasting water loss from a vineyard using an Eddy Covariance flux station with the estimated ET loss and recommended water replacement using the FAO P-M method. These data are currently being reduced and analyzed after completion of the 2016 growing season. Additionally, both fruit quantity and quality measurements are being analyzed to determine water: fruit production efficiency for future recommendations to growers in this region.</p><br /> <p>&nbsp;</p><br /> <p><strong>Obj. 2:&nbsp;&nbsp; Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</strong></p><br /> <p><strong>&nbsp;</strong></p><br /> <p>Our hypothesis is that subsurface irrigation applied directly into the vine&rsquo;s lower root-zone can result in both greater water use efficiency and improved fruit quality over surface applied drip irrigation. A randomized complete block design with three replications of each treatment and a split plot design to compare pulse and continuous irrigation schedules were used with season-long deficit irrigation treatments at Kiona Vineyards in the Red Mountain AVA of Washington. During 2015-2016, over 800 vines received subsurface drip irrigation applied by direct root-zone (DRZ) delivery at depths of 1, 2 or 3 feet below ground via vertically installed hard plastic tubes. Subsurface irrigation was delivered as either continuous or pulsed application and compared to surface drip irrigation application on an additional 180 vines managed to meet commercial production and quality goals.</p><br /> <p>&nbsp;</p><br /> <p><strong>Obj. 3: Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</strong></p><br /> <p>&nbsp;</p><br /> <p>Our lab group is developing a web-site <a href="https://labs.wsu.edu/jacoby/">https://labs.wsu.edu/jacoby/</a>&nbsp; inform our grower audience about our most current research activities and findings.&nbsp; Additionally, we participate in field days to engage growers with on-site applied research each growing season, present posters and oral reports of our research at annual grower meetings such as the Washington Winegrowers and the Washington Grape Society, as well as national meetings such as the Irrigation Association and American Society of Enology and Viticulture. We also prepare new articles for the popular press and work closely with reporters with local and area media outlets. The project PI and a colleague presented a webinar sponsored by Decagon Devices on the topic <em>Growing Wine Grapes with Less Water </em>which featured subsurface micro-irrigation technology developed through our applied research program.</p>

Publications

<p>Kisekka, I., G. Nguyen, J. Aguilar and Danny Rogers. 2016. Mobile Drip Irrigation Evaluation in Corn. Kansas Agricultural Experiment Station Research Reports: Vol. 2: Iss. 7. http://dx.doi.org/10.4148/2378-5977.1253.</p><br /> <p>Lamm, F. R.&nbsp; 2016.&nbsp; Cotton, Tomato, Corn, and Onion Production with Subsurface Drip Irrigation - A Review.&nbsp; Trans. ASABE Vol. 59(1):263-278.&nbsp;&nbsp;</p><br /> <p>Lamm, F. R. and J. Puig-Bargu&eacute;s.&nbsp; 2017.&nbsp; Simple equations to estimate flushline diameter for subsurface drip irrigation systems. Trans. ASABE (in press)</p><br /> <p>Lamm, F. R., D. H. Rogers, and M. T. Jablonka.&nbsp; 2016.&nbsp; Long term performance of a research subsurface drip irrigation system.&nbsp; ASABE Paper no. 162461575.&nbsp; Available from ASABE, St. Joseph, MI.&nbsp; 15 pp.</p><br /> <p>Lamm, F. R., D. H. Rogers, I. Kisekka, and J. P. Aguilar.&nbsp; 2016.&nbsp; Longevity: An important aspect in SDI success.&nbsp; In: Proc. 28th annual Central Plains Irrigation Conference, Feb. 23-24, 2016, Kearney, Nebraska.&nbsp; Available from CPIA, 760 N. Thompson, Colby, Kansas.&nbsp; pp. 19-28.</p><br /> <p>Lamm, F. R., D. M. O&rsquo;Brien, and D. H. Rogers.&nbsp; 2016.&nbsp; Using the K-State center pivot sprinkler and SDI economic comparison spreadsheet &ndash; 2016.&nbsp; In: Proc. 28th annual Central Plains Irrigation Conference, Feb. 23-24, 2016, Kearney, Nebraska.&nbsp; Available from CPIA, 760 N. Thompson, Colby, Kansas.&nbsp; pp. 29-37.</p><br /> <p>Lamm, F. R., K. C. Stone, M. D. Dukes, T. A. Howell, Sr., J. W. D. Robbins, Jr., and B. Q. Mecham.&nbsp; 2016.&nbsp; Emerging technologies for sustainable irrigation: Selected papers from the 2015 ASABE and IA irrigation symposium.&nbsp; Trans. ASABE Vol. 59(1):155-161.</p><br /> <p>Oker, T.E., Nguyen, G.H.T., Kisekka, I., Aguilar, J., Danny, R., 2016.&nbsp; Assessment of Mobile Drip Irrigation in Corn: 2016 ASABE Annual International Meeting; Poster #62; Paper #162460433. ASABE, Orlando, FL.</p><br /> <p>Irmak, S., K. Djaman and D.R. Rudnick. 2016. Effect of full and limited irrigation rate and frequency on subsurface drip-irrigated maize evapotranspiration, yield, water use efficiency and yield response factors. <em>Irrigation Science</em> 34(4): 271-286. doi10.1007/s00271-016-0502-z.</p><br /> <p>Baath G. S., M. K. Shukla, P. W. Bosland, R. L. Steiner, and S. J. Walker. 2017. Irrigation Water Salinity Influences at Various Growth Stages of <em>Capsicum annuum</em>. Ag Water Management. 179: 246-253.</p><br /> <p>Sharma P., M.K. Shukla, P. Bosland and R. Steiner. 2017. Soil moisture sensor calibration, actual evapotranspiration and crop coefficients for deficit irrigated greenhouse chile. Ag Wat Manag. 179: 81-91.</p><br /> <p>Parris, C.A., C.C. Shock, and M. Qian. 2016. Soil water tension irrigation criteria affects <em>Stevia rebaudiana</em> leaf yield and leaf steviol glycoside composition. HortSci. In press.</p><br /> <p>Shock, C.C., E.B.G. Feibert, A. Rivera, L.D. Saunders, N.L. Shaw and F.F. Kilkenny. 2016. Irrigation requirements for seed production of five <em>Lomatium </em>species in a semi-arid environment. HortSci. HortSci. 51:1270-1277.</p><br /> <p>Shock, C.C., S.R. Reitz, R.A. Roncarati, H. Kreeft, B.M. Shock, and J. Klauzer. 2016</p><br /> <p>Drip vs furrow irrigation in the delivery of <em>Escherichia coli</em> to onions. Applied Engineering in Agriculture.&nbsp;32(2): 235-244.</p><br /> <p>Shock, C.C., A.B. Pereira, E.B.G. Feibert, C.A. Shock, A.I. Akin, L.A. Unlenen. 2016. Field comparison of soil moisture sensing using neutron thermalization, frequency domain, tensiometer, and granular matrix sensor devices: relevance to precision irrigation. Journal of Water Resource and Protection, 8:154-167. <a href="http://dx.doi.org/10.4236/jwarp.2016.82013">http://dx.doi.org/10.4236/jwarp.2016.82013</a></p><br /> <p>Yang, K., F.X. Wang, C.C. Shock, S. Kang, Z. Huo, N. Song, D. Maa. 2016. Potato performance as influenced by the proportion of wetted soil volume and nitrogen under drip irrigation with plastic mulch. Agricultural Water Management.&nbsp; Available on line 2 May. <a href="http://www.sciencedirect.com/science/article/pii/S0378377416301317">http://www.sciencedirect.com/science/article/pii/S0378377416301317</a></p><br /> <p>Liu, Z., H. Chen, Z. Huo, F.X. Wang, C.C. Shock. 2016. Analysis of the contribution of groundwater to evapotranspiration in an arid irrigation district with shallow water table. Agricultural Water Management 171:131&ndash;141.</p><br /> <p>Zhang, Y-L., F-X. Wang, C.C. Shock, K-J. Yang, S-Z. Kang, J-T. Qin, and S-E. Li (2017). Influence of different plastic film mulches and wetted soil percentages on potato grown under drip irrigation. Agricultural Water Management. 180:160&ndash;171.</p><br /> <p>Evett, S.R., T.A. Howell, Sr., A.D. Schneider, K.S. Copeland, D.A. Dusek, D.K. Brauer, J.A. Tolk, G.W. Marek, T.M. Marek, and P.H. Gowda. 2016a. The Bushland weighing lysimeters: A quarter century of crop ET investigations to advance sustainable irrigation. Trans. ASABE. 59:163-179.</p><br /> <p>Evett, S.R., D.K. Brauer, P.D. Colaizzi, J.A. Tolk, G.W. Marek, S.A. O&rsquo;Shaughnessy. 2016b. Corn and sorghum performance as affected by irrigation application method: SDI versus mid-elevation spray irrigation. Agric. Water Manage. (in review).</p><br /> <p><span style="text-decoration: underline;">FERRAREZI, R.S.</span>; WEISS, S.A.; GEIGER, T.C.; BEAMER, K.P. 2016. Edible-pod peas as high-value crops in the U.S. Virgin Islands. HortTechnology 26(4). In press.</p><br /> <p>KANG, J.-G.; <span style="text-decoration: underline;">FERRAREZI, R.S.</span>; DOVE, S.K; WEAVER, G.M.; VAN IERSEL, M.W. 2016. Increased fertilizer levels do not prevent ABA-induced chlorosis in pansy. HortTechnology 26(5). In press.</p><br /> <p><span style="text-decoration: underline;">FERRAREZI, R.S.</span>; FERREIRA FILHO, A.C.; TESTEZLAF, R.<span style="text-decoration: underline;"> 2016. </span>The substrate moisture retention in subirrigation is influenced by the water height and irrigation time. Horticultura Brasileira 34(4). In press. (in Portuguese)</p><br /> <p>SALVADOR, C.A.; <span style="text-decoration: underline;">FERRAREZI, R.S.;</span> BARRETO, C.V.G.; TESTEZLAF, R. 2016. Method to evaluate the efficiency of manual overhead irrigation in citrus rootstock liner production. Engenharia Agr&iacute;cola 36(4). In press.</p><br /> <p>VAN IERSEL, M.W.; WEAVER, G.M.; MARTIN, M.T.; <span style="text-decoration: underline;">FERRAREZI, R.S.</span>; MATTOS, E.; HAIDEKKER, M. 2016. A chlorophyll fluorescence-based biofeedback system to control photosynthetic lighting in controlled environment agriculture. Journal of the American Society for Horticultural Science 141(2): 169-176. URL: <a href="http://journal.ashspublications.org/content/141/2/169.full.pdf+html">http://journal.ashspublications.org/content/141/2/169.full.pdf+html</a>.</p><br /> <p><span style="text-decoration: underline;">FERRAREZI, R.S.</span>; VAN IERSEL, M.W.; TESTEZLAF, R.<span style="text-decoration: underline;"> 2016. </span>Plant growth response of subirrigated salvia &lsquo;Vista Red&rsquo; to increasing water levels at two substrates. Horticultura Brasileira 34(2): 202-209. DOI: <a href="http://dx.doi.org/10.1590/S0102-053620160000200009">http://dx.doi.org/10.1590/S0102-053620160000200009</a>.</p><br /> <p><span style="text-decoration: underline;">FERRAREZI, R.S.</span>; TESTEZLAF, R. 2016. Performance of wick irrigation system using self-compensating benches with substrates for lettuce production. Journal of Plant Nutrition 39(1): 150-164. DOI: <a href="http://dx.doi.org/10.1080/01904167.2014.983127">http://dx.doi.org/10.1080/01904167.2014.983127</a>.</p><br /> <p><span style="text-decoration: underline;">FERRAREZI, R.S.</span>; VAN IERSEL, M.W.; TESTEZLAF, R. 2015. Use of subirrigation for water stress imposition in a semi-continuous CO₂-exchange system. Ornamental Horticulture 21(2): 235-242. DOI: <a href="http://dx.doi.org/10.14295/aohl.v21i2.699">http://dx.doi.org/10.14295/aohl.v21i2.699</a> (in Portuguese).</p><br /> <p>Jacoby, P.W<strong>.</strong>, X.C. Ma, and J.R. Thompson. 2016. Effects of root-zone micro-irrigation on Cabernet Sauvignon. <em>Proceedings: </em>Technical Education Conference on Use of Micro-irrigation in Agricultural Cropping Systems, Irrigation Association Annual Meeting. (full-length paper and oral presentation). December 5-9, 2016. Las Vegas, NV</p><br /> <p>Zuniga, C.E., L.R. Khot, P.W. Jacoby, and S. Sankaran. 2016. Remote sensing based water-use efficiency evaluation in sub-surface irrigated wine grape vines. Proc. SPIE 9866, Autonomous Air and Ground Sensing Systems for Agricultural Optimization and Phenotyping. <a href="http://dx.dpi.org/10.1117/12.2228791/">http://dx.dpi.org/10.1117/12.2228791/</a>.</p><br /> <p>Ma, X.C., P.W. Jacoby, and J.R. Thompson. 2016. Assessing impacts of direct root-zone</p><br /> <p>Irrigation on grapevine physiology. <em>In: </em>Program and Technical Abstracts, Ann. Meeting, ASA-CSSA-SSSA. Nov. 7-11. Phoenix, AZ (3^rd place award &ndash; graduate poster category)</p><br /> <p>Jacoby, P.W.<strong>, </strong>S.H. Sadeghi, J.R. Thompson, Z.B. York, and X.C. Ma. 2016. Influence of direct root-zone micro-irrigation on production of Cabernet Sauvignon in the Pacific Northwest. <em>In:</em></p><br /> <p>Program and Technical Abstracts, p. 97. June 27-30. Monterey, CA</p><br /> <p>Jacoby, P.W.<strong>, </strong>S.H. Sadeghi, J.R. Thompson, Z.B. York, and X.C. Ma. 2016. Influence of direct root-zone micro-irrigation on production of Cabernet Sauvignon. <em>In: </em>Poster Abstracts &ndash; Ann. Meeting, WA Assn. Wine Grape Growers, pp. 20-21. Feb. 9-11. Kennewick, WA</p>

Impact Statements

1. Texas - Continued adoption of SDI in the US Great Plains and other water-limited regions will increase crop water productivity primarily by reducing soil water evaporative losses, and in many cases increasing the quantity and quality of crop produced. Increases in crop water productivity will maintain farm profitability while prolonging water resources, and enhance resiliency to climate change.

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Report Information

Participants

Brief Summary of Minutes

• Ripendra Awal a Water Scientist/Civil Engineer with Prairie View University, TX, was elected 2018 Secretary for the W3128 group. Dr. Rhuanito Ferrarezi and Dr. Davie Kadyampakeni become 2018 Chair and Vice Chair respectively.

 

• Place for next meeting in 2018 was chosen to coincide with the Irrigation Association Show on the dates of Dec. 3-7, Long Beach, CA.

 

• Steve Loring mentioned that W3128 project expires on September 30, 2019. Thus, there is need for a new proposal submission before current project ends. Dr. Loring suggested the need for zoom meeting in winter 2018 (Jan 2018) and that a lead person (s) should be nominated for the proposal development. Dr. Loring further indicated that he would coordinate the efforts to call for the meeting. In the group discussion regarding the proposal development, the following objectives or areas of focus were mentioned to be considered for 2019 going forward:

1) Map ET across the US

2) Assessing water reuse and alternative sources of irrigation water/use of low quality water sources.

3) Assess barriers to adoption and managing of microirrigation using plant-based technologies (Ken Shackel will send out email, and solicit volunteers).

4) Fertigation/chemigation (Freddie Lamm led this discussion)

5) Irrigation management

6) Irrigation management: technology transfer to farmers and fertigation

 

Current objectives of the W3128 project include:

1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.


2. Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.


3. Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.

Discussion on whether a virtual or face-to-face meeting is important to ensure we finalize the proposal by Winter or Spring 2018.

 

• Bradley Rein provided NIFA perspective and overview regarding the Water for Food Production Systems (WfPS) where $32 million will be awarded to successful multidisciplinary, multi-institutional proposals out of 88 applications. Dr. Rein call for individuals interested in reviewing grant proposals to send him an email, if they are not on an application. He also mentioned that there are RFA with Foundation proposals, and other programs such as: Applied research and extension, CARE program (short term, 3-year grants, up to $300,000-500,000).


• Water and Energy Conservation Award, nationally, was accepted by Dr. Steve Loring on Thursday Nov. 10, 2017 from Irrigation Association.


• State reports were presented from Kansas, Florida, California, Texas, Oregon, and Ohio. Members noted the low turnout for the meetings. Steve Loring would contact Directors of Experiment Stations and find out why some members do not participate in the annual meetings.


• Field Tours

The participants of the annual meeting visited 2 sites on Monday, Nov. 6, 2017 at EPCOT site and at a reclaimed water irrigation facility Conserv II site in Orlando.

Accomplishments

<p><strong>Florida</strong></p><br /> <p><strong>Florida </strong></p><br /> <p>The Citrus App requires information on tree spacing (in row and between rows), soil water holding capacity, irrigation system output, and ET source. Water balance estimated using day of year and phenology-based Kc to estimate irrigation quantity and frequency requirements. Evaluation was conducted at three commercial citrus orchards in central and south Florida. The experiment was arranged in a randomized complete block design with four replications at each location. Three irrigation scheduling treatments for conventional irrigation were as follows: 1) Citrus App, 2) Grower determined irrigation, 3) Current University of Florida (UF/IFAS) recommended scheduling. Use of the citrus app consistently resulted in lower water use. Note, citrus trees in Florida have become affected by Citrus Greening disease since 2005 and all trees at the three locations in this study was determined to be infected by the pathogen. Water applications were significantly lower using the citrus app (3 out of 3 locations) and UF/IFAS recommendations (1 out of 3 locations) compared with grower schedules. Thus the citrus app used an average of 24% less water than the other two irrigation schedules. Citrus tree sap flow measurements were significantly greater and stem water potential lower for trees irrigated based on schedules produced by the citrus app and current UF/IFAS recommendations compared with trees irrigated using grower&rsquo;s experience. As a result of lower water stress, yields were significantly greater for the citrus app (3 out of 3 locations) than the UF/IFAS recommendations and grower applications. Average increase in yield during the three years of the study was 18%. Yields in Florida citrus orchards have declined by 33% to 50% or more during the past 10 years making the results of this study more noteworthy.</p><br /> <p>&nbsp;</p><br /> <p><strong><span style="text-decoration: underline;">Activities</span></strong><span style="text-decoration: underline;">:</span> Organized and specific functions or duties carried out by individuals or teams using scientific methods to reveal new knowledge and develop new understanding.</p><br /> <p>&nbsp;</p><br /> <p><strong><span style="text-decoration: underline;">Presentations</span></strong></p><br /> <ol><br /> <li>Ferrarezi, R. S.; Geiger, T. C. 2017. Greenhouse cucumber production using sensor-based irrigation. 2017 Irrigation Show &amp; Education Conference. Orlando/FL, United States.</li><br /> <li>Ferrarezi, R. S.; Geiger, T. C.; Weiss, S.; Greenidge J.; Dennery, S. 2017. Microirrigation equipment for okra cultivation in the U.S. Virgin Islands. 2017 Irrigation Show &amp; Education Conference. Orlando/FL, United States.</li><br /> <li>Kadyampakeni, D. 2017. Update on Irrigation and Nutrient Management Studies of HLB Affected Trees.</li><br /> </ol><br /> <p>Presented at the Citrus Institute on April 4, 2017 at South Florida State College, Avon Park, FL.</p><br /> <ol start="4"><br /> <li>Kadyampakeni, D. 2017. Water Use and Irrigation Scheduling Effects on HLB Affected Citrus Trees Grown on &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Sandy Soils. Irrigation Show &amp; Education Conference on November 5-6, 2017; Orlando/FL, United &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; States.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong><span style="text-decoration: underline;">Extension Bulletins</span></strong></p><br /> <p>Zekri, M., A. Schumann, T. Vashisth, D. Kadyampakeni, K. Morgan, B. Boman, and T. Obreza. Fertigation for Citrus Trees. UF/IFAS Extension Publication HS1306, Gainesville, FL. <a href="http://edis.ifas.ufl.edu/hs1306">http://edis.ifas.ufl.edu/hs1306</a></p><br /> <p>Kadyampakeni D.M., K.T. Morgan, M. Zekri, R.S. Ferrarezi, A.W. Schumann and T.A. Obreza. 2017. Irrigation Management of Citrus Trees. In: M.E. Rogers, M.M. Dewdney and T. Vashisth (Eds) 2017-2018 Florida Citrus Production Guide. p. 49-52. Available at: <a href="http://www.crec.ifas.ufl.edu/extension/pest/PDF/2017/Irrigation_Management.pdf">http://www.crec.ifas.ufl.edu/extension/pest/PDF/2017/Irrigation_Management.pdf</a></p><br /> <p>Kadyampakeni, D., K. Morgan, M. Zekri, R. Ferrarezi, A. Schumann, and T. Obreza. 2017. Citrus</p><br /> <p>Irrigation Management. UF/IFAS Extension Publication SL446, Gainesville, FL.</p><br /> <p><a href="http://edis.ifas.ufl.edu/pdffiles/SS/SS66000.pdf">http://edis.ifas.ufl.edu/pdffiles/SS/SS66000.pdf</a></p><br /> <p>Kadyampakeni, D., K. Morgan, M. Zekri, R. Ferrarezi, A. Schumann, and T. Obreza. 2017. Irrigation</p><br /> <p>Management of HLB-Affected Trees. UF/IFAS Extension Publication SL445, Gainesville, FL.</p><br /> <p><a href="http://edis.ifas.ufl.edu/ss659">http://edis.ifas.ufl.edu/ss659</a></p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Nebraska</strong></p><br /> <p>In 2016, Dr. Irmak installed another SDI system in eastern Nebraska (5 acres) that has 136 plots/valves that are controlled individually. The system manifold is has three mainlines with triple-stack orientation. The research project that was conducted by Dr. Irmak on SDI frequency has been published in Irrigation Science. The objectives of this research were to: (i) to evaluate the effects of subsurface drip irrigation (SDI) amount and frequency on maize production and water use efficiency, (ii) develop production functions and quantify water use efficiency, and (iii) develop and analyze&nbsp; crop yield response factors (Ky) for field maize (<em>Zea mays</em> L.). Five irrigation treatments were imposed: fully-irrigated treatment (FIT), 25% FIT, 50% FIT, 75% FIT, rainfed and an over-irrigation treatment (125% FIT). There was no significant (<em>P </em>&gt; 0.05) difference between irrigation frequencies regarding the maximum grain yield; however, at lower deficit irrigation regime, medium irrigation frequency resulted in lower grain yield. There was a decrease in grain yield with the 125% FIT as compared to the FIT, which had statistically similar yield as 75% FIT. Irrigation rate significantly impacted grain yield in 2005, 2006 and 2007, while irrigation frequency was only significant during the 2005 and 2006 growing seasons (two dry years) and the interacting effect was only significant in the driest year of 2005 (<em>P</em> = 0.006). For the pooled data from 2005 to 2008, irrigation rate was significant (<em>P</em> = 0.001) and irrigation frequency was also significant (<em>P</em> = 0.015), but their interaction was not significant (<em>P</em> = 0.207). Overall, there were no significant differences between irrigation frequencies in terms of grain yield. Ky had interannual variation and average seasonal Ky values were 1.65, 0.91, 0.91 and 0.83 in 2005, 2006, 2007 and 2008, respectively, and the pooled data (2005-2008) Ky value was 1.14.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>California</strong></p><br /> <p><strong><span style="text-decoration: underline;">UC Davis</span></strong></p><br /> <p><strong><span style="text-decoration: underline;">Accomplishments</span></strong></p><br /> <p>The evapotranspiration (ET) of a 2-year-old almond tree was measured lysimetrically, and compared to the ET predicted from a recently published young peach tree model.&nbsp; As found in the first year, measured ET values were substantially higher (about double) than predicted by the model, and in this second year, there was a marked overestimate of the soil components by the model.&nbsp; A multi-year almond water production function experiment was continued, and thus far the yield effects of reduced irrigation have been minimal (reductions of from 5 - 25%, depending on location), despite imposing a relatively wide range of irrigation amounts (from 40-60").&nbsp; A multi-year study was continued to document the long-term effects on tree and root health of winter flood irrigations in almond orchards for the purpose of groundwater recharge.&nbsp; Thus far, no negative effects have been observed by applying an additional 24" of water during the dormant season (December/January).&nbsp; The third year of an ongoing walnut irrigation test was performed and demonstrated that plant-based measurements (stem water potential, SWP) could be used to delay the first irrigation in the spring by about 1 month, with no detrimental effects on yield, and evidence was obtained that this practice may improve root health over the long term (years).</p><br /> <p>Extension presentations to growers and other industry personnel have been made at the annual almond and walnut conferences, in addition to presentations at grower meetings that have been organized by extension farm advisors.&nbsp; The following industry supported projects will be continued: 1) Almond Water Production Function, 2) Almond Winter Water Management, 3) Almond Lysimeter (ET), 4) Walnut Early Season Water Management.</p><br /> <p><strong><span style="text-decoration: underline;">Presentations</span></strong></p><br /> <p>Fulton A, Lampinen B, Shackel K. 2017. Walnuts: when to begin the irrigation season. West Cost Nut, March, 4-13.</p><br /> <p><strong><span style="text-decoration: underline;">UC Riverside</span></strong></p><br /> <p><strong><span style="text-decoration: underline;">Outputs</span></strong></p><br /> <p>Research findings were disseminated via refereed journal publications, conference proceedings, and a number of presentations at national and international meetings (see the publication section below). HYDRUS models have been updated with several new capabilities and options that have been developed for various research projects, which in turn have been published in peer-reviewed journals.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong><span style="text-decoration: underline;">Activities</span></strong><strong>: </strong>In 2017, we offered three-day short courses on how to use HYDRUS models at a) CSIRO Land &amp; Water, Adelaide, South Australia, Australia, b) Czech University of Life Sciences, Prague, Czech Republic, c) Colorado School of Mines, Golden, CO, d) the Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, Peoples Republic of China, and e) the Sede Boker Campus of the Ben Gurion University, Israel. Additionally, we also offered one-day short courses at a) the International Workshop of Soil Physics and the Nexus of Food, Energy and Water, Shenyang, China and b) North Carolina State University, Raleigh, NC. About 170 students participated in these short courses.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p>&nbsp;</p><br /> <p><strong><span style="text-decoration: underline;">Short-term Outcomes and Milestones </span></strong></p><br /> <p><strong><em>Objective 1: </em></strong><em>Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches. </em></p><br /> <p><strong><em>Objective 2: </em></strong><em>Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities. </em></p><br /> <p>We continue to expand the capabilities of the HYDRUS modeling environment by developing specialized modules for more complex applications that cannot be solved using its standard versions. The standard versions of HYDRUS, as well as its specialized modules, have been used by myself, my students, and my collaborators in multiple applications described below.</p><br /> <ol><br /> <li><strong><em>The Use of Hydrus Models to Evaluate Various Irrigation and Fertigation Problems </em>- <em>Agricultural Applications </em></strong></li><br /> <li>Phogat et al (2017) used HYDRUS-2D to evaluate crop coefficients, water productivity, and water balance components for wine grapes irrigated at different deficit levels by a sub-surface drip. The impact of deficit irrigation on berry juice composition (Brix, pH and titratableacidity) was lower than the inter-seasonal variability</li><br /> <li>Li et al. (2017a) used experimental field data to assess the spatial distribution of soil water, soil temperature, and plant roots in a drip-irrigated intercropping field with plastic mulch.</li><br /> <li>Aggarwal et al. (2017) used HYDRUS-2D to simulate soil water balance and root water uptake in cotton grown under different soil conservation practices in the Indo-Gangetic Plain. The treatments included conventional tillage (CT), zero tillage (ZT), permanent narrow beds (PNB), permanent broad beds (PBB), ZT with residue (ZT + R), PNB with residue (PNB + R) and PBB with residue (PBB + R). The authors concluded that the Hydrus-2D model may be adopted for managing efficient water use, as it can simulate the temporal changes in SWC and actual transpiration rates of a crop/cropping system.</li><br /> <li>Li et al. (2017b) used HYDRUS-1D to simulate soil water regime and water balance in a transplanted rice field experiment with reduced irrigation.</li><br /> <li>Mallants et al. (2017a) used the UnsatChem module of HYDRUS-1D to asses water quality requirements of coal seam gas produced water for sustainable irrigation. Calculations showed that the use of untreated produced water resulted in a decrease in soil hydraulic conductivity due to clay swelling causing water stagnation, additional plant-water stress, and a reduction in plant transpiration. Results further illustrated that accounting for coupled geochemical, hydrological and plant water uptake processes resulted in more accurate water balance calculations compared to an approach where such interactions were not implemented. Coupling unsaturated flow modeling with major ion chemistry solute transport using HYDRUS provides quantitative evidence to determine suitable water quality requirements for sustainable irrigation using coal seam gas produced water.</li><br /> <li>Mallmann et al. (2017) used HYDRUS-1D to simulate zinc and copper movement in an Oxisol contaminated by long-term pig slurry (PS) amendments. Consideration of root growth and root water uptake processes in HYDRUS-1D simulations improved the description of measured field Zn concentrations. The feasibility of using PS amendments on agricultural Oxisols will be limited by Cu because the soil Cu threshold concentration is exceeded in approximately 30 yr. Moreover, the total loads of both trace metals allowed on agricultural soils are reached very fast when large rates are used, especially for Cu (19 yr), indicating that the long-term disposal of PS on agricultural soils should be done at low doses.</li><br /> <li>Karandish and &Scaron;imůnek (2017) used HYDRUS-2D to simulate nitrogen and water dynamics under various N-managed water saving irrigation strategies. Various scenarios were defined by combining 11 irrigation levels (0&ndash;100%), 8 N fertilization rates (0&ndash;400 kg ha&minus;1) and two water-saving irrigation strategies: deficit irrigation (DI) and partial root-zone drying (PRD). The authors concluded that the HYDRUS-2D model, instead of labor- and time-consuming and expensive field investigations, could be reliably used for determining the optimal scenarios under both the DI and PRD strategies.</li><br /> <li>Hartmann et al. (in press) developed a root growth model and implemented it into HYDRUS. The model considers root growth to be a function of different environmental stresses. The effects of temperature in the root growth module was the first part of the newly developed HYDRUS add-on to be validated by comparing modeling results with measured rooting depths in an aeroponic experimental system with bell pepper.</li><br /> <li>Karandish et al. (in press) applied HYDRUS (2D/3D) for predicting the influence of subsurface drainage on soil water dynamics in a rainfed-canola cropping system. The simulation results demonstrated that the groundwater table management can be an effective strategy to sustain shallow aquifers in the subsurface-drained paddy fields during winter cropping.</li><br /> <li>Karimov et al. (in press) used HYDRUS-1D to evaluate whether a change in cropping pattern can produce water savings and social gains. The analysis was carried out for the Fergana Valley, Central Asia. Modeling results indicate that replacing alfalfa with winter wheat in the Fergana Valley released significant water resources, mainly by reducing productive crop transpiration when abandoning alfalfa in favor of alternative cropping systems. However, the winter wheat/fallow cropping system caused high evaporation losses from fallow land after harvesting of winter wheat. Double cropping (i.e., the cultivation of green gram as a short duration summer crop after winter wheat harvesting) reduced evaporation losses, enhanced crop output and hence food security, while generating water savings that make more water available for other productive uses.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong><em>Hydrological Applications </em></strong></li><br /> <li>Lamorski et al. (2017) used the machine learning method to estimate the main wetting branch of soil water retention curve based on its main drying branch.</li><br /> <li>Slimene et al. (2017) used HYDRUS-2D to evaluate the role of heterogeneous lithology in a glaciofluvial deposit on unsaturated preferential flow.</li><br /> <li>Brunetti et al. (2017) used a surrogate model, i.e., the kriging technique, to approximate the deterministic response of HYDRUS-2D, and to simulate the variably-saturated hydraulic behavior of a contained stormwater filter. Surrogate modeling focuses on developing and using a computationally inexpensive surrogate of the original model. The main aim is to approximate the response of an original simulation model, which is typically computationally intensive.</li><br /> <li>Mallants et al. (2017a) used various modules (e.g., UnsatChem, HP1) of the HYDRUS-1D to demonstrate possible applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. A third application uses the HP1 module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in a soil leached with coal seam gas produced water following some accidental water release scenario. The examples were selected to show how users can tailor the required model complexity to specific needs, such as for rapid screening or risk assessments of various chemicals under generic soil conditions, or for more detailed site-specific analyses of actual subsurface pollution problems.</li><br /> <li>Liang et al. (2017) adapted the HYDRUS-1D model to simulate overland flow and reactive transport during sheet flow deviations. A hierarchical series of models available in HYDRUS-1D to account for both uniform and physical nonequilibrium flow and transport in the subsurface, e.g., dual-porosity and dual-permeability models, up to a dual-permeability model with immobile water, were adapted to simulate physical nonequilibrium overland flow and transport at the soil surface. The developed model improves our ability to describe nonequilibrium overland flow and transport processes and our understanding of factors that cause this behavior.</li><br /> <li>Phogat et al. (2017) used HYDRUS-2D to quantify the long-term stream-aquifer exchange in a variably saturated heterogeneous environment. The model was first calibrated and validated using piezometric heads measured near the stream and then used a) to quantify the long-term dynamics of exchange at stream-aquifer interface and the water balance in the domain and b) to evaluate the impact of anisotropy of geological materials, thickness, and the saturated hydraulic conductivity of the low permeability layer at the streambed, and water table fluctuations on the extent of exchange.</li><br /> <li>Li et al. (2017) used HYDRUS-2D to simulate the effects of lake wind waves on water and solute exchange across the lakeshore. The sensitivity analysis revealed that the hydraulic conductivity of the lakeshore zone and the characteristics of the waves were important factors influencing water and chloride exchange between the lake and groundwater systems. The simulated results helped us to better understand water and solute interactions in the lake&ndash;groundwater system during windy periods.</li><br /> <li>Diamantopoulos et al. (in press) used various FOCUS scenarios, which are used in Europe to assess the potential risk of groundwater to pesticides, in a model comparison study, in which they compared HYDRUS (2D/3D) with PEARL and PELMO. The authors concluded that HYDRUS (2D/3D) can be used as an alternative model for pesticide assessment studies since it provides a conceptual framework consistent with PEARL and PELMO but capable of two- and three-dimensional applications as well.</li><br /> <li>Brunetti et al. (in press) developed a computationally efficient pseudo-3D model for the numerical analysis of borehole heat exchangers. The numerical approach combines a one-dimensional description of the heat transport in the buried tubes of the exchanger with a two-dimensional description of the heat transfer and water flow in the surrounding subsurface soil, thus reducing the dimensionality of the problem and the computational cost. The proposed model was first validated against experimental data collected at two different experimental sites in Japan (with satisfactory results) and then combined with the Morris method used to carry out a sensitivity analysis of thermal properties. Finally, the model was used to investigate the influence of groundwater and lithologic heterogeneities on the thermal behavior of the GSHP.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>III. <strong><em>Fate and Transport of Various Substances (Carbon Nanotubes, Viruses, Explosives) </em></strong></p><br /> <p>&nbsp;</p><br /> <p>With another member of the W3188 group, Scott Bradford we worked on three aspects of the transport of pathogens in the subsurface.</p><br /> <ol><br /> <li>Zhang et al. (2017a) studied the role of cation valance and exchange on the retention and colloid-facilitated transport of functionalized multi-walled carbon nanotubes in a natural soil. The findings indicated that some (more than 20%) of the released MWCNTs by IS reduction and cation exchange were associated with the released clay fraction and suggested the potential for facilitated transport of MWCNTs by water-dispersible colloids.</li><br /> <li>Zhang et al. (2017b) used the C-Ride module of HYDRUS-1D to evaluate the experimental data that indicated that the presence of mobile MWCNTs facilitated remobilization of previously deposited CLD and its co-transport into deeper soil layers, while retained MWCNTs enhanced SDZ deposition in the topsoil layers due to the increased adsorption capacity of the soil. The modeling results demonstrated that the mobility of engineered nanoparticles (ENPs) in the environment and the high affinity and entrapment of contaminants to ENPs were the main reasons for ENP-facilitated contaminant transport.</li><br /> <li>Mark et al (2017) used HYDRUS-1D to evaluate results of the column studies involving the transport of the new, insensitive, energetic compound, NTO (3-nitro-1,2,4-triazol-5-one). The miscible displacement experiments were conducted under steady state and interrupted flow conditions using eight soils having varying physical and geochemical properties. Monod-type kinetics was implemented in HYDRUS-1D to simulate the observed increase in transformation rate with time. Results indicate very low adsorption of NTO in a range of soils, but natural attenuation through transformation that, depending on soil OC content and hydraulic residence time, could result in complete removal of NTO.</li><br /> <li>Arthur et al. (2017) used HYDRUS-1D to evaluate the miscible-displacement column experiments. The results confirmed the impact of sorption on retardation of DNAN (explosive) during transport. It was also shown that under flow conditions DNAN transforms readily with formation of amino transformation products, 2-ANAN and 4-ANAN. The magnitudes of retardation and transformation observed in this study result in significant attenuation potential for DNAN, which would be anticipated to contribute to a reduced risk for contamination of ground water from soil residues.</li><br /> <li>Sasidharan et al. (in press) evaluated transport and fate of viruses under managed aquifer recharge (MAR) conditions in a carbonate aquifer. While existing MAR guidelines only consider the removal of viruses via liquid phase inactivation, our results indicated that virus attachment to the solid phase was several orders of magnitude greater than liquid phase inactivation. Therefore, the authors concluded that current microbial risk assessment methods in the MAR guideline may be overly conservative in some instances.</li><br /> <li><strong><em>Reviews </em></strong></li><br /> <li>Jacques et al. (in press) reviewed recent adaptations of the HPx module of HYDRUS that have significantly increased the flexibility of the software for different environmental and engineering applications. They provide an overview of the most significant changes of HPx, such as coupling transport properties to geochemical state variables, gas diffusion, transport in two and three dimensions, and the support for OpenMP that allows for parallel computing using shared memory. The authors concluded that HPx offers a unique framework to couple spatial-temporal variations in water contents, temperatures, and water fluxes, with dissolved organic matter and CO2 transport, as well as bioturbation processes.</li><br /> <li>&Scaron;imůnek et al. (in press) reviewed new features of the version 3 of the HYDRUS (2D/3D) computer software package. These new features include a flexible reservoir boundary condition, expanded root growth features, and many new graphical capabilities of the GUI. Mathematical descriptions of the new features are provided, as well as two examples illustrating applications of the reservoir boundary condition.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>Texas</strong></p><br /> <p><strong><em>Objective 1.</em></strong> <em>Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></p><br /> <p>Soil moisture sensor testing is being conducted in research field plots at Texas A&amp;M AgriLife Research locations at Bushland, and Halfway, Texas.&nbsp; Soil moisture monitoring also was conducted at three commercial farm locations near Muleshoe, Bushland and Dalhart, Texas.&nbsp; On-site weather stations at all these locations (research and commercial farms) for integration of ET-based irrigation scheduling tools, soil moisture monitoring, and of course on-site precipitation and other weather parameters needed to conduct and interpret the studies.</p><br /> <p>At the Halfway site, soil water sensors include AquaSpy capacitance probes (soil moisture is monitored from 1 ft. to 5 ft. depths, in 4-inch intervals); and Acclima 315L TDR sensors at 0.5 ft., 1 ft., 2 ft., and 3 ft. depths; neutron probe soil moisture measurement is being used for comparison and continuity with ongoing research trials. These sensors are located in research plots under different treatments (conventional <em>vs.</em> no-till; and traditional full-season irrigation strategy <em>vs.</em> delayed seasonal irrigation strategy). All treatments are in cotton planted into terminated wheat (cover crop).&nbsp;</p><br /> <p>Sensors at the Bushland site include Campbell Scientific Inc. CSI650 TDT and Acclima 315L TDR sensors. Placement of these sensors commenced as soon as the irrigation system was functional, and the first crop (winter wheat) was established. Additional sensors are being added to expand monitoring to the additional plots, accommodate more irrigation / cropping system treatments, and to conduct intensive comparisons of different sensors and installation configurations.</p><br /> <p>Decagon GS1 sensors were installed and connected through AgSense datalogger/ telemetry systems at three commercial farms near Muleshoe, Canyon/Bushland and Dalhart, Texas. Depending upon soil depths (horizons, layers, soil depth above caliche layer) at each site, 3 or 4 sensors were placed within the top 3-4 ft. of soil (placements were either 9&rdquo;, 18&rdquo; and 30&rdquo; depths or 6&rdquo;, 12&rdquo;, 24&rdquo; and 36&rdquo; depths, depending on soil depth).&nbsp; Multiple sites at each of these locations represent different crop rotations, soils, and cover crop treatments. Additional sites will be added in the coming crop season.&nbsp; Soil moisture and weather data (from on-site weather stations) are available via a password protected Internet website to the cooperators, research team and interested USDA-NRCS staff, with permission from the cooperators.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 2.</em></strong> <em>Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</em></p><br /> <p>In an effort to evaluate effects on cotton germination, a SDI system was installed on a 1-ha area with the field experiment beginning in 2013 and continuing for the fifth year in 2017. The factors considered are SDI lateral/row position and planting date. Included are five lateral/row position treatments:&nbsp; T1 - 2-m spaced laterals irrigating 1-m crop rows equidistant from the lateral (traditional),&nbsp; T2 - 2-m spaced laterals with two 0.75-m spaced rows equidistant from laterals and 1.25-m distances between row pairs (30-50 inch treatment),&nbsp; T3 - 2-m spaced laterals with 2-m crop rows directly over lateral,&nbsp; T4 - 2-m spaced laterals with one crop row directly over the lateral, and one crop row between laterals, and T5 - 1-m spaced laterals with 1-m rows directly over each lateral. The first planting date of each year is near 10 May with planting to occur in all lateral/row position treatments regardless of soil water condition. The second date is in the period from 14 to 35 days following the first planting with the planting date determined by the occurrence of favorable soil water conditions in the T1 treatment. Irrigation of all treatments is at approximately 70% ET, limited by an irrigation capacity of 5 mm d^-1.&nbsp; Pre-plant irrigations of up to 125 mm are initiated 25 days prior to each approximate planting date and will continue for up to 10 days following planting or until seed germination has occurred in all treatments within a planting date.&nbsp; 2013 and 2016 results showed highest yield in early planted treatments of T1, T2, and T5.&nbsp; 2014 results showed relative small differences in yield due to planting date or row/lateral arrangement due to higher than average season rain. 2015 harvest results were non-conclusive due to a severe hail event on August 28.&nbsp; Analysis of 2017 data is currently underway. This experiment will ultimately provide economic comparisons of water value (crop yield) relative to initial irrigation system cost and management.</p><br /> <p>A SDI experiment was initiated in 2014 and continued through 2017 that focused on efficiencies of pre- and early-season irrigations of cotton with deficit irrigation capacities. Treatments include pre-plant irrigations of 2 and 4 inches and early growing season irrigation capacities of 0.0, 0.1, and 0.2 in/day resulting in six treatments plus "pre-plant only" check.&nbsp; Irrigation intervals are every seven days during cotton reproductive and maturation periods.&nbsp; Tests were inconclusive due to late replanting in 2014 and heavy rains and hail during the pre-plant and early season irrigation periods in 2015. Cotton was replanted to grain sorghum due to hail and wind in 2016.&nbsp; Analysis of 2017 data is currently underway. The results to date indicate no significant differences in yield due to irrigation treatments, therefore, water value was highest in treatments with no or limited pre-plant and early season irrigations. By applying recent field research findings and observing the frequency of challenging early season weather conditions, we hypothesize that irrigation productivity can be increased by up to 10% over typical limited irrigation capacity SDI strategies.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 3.</em></strong> <em>Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</em></p><br /> <p>The DIEM Dashboard for Irrigation Efficiency Management irrigation scheduling and management tool is being evaluated in research and commercial farm operations.&nbsp; DIEM integrates soil moisture (water balance), crop ET, and irrigation system efficiency and constraints to optimize irrigation management for cotton production systems. DIEM is unique in that it provides a prescription (pre-season, and updated throughout the season) to optimize limited irrigation. &nbsp;DIEM is a web-based tool; beta test accounts can be requested free of charge from diem.tamu.edu.</p><br /> <p>&nbsp;</p><br /> <p>Microirrigation research updates and management recommendations are presented in a variety of &ldquo;face-to-face&rdquo; venues, including traditional Extension &ldquo;CEU&rdquo; meetings for agricultural producers, irrigation professionals, agency staff, agribusiness and other interested audiences.&nbsp; Examples of irrigation workshops and presentations are listed in the Educational Activities section below. Professional development events (in person and webinars) were conducted for County Extension faculty, with emphasis on the Texas High Plains, Rolling Plains and West Texas where there is most producer interest in microirrigation (especially subsurface drip irrigation).&nbsp; Jim Bordovsky and Dana Porter presented several invited presentations for Groundwater Conservation Districts, irrigation conferences, university classes, and other groups/venues.&nbsp; These and other technology transfer activities are included below.&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong><span style="text-decoration: underline;">Educational Activities</span></strong></p><br /> <p><strong><span style="text-decoration: underline;">Seminars, workshops similar education events</span></strong></p><br /> <p>Porter, Dana. 2017. High Plains Irrigation Conference and Trade Show, Amarillo, TX, February 4, 2017. CEUs provided for Irrigation Association (IA) Certified Irrigation Designers (CID), Certified Agricultural Irrigation Specialists (CAIS) and American Society of Agronomy Certified Crop Advisers (CCA).</p><br /> <p>Porter, Dana. 2017. Monthly webinar and in-person soil and water management training series for Texas A&amp;M AgriLife Extension Agents. December 2016 - August 2017.</p><br /> <p><strong><span style="text-decoration: underline;">Papers and presentations</span></strong></p><br /> <p><strong><span style="text-decoration: underline;">Invited papers, presentations, and lectures </span></strong></p><br /> <ol><br /> <li>Bordovsky, J.P. 2017. Deficit irrigation research. High Plains Underground Water Conservation District Board of Directors meeting. Lubbock, TX. October 10, 2017.</li><br /> <li>Porter, D. 2016. Dashboard for Irrigation Efficiency Management: program overview and planned field testing and evaluation. High Plains Underground Water Conservation District Board of Directors meeting. Lubbock, TX. December 13, 2016.</li><br /> <li>Porter, D. 2017. Agricultural Irrigation. Invited Panelist on &ldquo;Planning Ahead: Groundwater Projects for Tomorrow&rsquo;s Needs&rdquo;; 2017 Texas Groundwater Summit, Texas Alliance of Groundwater Districts, San Marcos, TX. August 29-31, 2017.</li><br /> <li>Porter, D. 2017. Irrigation Management and Crop Water Management. Guest Lecture in course, Crop Stress Management.&nbsp; Texas A&amp;M University Department of Soil and Crop Sciences. October 3, 2017.</li><br /> <li>Porter, D. 2017. Irrigation Water Quality and Salinity Management. Guest Lecture in course, Crop Stress &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (recorded presentation). Texas A&amp;M University Department of Soil and Crop Sciences. &nbsp; October 5, 2017.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong><span style="text-decoration: underline;">Conference or symposium proceedings: papers and posters presented</span></strong></p><br /> <ol><br /> <li>Andales, A., J. Bordovsky, and J. Agular. 2016. Irrigation scheduling tools in the Ogallala Region. USDA-ARS Ogallala Water CAP Report /Workshop. Denver, CO. Dec. 8, 2016.</li><br /> <li>Bordovsky, J.P. 2017. Texas High Plains cotton irrigation research. Oklahoma Irrigation Conference. Altus, OK. March 1, 2017.</li><br /> <li>Bordovsky, J.P. 2017. Dashboard for irrigation efficiency management (DIEM). 2017 Irrigation Association Technical Conference. Orlando, FL. Nov. 6-10, 2017.</li><br /> <li>Jordan, S., Bordovsky, J.P. and Porter, D.O. 2017. Comparison of multi-sensor capacitance and TDR soil moisture measurement methods in Texas South Plains irrigated cotton. Poster presentation. 2017 Beltwide Cotton Conferences. Dallas, TX. January 3-4, 2017.</li><br /> <li>Porter, D., J. Bordovsky, T.Marek, C. Hillyer. 2016. Soil sensor measurement research and extension activities in the Texas High Plains. USDA-ARS CIG Reporting/Workshop. Goodwell, OK. November 22, 2016.</li><br /> <li>Porter, Dana. 2016. Integrated projects and activities technology transfer / outreach of the Ogallala Water Coordinated Agriculture Project. (USDA-NIFA-CAP). Denver, CO. December 8-9, 2016.</li><br /> <li>Porter, Dana, Kevin Wagner, Jonathan Aguilar, Dan Rogers, Thomas Marek, Gary Marek, Saleh Taghvaeian, Freddie Lamm, Amy Kremen, Meagan Schipanski, and David Brauer. Education and Technology Transfer in Agricultural Water Management: Effective Communication with Stakeholders. Annual Conference, Universities Council of Water Resources.&nbsp; Ft. Collins, CO. June 13-15, 2017.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong><span style="text-decoration: underline;">Presentations at Extension meetings&nbsp; </span></strong></p><br /> <ol><br /> <li>Bordovsky, J.P. 2017. Optimizing limited water. 2017 Lubbock / Hale County Precision Irrigation Workshop. Abernathy, TX. March 23, 2017.</li><br /> <li>Porter, Dana. 2017. South Plains irrigation update. Southern Mesa Ag Conference. Lamesa, TX. January 16, 2017.</li><br /> <li>Porter, Dana. 2017. New and Improved Irrigation Technology. Llano Estacado Cotton Conference. Muleshoe, TX. January 30, 2017.</li><br /> <li>Porter, Dana. 2017. South Plains irrigation update. South Plains Ag Conference. Brownfield, TX. January 17, 2017.</li><br /> <li>Porter, Dana. 2017. Precision irrigation tools. Hub of the Plains Ag Conference, Lubbock, TX. February 2, 2017.</li><br /> <li>Porter, Dana. 2017. Irrigation scheduling, monitoring and new developments. Lubbock / Hale County Precision Irrigation Workshop. Abernathy, TX. March 23, 2017. (20 attendees)</li><br /> <li>Porter, Dana. 2017. Dashboard for Irrigation Efficiency Management (DIEM) training for county agent beta testers. Lubbock, TX. February 23, 2017.</li><br /> <li>Porter, Dana. 2017. Understanding crop water use and management, soil moisture characteristics; soil-plant-atmosphere relationships; and planning for 2017 on-farm demonstrations. Texas A&amp;M AgriLife Extension County Agent Professional Development Series. Lubbock, TX. March 23, 2017.</li><br /> <li>Porter, Dana. 2017. Wastewater Irrigation Management for Dairies. Dairy Outreach Program Area meeting, Dublin TX. April 6, 2017.</li><br /> <li>Porter, Dana. 2017. Irrigation and Precision Agriculture Technologies. Path to the Plate County Agent training and field demonstrations. College Station, TX. June 1, 2017.</li><br /> <li>Porter, Dana. 2017. Irrigation Management for Cotton Production. Cotton subject matter professional development training for county agents.&nbsp; Texas A&amp;M AgriLife Extension Service. Lubbock, TX. July 26, 2017.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong><span style="text-decoration: underline;">Field days / crop tours</span></strong></p><br /> <ol><br /> <li>Bordovsky, J.P. 2017. Nuffield Visiting Scholars of New South Wales, Australia toured irrigation research facilities and ongoing projects at Texas A&amp;M AgriLife Research. Halfway, TX. June 23, 2017.</li><br /> <li>Bordovsky, J.P. and Dana Porter. 2017. Irrigation practices and research activities in the Southern High Plains. Site tour and on-farm instruction. Texas 4-H Water Ambassadors. Halfway, TX. July 14, 2017. (Presentations were livestreamed on the Texas 4-H Water Ambassadors Facebook page.)</li><br /> <li>3Bordovsky, J.P. 2017. Deficit irrigation research and strategies. Oral presentation. West Central Research and Extension Center Water and Crops Field Day. North Platte, NE. August 24, 2017.</li><br /> <li>Bordovsky, J.P. 2017. Deficit irrigation research. Oral presentation. 12th Annual Texas Alliance for Water Conservation Field Day. Edmonson, TX. September 6, 2017.</li><br /> <li>Porter, Dana. 2016. Irrigation and Water Management for High Plains Dairies. Southwest Dairy Day. Dalhart, TX. October 20, 2016.</li><br /> <li>Porter, Dana. 2017. Irrigation System Capabilities and Management. Texas A&amp;M AgriLife Research Corn Breeders Tour. Lubbock and Halfway, TX. August 16-17, 2017.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Oregon</strong></p><br /> <p>Broad expansion of microirrigation is needed. Unless timely action is taken, it is anticipated that water supply and water quality related crises will affect economies and resources of national and international importance. Microirrigation can reduce the waste of water to a negligible amount and reduce the transport of contaminants to surface water and groundwater. Irrigation events</p><br /> <p>can be fine-tuned to spoon feed water and nutrients just in time to minimize plant water stress. Microirrigation can optimize crop production (more crop per drop) and in many cases, increase the quality of agricultural products. Successful experimental microirrigation results will be scaled up to commercial size through this project. Microirrigation information will be transferred effectively to growers through many venues.</p><br /> <p>&nbsp;</p><br /> <p><strong><em><span style="text-decoration: underline;">What was accomplished under the project goals?</span></em></strong></p><br /> <p><strong><em>Objective 1:</em></strong> Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</p><br /> <p>Vineyards -&nbsp; In OR, WA, and CA soil-based measurements of soil water tension (SWT) managed drip irrigation scheduling is being combined with weather-based crop evapotranspiration managed drip irrigation scheduling for vineyard production.&nbsp; We envision the optimization of yield and quality of vineyard production and financial return in cooperation with SmartVineyards. Ground truth of plant water potential is also being measured. Early during the growing season there are risks of wasting water and nutrients from over irrigation when the flush of early annual vine growth can be favored by minimal or very low levels of water stress. Later in the season, the relative amount of water stress that is most beneficial for the final product increases with the grape development stage. The ideal amount and timing (trajectories) of water stress (as measured by soil, plant, or weather data) are being studied for various cultivars, weather patterns, and sites. In Oregon we seek to measure the trajectories of stress. Modification of the stress trajectory holds the promise of better water use efficiency, protection of water quality, optimization of product quality, and the realization of providing a better return on vineyard investment. The approach is to collect and evaluate automated data that is interpreted and provided in real time to growers.</p><br /> <p><span style="text-decoration: underline;">Automation of data collection and delivery.</span> The automated approach to collect SWT data in vineyards (above) is being tested on onion, potato, quinoa, and stevia.</p><br /> <p><span style="text-decoration: underline;">Seed production of native plants.</span> In Oregon fixed irrigation schedules are being compared to soil- and weather-based scheduling for seed production from native plants. Plant species required 0 to 200 mm of supplemental irrigation per year to maximize seed yield. For a given species, yield responses to irrigation varied substantially by year. We have determined that accounting for rainfall during and prior to seed production improves the accuracy of estimating the amount of irrigation required.&nbsp; Species differ in the preceding time interval where precipitation needs to be counted against the irrigation requirement.</p><br /> <p><span style="text-decoration: underline;">Stevia</span>&nbsp; Although drip irrigation has been used to produce <em>Stevia rebaudiana</em>, few people have determined the best irrigation criteria in terms of soil water tension or crop evapotranspiration. Stevia leaf production was tested using irrigation onset criteria to trigger irrigation at different levels of SWT and triggering irrigation at 10 to 20 kPa optimized leaf yield. Equivalent levels of crop evapotranspiration were calculated and are being compared to reference evapotranspiration and the crop response to SWT.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong><em>Objective 2:</em></strong> Develop microirrigation designs and management practices that can be appropriately scaled to site- specific characteristics and end-user capabilities.</p><br /> <p><span style="text-decoration: underline;">Protection of fresh produce from human pathogens in irrigation water</span> Many fresh fruit and vegetables grown with drip irrigation are commonly consumed raw; therefore, they are subject to the FDA's provisions of the Food Safety Modernization Act. A major portion of the Produce Rule focuses on the microbiological quality of irrigation water used in the production of raw vegetable products. We conducted multi-year studies on the effect of contaminated irrigation water applied via furrow or drip irrigation on the relative fate of generic <em>E. coli</em> in water, in soil, and on onions during growth, curing, harvesting, and storage.</p><br /> <p>It is very important to have in irrigation practices to this food safety modernization act to use water effectively to produce fresh vegetables for fresh consumption. We have studied actual bacterial movement in the soil from water that exited drip tape. The water sources were highly contaminated with <em>E. coli</em>. Experiments have repeatedly shown that the bacteria in the water entering the soil did not move appreciably towards the onion bulbs. Furthermore the <em>E. coli</em> did not survive long in the soil or on the surface the bulbs.</p><br /> <p><span style="text-decoration: underline;">Delivery of herbicides.</span>&nbsp; Herbicides were applied through the drip irrigation system in the hopes of achieving better control of yellow nutsedge. Outlook herbicide applied through drip irrigation was successful in helping to control yellow nutsedge.&nbsp; This work is designed to expand the labeled use of drip-applied Outlook herbicide to control yellow nutsedge.</p><br /> <p><span style="text-decoration: underline;">Delivery of fungicides.</span> Fungicides were applied through the drip system to try to obtain better control of root fungi. Pink root and plate rot were not significant problems in the onion fields used for the trials and the products tested were not beneficial.</p><br /> <p><span style="text-decoration: underline;">Adaptation of drip irrigation for potato production.</span> Potato production is generally conducted with sprinkler irrigation. In the US drip irrigation has not been cost effective in comparison to sprinkler irrigation. We sought to change the drip irrigation configuration so that the drip irrigation system could be more efficiently utilized. Rows of potato plants were moved so that two rows of plants could be irrigated with a single drip tape. In this way only half the length of tape was needed to grow a potato crop. Currently sprinkler irrigation is used in part to cool the environment. To try to cool the environment of the developing potato tubers, we tested production with potatoes planted into flat beds. Double rows of plants with drip tapes 72 inches apart used less drip tape and water in 2017.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong><em>Objective 3:</em></strong> Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</p><br /> <p>In objective 1 above, the automatic collection, evaluation, and deliver of soil and weather data is described. The goal is to interpret and deliver results, predictions, and projections in real time to growers' smart phones and laptops based on growers' demands. Growers are gaining real time access to information from their fields for water management decision making. These emerging tools and technology for growers have the potential to simultaneously optimize economic outcomes and minimize the losses of water and nutrients.</p><br /> <p><strong><span style="text-decoration: underline;">&nbsp;</span></strong></p><br /> <p><strong><span style="text-decoration: underline;">What opportunities for training and professional development has the project provided?</span></strong></p><br /> <p>Undergraduate students were trained in research protocols and learned about crop irrigation and management.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong><span style="text-decoration: underline;">How have the results been disseminated to communities of interest?</span></strong></p><br /> <p>Results were communicated to growers by means of field days, workshops, grower meetings, written, and "on-line" reports. Results were disseminated at 3 different 2016 field days, through numerous written reports and presentations for growers and the public, scientific and international presentations, and by reports published on the internet.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong><em>What do you plan to do during the next reporting period to accomplish the goals?</em></strong></p><br /> <p>Continue to 1) collect and deliver soil water tension data and interpretations to vineyard managers and growers of other crops to optimize drip-irrigation scheduling, 2) determine the irrigation criteria for seed production of perennial native plants where seed is needed for restoration activities and communicate the results to growers and others, 3) examine the possibility improving product effectiveness and reducing costs by injecting herbicides and fungicides through drip irrigation systems, and 4) actively disseminate results through field days, workshops, reports to growers and researchers, and web based reports on the internet.</p><br /> <p><strong><em><span style="text-decoration: underline;">&nbsp;</span></em></strong></p><br /> <p><strong><strong><em><span style="text-decoration: underline;"><br /> </span></em></strong></strong></p><br /> <p><strong><em><span style="text-decoration: underline;">International invited presentations</span></em></strong></p><br /> <ol><br /> <li>Shock, C.C. 2017. Creation and adoption of smart agriculture innovations to cope with climatic uncertainty. Keynote address at the International Conference on Biodiversity, Climate Change Assessment and Impacts on Livelihood, Hotel Crown Plaza &ndash; Soaltee, Kathmandu, Nepal<strong>,</strong> 10-12 January.</li><br /> </ol><br /> <h1>2.&nbsp;&nbsp;&nbsp;&nbsp; Shock, C.C. 2017. Irrigation management for climate-smart agriculture. Keynote address at the International Conference on Technological Advances in Climate-Smart Agriculture and Sustainability (TACSAS 2017). Shri Guru Gobind Singhji Institute of Engineering and Technology, Nanded, India, 16-18 January.</h1><br /> <h1>3.&nbsp;&nbsp;&nbsp;&nbsp; Shock, C.C. 2017. Climate-smart agriculture. Jain Irrigations Systems, Jalgaon, India, 24 January.</h1><br /> <h1>4.&nbsp;&nbsp;&nbsp;&nbsp; Shock, C.C. 2017. Are field experiments easy? How to design, manage, and evaluate field experiments. China Agricultural University. Beijing, China. 6 June.</h1><br /> <h1>5.&nbsp;&nbsp;&nbsp;&nbsp; Shock, C.C., E.B.G. Feibert, and N.L. Shaw. 2017 Ecological restoration hurdles to use rarely cultivated plants; Developing reliable seed production technology. Society for Ecological Restoration, Iguassu Falls, Parana, Brazil, 31 August.</h1><br /> <p><strong><span style="text-decoration: underline;">&nbsp;</span></strong></p><br /> <p><strong><em><span style="text-decoration: underline;">National presentations</span></em></strong></p><br /> <ol><br /> <li>Shock, C.C., E.B.G. Feibert, A. Rivera, L.D. Saunders, N.L. Shaw, and F. Kilkenny. 2017. Irrigation requirements for seed production of <em>Eriogonum</em> species for use in Intermountain West rangeland restoration. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 21 September.</li><br /> <li>Feibert, E.B.G., C.C. Shock, A. Rivera, L.D. Saunders, N.L. Shaw, and F. Kilkenny. 2017. Irrigation requirements for Intermountain West rangeland legume seed production. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 19 September.</li><br /> <li>Shock, C.C. and F.X. Wang. 2017. Controlling irrigation onset by soil water tension. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 22 September.</li><br /> <li>Foley, K., C.C. Shock, and M. Santelmann. 2017. Drivers and barriers to producers&rsquo; voluntary adoption of practices that protect water quality. Annual meeting of the American Society of Horticultural Science, Waikoloa, HI, 21 September.</li><br /> <li>Shock, C.C., E.B.G. Feibert, and N.L. Shaw. 2017. Oregon Report to W3128, Scaling microirrigation technologies to address global water challenges. Annual meeting of the W3128 working group, 5 November, Orlando, Florida.</li><br /> <li>Shock, C.C., F.X. Wang, A.D. Campbell, and H. Dominguez-Aguire. 2017. Triggering drip irrigation onset by soil water tension. International Irrigation Show, Orlando, Florida, 7 November.</li><br /> <li>Foley, K., C.C. Shock, and M. Santelmann. 2017. Drivers and barriers to producers&rsquo; voluntary adoption of practices that protect water quality. International Irrigation Show, Orlando, Florida, 8 November.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong><em><span style="text-decoration: underline;">Regional presentations</span></em></strong></p><br /> <ol><br /> <li>Shock, C.C., S.R. Reitz, E. Feibert, A. Rivera, H. Kreeft, and J. Klauzer. 2017. Overview of research on the Food Safety Modernization Act. Idaho-Eastern Oregon Onion Growers&rsquo; Association Annual Meeting, Ontario, OR. 7 February.</li><br /> <li>Shock, C.C. 2017. Drip irrigation for onion: growers&rsquo; adoption of innovations. Clearwater Supply Annual Drip irrigation Meeting, 8 January, Ontario, Oregon.</li><br /> </ol><br /> <p><strong><span style="text-decoration: underline;">&nbsp;</span></strong></p><br /> <p><strong><em><span style="text-decoration: underline;">Annual Reports</span></em></strong></p><br /> <ol><br /> <li>In Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., and Saunders, L. D. 2017. Onion internal quality in response to artificial heat and heat mitigation during bulb development. p 43-53. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., and Saunders, L. D. 2017. Timing of Internal quality problems in onion bulbs. p 54-62. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Reitz, S. R., Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Kreeft, H., and Klauzer, J. 2017. Safe production of onion &ndash; 2016, understanding the fate of <em>Escherichia coli</em> in the soil. p 82-92. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Reitz, S. R., Noble, J., Shock, C. C., Feibert, E. B. G., Rivera, A., and Saunders, L. D. 2017. Thrips and iris yellow spot virus management in the Treasure Valley. p 99-119. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Kilkenny, F., and Shaw, N. L. 2017. Direct surface seeding systems for the establishment of native plants in 2016. p 123-130. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for seed production of several native wildflower species planted in the fall of 2012. p 131-139. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Native beeplant seed production in response to irrigation in a semi-arid environment. p 140-144. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for native buckwheat seed production in a semi-arid environment. p 145-152. In: Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Johnson, D. A., Bushman, B. S., Shaw, N. L., and Kilkenny, F. 2017. Prairie clover and basalt milkvetch seed production in response to irrigation. p 153-159. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for seed production of five <em>Lomatium</em> species in a semi-arid environment. p 160-173 In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Shock, C. C., Feibert, E. B. G., Rivera, A., Saunders, L. D., Shaw, N. L., and Kilkenny, F. 2017. Irrigation requirements for seed production of five native <em>Penstemon</em> species in a semi-arid environment. p 174-186. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> <li>Buhrig, W., Shock, C. C., Feibert, E. B. G., and Saunders, L. D. 2017. Wireless sensor network for &lsquo;on farm&rsquo; soil moisture data acquisition and irrigation scheduling. p 231-237. In Shock C.C. (Ed.) Oregon State University Agricultural Experiment Station, Malheur Experiment Station Annual Report 2016, Department of Crop and Soil Science Ext/CrS 157.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong><em><span style="text-decoration: underline;">Field days</span></em></strong></p><br /> <ol><br /> <li><em> Native Wildflower Seed Production Field Day</em>, (all trials with subsurface drip irrigation), Malheur Experiment Station, Oregon State University, Ontario, Oregon, 18 May 2017</li><br /> <li>&ldquo;Planting native wildflower seeds&rdquo;, Erik Feibert and Clint Shock</li><br /> <li>&ldquo;Wildflower sequence of flowering&rdquo;, Clint Shock and Erik Feibert</li><br /> <li>&ldquo;Plants supporting pollinators&rdquo;, Clint Shock and Erik Feibert</li><br /> <li>&ldquo;Irrigation needs to produce seed of native wildflowers&rdquo;, Clint Shock and Erik Feibert</li><br /> <li>&ldquo;Seed harvests and expected seed yields&rdquo;, Erik Feibert and Clint Shock</li><br /> <li>&ldquo;Drip irrigation systems&rdquo;, Erik Feibert and Clint Shock</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li><em>Summer Farm Festival and Malheur Experiment Station Field Day</em>, Malheur Experiment Station, Oregon State University, Ontario, Oregon, 12 July 2017.</li><br /> </ol><br /> <p>Onion and potato drip irrigation tour. We show cased a study evaluating the response of multiple onion</p><br /> <p>cultivars to the recently registered method of applying Outlook (dimethenamid-p) through drip irrigation.&nbsp; Evaluation of drip irrigation and comparison to sprinkler irrigation for potato to lower the comparative cost of drip irrigation. Latest work on internal rot in onion. Joel Felix, Clint Shock, and Erik Feibert.</p><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><em>Onion Variety Day,</em> (all trials with drip irrigation), Malheur Experiment Station, Oregon State University, Ontario, Oregon, 22 August 2017.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="4"><br /> <li><em>Treasure Valley Irrigation Conference</em>, Ontario, OR. 14 December 2017.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Oklahoma</strong></p><br /> <p><strong><em>Objective 1.</em></strong> Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</p><br /> <p>Numerous research and extension activities have been conducted at Oklahoma State University during the reporting period to promote effective irrigation scheduling methods. A multi-state (OK, TX, KS) project on promoting sensor-based technologies to improve irrigation scheduling was successfully continued. As part of this project, canopy temperature and soil moisture sensors were installed at the Oklahoma Panhandle Research and Extension Center near Goodwell, OK, where corn and sorghum plots receive variable levels of irrigation application using a subsurface drip irrigation (SDI) system. The goal is to investigate how these two different types of irrigation scheduling approaches interact and how they can be utilized in managing SDI systems. In addition, soil moisture sensors (single sensors and probes) were installed at six other locations in cooperation with local growers. Sensors were evaluated for their accuracy, sensitivity to irrigation applications, and usefulness in improving irrigation scheduling. In choosing these sites a major criteria was to cover a wide range of crops, soil textures, and soil salinities.</p><br /> <p>&nbsp;</p><br /> <p><strong><em><span style="text-decoration: underline;">Objective 3.</span></em></strong> Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</p><br /> <p>Dissemination of information on adoption of microirrigation systems was accomplished by presenting at numerous field days, meetings, workshops, and in-service trainings.</p><br /> <p>&nbsp;</p><br /> <p><strong><span style="text-decoration: underline;">Presentations:</span></strong></p><br /> <ol><br /> <li>Stivers J, Taghvaeian S. 2016. Field Comparison of Soil Moisture Sensors. 9^th International Conference on Irrigation and Drainage. Oct. 11-14, 2016; Fort Collins, CO.</li><br /> <li>Taghvaeian S. 2016. Irrigation Monitoring and Evaluation. Organic Oklahoma Fall Conference. Oct. 7, 2016; Oklahoma City, OK. (Contact hours: 11)</li><br /> <li>Taghvaeian S. 2016. Reuse of Wastewater using Drip Irrigation. OK Onsite Wastewater Conference. Nov. 10, 2016; Stillwater, OK. (Contact hours: 130)</li><br /> <li>Taghvaeian S. 2017. Sensor Technologies to Improve Irrigation Water Management. Central MN Irrigation &amp; Nitrogen Management Clinic. Feb. 2, 2017; Ottertail, MN. (Contact hours: 65)</li><br /> <li>Taghvaeian, S. 2017. Irrigation Management Approaches. Irrigation Association Agriculture Faculty Academy. Jun. 8-Jun. 9, 2017; Grand Island, NE. Contact hours: 73</li><br /> <li>Taghvaeian, S. 2017. Grape Irrigation Management. OK Grape Management Course. Jul. 6, 2017; Perkins, OK. Contact hours: 15</li><br /> <li>Taghvaeian, S. 2017. Pecan Irrigation Management. OK Pecan Management Course. Jul. 11, 2017; Perkins, OK. Contact hours: 34</li><br /> <li>Taghvaeian, S. 2017. Monitoring Soil Water Content. Soil Workshop In-Service Training. Jul. 21, 2017; Perkins, OK. Contact hours: 10</li><br /> <li>Taghvaeian, S. 2017. Soil Moisture Sensor Technology. Fall Crops Tour. Sep. 1, 2017; Goodwell, OK. Contact hours: 50</li><br /> <li>Taghvaeian, S. 2017. Using Soil Moisture Sensors to Improve Cotton Irrigation. 2017 Carnegie Co-op Gin Fall Cotton Tour. Sep. 21, 2017; Hydro, OK. Contact hours: 23</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>Washington</strong></p><br /> <p><strong><span style="text-decoration: underline;">What was accomplished under the project objectives?</span></strong></p><br /> <p><strong><em>Objective 1:</em></strong> Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</p><br /> <p>Three field research locations are being used to col

Publications

<ol><br /> <li>Shock, C.C., E.B.G. Feibert, A. Rivera, L.D. Saunders, N.L. Shaw, and F. Kilkenny. 2017. Irrigation requirements for seed production of two <em>Eriogonum</em> species in a semi-arid environment. HortScience. 52(9):1188&ndash;1194. doi: 10.21273/HORTSCI12186-17</li><br /> <li>Zhang, Y.I., F-X. Wang, C.C. Shock, K-J. Yang, S-Z. Kang, J-T. Qin, S-E. Li. 2017. Effects of plastic mulch on the radiative and thermal conditions and potato growth under drip irrigation in arid Northwest China. Soil and Tillage Research 172:1&ndash;11.</li><br /> <li>Zhang, Y-L., F-X. Wang, C.C. Shock, K-J. Yang, S-Z. Kang, J-T. Qin, and S-E. Li. 2017. Influence of different plastic film mulches and wetted soil percentages on potato grown under drip irrigation. Agricultural Water Management. 180:160&ndash;171.</li><br /> <li>Zhang, Y-L., F-X. Wang, C.C. Shock, K-J. Yang, Z. Huo, N. Song, and D. Ma. 2017. Potato</li><br /> <li>performance as influenced by the proportion of wetted soil volume and nitrogen under drip</li><br /> <li>irrigation with plastic mulch. Agricultural Water Management 179:260&ndash;270.</li><br /> <li>Parris, C.A., C.C. Shock, and M. Qian. 2017. Soil water tension irrigation criteria affects <em>Stevia rebaudiana</em> leaf yield and leaf steviol glycoside composition. HortSci. 52(1):154&ndash;161. doi: 10.21273/HORTSCI11352-16</li><br /> <li>Gonzalez-Fuentes JA, Shackel K, Lieth JH, Albornoz F, Benavides-Mendoza A, Evans YA. 2016. Diurnal root zone temperature variations affect strawberry water relations, growth, and fruit quality. Scientia Hort. 203:169-177.</li><br /> <li>Castellarin SD, Gambetta GA, Wada H, Krasnow MN, Cramer GR, Peterlunger E, Shackel KA, Matthews MA. Characterization of major ripening events during softening in grape: turgor, sugar accumulation, abscisic acid metabolism, colour development, and their relationship with growth. J. Ex. Bot. 67:709-722</li><br /> <li>Spinelli GM, Shackel KA, Gilbert ME. 2017. A model exploring whether the coupled effects of plant water supply and demand affect the interpretation of water potentials and irrigation management. Ag. Water Management 192:271-280.</li><br /> <li>Zuniga, C., L.R. Khot, S. Sankaran, and P.W. Jacoby. 2017. High resolution multispectral and thermal remote sensing based water stress assessment in grapevines to evaluate subsurface irrigation technique effects. Remote Sensing 9(9):961-976; doi:10.3390/rs9090961. [(ISSN 2072-4292) Impact Factor 3.244].</li><br /> <li>Kisekka, I., T. Oker, G. Nguyen, J. Aguilar and Danny Rogers. 2017. Revisiting Precision Mobile Drip Irrigation under Limited Water. Irrigation Science. 1-18. DOI: 10.1007/s00271-017-0555-7.</li><br /> <li>Lamm, F.R. and D. H. Rogers. &nbsp; Longevity and performance of a subsurface drip irrigation system.&nbsp; Trans ASABE 60(3):931-939</li><br /> <li>Lamm, F. R. and J. Puig-Bargu&eacute;s. &nbsp; Simple equations to estimate flushline diameter for subsurface drip irrigation systems. Trans. ASABE 60(1):185-192.</li><br /> <li>Lamm, F. R. &nbsp; Subsurface drip irrigation and possibilities in Alfalfa.&nbsp; In: Proc., 2016 California Alfalfa and Forage Symposium, Reno, NV, Nov 29‐Dec 1, 2016. UC Cooperative Extension, Plant Sciences Department, University of California, Davis, CA 95616.&nbsp; pp. 79-90.</li><br /> <li>Oker E. Tobias and I. Kisekka. 2017. Effect of Mobile Drip Irrigation on corn yield, biomass and water productivity. 2017. Paper #: 1701494. ASABE AIM Jul 16-19, 2017 Spokane, Washington USA.</li><br /> <li>Slack, D.C., R. Reyes Esteves, A. Espejel, B. Oyorsaval and Y. Ma. 2017. Subsurface Drip Irrigation: A Technology for Safer Irrigation of Vegetable Crops. Engineering and Applied Science Research 44(2):111-114</li><br /> <li>Chaibandit, K., S. Konyai and D.C. Slack. 2017. Evaluation of the Water Footprint of Sugarcane in Eastern Thailand. Engineering Journal 21(5): 193-201. DOI:10.4186/ej.2017.21.5.193.</li><br /> <li>Kadyampakeni, D.M. and K.T. Morgan. 2017. Irrigation scheduling and soil moisture dynamics influence water uptake by Huanglongbing affected trees. Scientia Horticulturae 224:272-279. <a href="http://dx.doi.org/10.1016/j.scienta.2017.06.037">http://dx.doi.org/10.1016/j.scienta.2017.06.037</a></li><br /> <li>Hamido, S.A., K.T. Morgan and D.M. Kadyampakeni. 2017. The effect of huanglongbing on young citrus tree water use. HortTechnology 27(5):659-665, doi: 10.21273/HORTTECH03830-17</li><br /> <li>Hamido, S.A., K.T. Morgan, R.C. Ebel amd D.M. Kadyampakeni. 2017. Improved irrigation management of sweet orange with Huanglongbing. HortScience 52(6):916-921. 2017. doi: 10.21273/HORTSCI12013-17</li><br /> <li>Baath G. S., M. K. Shukla, P. W. Bosland, R. L. Steiner, and S. J. Walker. 2017. Irrigation Water Salinity Influences at Various Growth Stages of Capsicum annuum. Ag Water Management. 179: 246-253.</li><br /> <li>Sharma P., M.K. Shukla, P. Bosland and R. Steiner. 2017. Soil moisture sensor calibration, actual evapotranspiration and crop coefficients for deficit irrigated greenhouse chile. Ag Wat Manag. 179: 81-91.</li><br /> <li>Flores A., M.K. Shukla, B. Schutte, G. Picchioni, and D. Daniel. 2017. Physiologic response of six plant species grown in two contrasting soils and irrigated with brackish groundwater and RO concentrate. Arid land Res. and Manag. Journal. 31:182-203, http://dx.doi.org/10.1080/15324982.2016.1275068.</li><br /> <li>Flores A., M.K. Shukla, D. Daniel, A. Ulery, B. Schutte, G. Pichionni and S. Fernald. 2016. Evapotranspiration Changes with Irrigation Using Saline Groundwater and RO Concentrate. J. Arid Environments. 131:35-45.</li><br /> </ol>

Impact Statements

1. In Idaho, lack of in-season grower willingness to input irrigation data limited the usefulness of the water budget approach. Efforts to automatically integrate field irrigation timing and amount with the Scheduler using either a tipping bucket rain gage or a pressure sensor with cell phone data transfer capability continue, but have not been fully successful to this point. Work on this approach will continue in 2018. Because the sensor / data logger systems are relatively expensive, the level of grower adoption is uncertain. When actual soils, crop and irrigation information was entered into the WSU scheduler, results (indicating when and how much the grower should irrigate, and amount of deep percolation loss) compared well with the soil sensor method. Because the WSU scheduler is free for grower use, development of a method to integrate actual irrigation information into the scheduler should significantly increase the level of grower adoption, and result in better utilization of limited irrigation water. Use of either of these approaches will probably increase in 2018 due to the requirement that water application on approximately 1 million acres of farm land irrigated from ground water sources be reduced by 10-13% in response to settlement of a long-standing lawsuit between the Surface Water Coalition and participating members of the Idaho Ground Water Appropriators, Inc. Requirements for pumping reduction will be fully implemented and enforced in 2018. Based on results of a number of Pacific Northwest irrigation scheduling studies, either of these approaches can play a major role in meeting the requirements of the settlement.

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Report Information

Participants

Steven Evett (Steve.Evett@ARS.USDA.GOV) – USDA ARS, Bushland, Texas; Bradley Rein (BREIN@NIFA.USDA.EDU) – NIFA, USDA; Freddie Lamm (flamm@ksu.edu) – Kansas State University, Isaya Kisekka (ikisekka@ucdavis.edu) - University of California Davis; Amir Haghverdi (amirh@ucr.edu) - University of California, Riverside; Saleh Taghvaeian (saleh.taghvaeian@okstate.edu) - Oklahoma State University; Clinton Shock, Rhuanito Ferrarezi (rferrarezi@ufl.edu) - University of Florida, Pete Jacoby (jacoby@wsu.edu) - Washington State University; Ripendra Awal (riawal@pvamu.edu) – Prairie View A&M University; Howard Neibling (hneiblin@uidaho.edu) - University of Idaho; and Kenneth Shackel (kashackel@ucdavis.edu) - University of California Davis (Zoom)

Brief Summary of Minutes

• The annual meeting was held on December 3, 2018, in the S-7 (Seaside level) room of Long Beach Convention & Entertainment Center in Long Beach, California. The meeting was presided by 2018 Committee Chair Dr. Rhuanito Ferrarezi.


• The venue chosen for the next meeting in 2019 was San Antonio, Texas at ASA, CSSA, and SSSA Annual Meetings on Nov 10-13, 2019. Dr. Steve Evett and Dr. Freddie Lamm will provide support with the society to not have registration fees.


• Amir Haghverdi, Assistant CE Specialist at the University of California Riverside, was elected 2019 secretary for the W3128 group. Dr. Davie Kadyampakeni and Dr. Ripendra Awal become 2019 Committee Chair and Vice-Chair, respectively.


• W3128 Project will expire on September 30, 2019. The new proposal is due in the National Information Management Support System (NIMSS) system by January 15, 2019.


• Bradley Rein (NIFA – USDA) provided NIFA updates. He briefly discussed on the background of new NIFA director Dr. J. Scott Angle and his interest in agricultural production. Dr. Rein also highlighted transition plans (building relocation, personnel challenges) of NIFA briefly. Dr. Rein informed the committee about some funding opportunities: AFRI Water for Food Production Systems (about seven awards), Sustainable Agricultural Systems, Agriculture Systems and Technology (Foundational and Applied Science Program).


• Steve Evett provided ARS updates and state reports were presented by Dr. Ripendra Awal (Texas) and Dr. Amir Haghverdi (California).


• The rest of the meeting was focused on new W4128 grant discussion and writing. All participants were able to contribute in an online document created by Dr. Rhuanito Ferrarezi for proposal writing.


• The committee organized Special Session – W3128: USDA-National Institute of Food & Agriculture Multistate Microirrigation Research Group on December 4 (2:00 p.m.-5:00 p.m.). The session was moderated by Dr. Danny H. Rogers, Oklahoma State University. Following eight papers were presented during the session:
  
  
  
  • Evaporative Loss Differences Between Subsurface Drip Irrigation & Sprinkler Irrigation – Southern High Plains Experience  - Steven R. Evett, USDA-ARS
  
  
  • Direct Root Zone Drip Irrigation to Enhance Precision Deficit Irrigation - Pete Jacoby, Washington State University
  
  
  • Subsurface Drip Fertigation for Site-specific Precision Management of Cotton - Mark Dougherty, Auburn University
  
  
  • Soil Moisture & Nutrient Dynamics in Root Zone of Collard Greens Produced in Different Organic Amendments & Rates - Ripendra Awal, Prairie View A&M University
  
  
  • Potential for Intensification of Maize Production With Subsurface Drip Irrigation - Freddie Ray Lamm, Kansas State University
  
  
  • Citrus Water Use & Soil Moisture Distribution Using Regulation Deficit Irrigation - Davie Mayeso Kadyampakeni, University of Florida
  
  
  • Effect of Irrigation Methods & Plant Densities on Grapefruit Cultivated in Open Hydroponics System - Rhuanito Soranz Ferrarezi, University of Florida Institute of Food and Agriculture Sciences Indian River Research and Education Center
  
  
  • Creation & Adoption of Smart Agriculture Innovations - Clinton C. Shock, Oregon State University Malheur Experiment Station
  
  
  
  

Accomplishments

<p><strong>Alabama</strong></p><br /> <p><strong><em>Objective 1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches. </em></strong></p><br /> <p>Ongoing development of a method to use field soil tension monitoring in soybeans to develop crop coefficients for irrigation scheduling.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 2. </em></strong><strong><em>Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities and</em></strong></p><br /> <p><strong><em>Objective 3. Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</em></strong></p><br /> <p>Compiled seven years of subsurface fertigated cotton yield data in replicated research plot study. Treatments related to timing of fertigated nitrogen. Results presented in 2018 Irrigation Association meeting and being revised for publication 2019.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>California</strong></p><br /> <p><strong>University of California Riverside (Department of Environmental Sciences)</strong></p><br /> <ol><br /> <li><strong>Outputs</strong></li><br /> </ol><br /> <p>Research findings were disseminated via refereed journal publications, conference proceedings, and a number of presentations at national and international meetings (see the publication section below). HYDRUS models have been updated with several new capabilities and options that have been developed for various research projects, which in turn have been published in peer-reviewed journals.</p><br /> <p>&nbsp;</p><br /> <ol start="2"><br /> <li><strong>Activities<br /> </strong>In 2018, we offered two- or three-day short courses on how to use HYDRUS models at a) Czech University of Life Sciences, Prague, Czech Republic, b) Colorado School of Mines, Golden, CO, c) the Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, Peoples Republic of China, d) Tokyo University of Agriculture and Technology, Department of Ecoregion Science, Tokyo, Japan, e) WASCAL Headquarters, Accra, Ghana, NC. About 150 students participated in these short courses.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Meetings attended</strong>:</p><br /> <ol><br /> <li>W-3188 Western Regional Soil Physics Group Meeting, Desert Research Institute, Las Vegas, NV, January 2-4, 2018.</li><br /> <li>CZO/LTER/NEON/ISMC Workshop "Using Observation Networks to Advance Earth&nbsp;System Understanding: State of the&nbsp;Art, Data-Model Integration, and&nbsp;Frontiers",February 13-15, 2018.</li><br /> <li>6th International Conference "HYDRUS Software Applications to Subsurface Flow and Contaminant Transport Problems", University of Tokyo, Tokyo, Japan, September 20, 2018.</li><br /> <li>ISMC (International Soil Modelling Consortium) bi-annual meeting in Wageningen, The Netherlands, November 5-7, 2018.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>HYDRUS Teaching</strong>:</p><br /> <ol><br /> <li>A short course &ldquo;Advanced modeling of water flow and contaminant transport in porous media using the HYDRUS software packages&rdquo; organized by Czech University of Life Sciences, Prague, Faculty of Agrobiology, Food and Natural Resource, Prague, Czech Republic, March 19-21, 2018. Other instructor: M. Th. van Genuchten (20 participants).</li><br /> <li>A short course &ldquo;Modeling Water Flow and Contaminant Transport in Soils and Groundwater Using the HYDRUS Computer Software Packages&rdquo;, Colorado School of Mines, Golden, CO, June 25-27, 2018. Sole instructor (14 participants).</li><br /> <li>A short course &ldquo;Modeling Water Flow and Contaminant Transport in Porous Media Using the HYDRUS and HP1 Software Packages&rdquo;, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, Peoples Republic of China, July 2-4, 2018. Sole instructor (28 participants).</li><br /> <li>A short course &ldquo;Modeling Water Flow and Contaminant Transport in Soils and Groundwater Using the HYDRUS Computer Software Packages&rdquo;, Tokyo University of Agriculture and Technology, Department of Ecoregion Science, Tokyo, Japan, September 18-19, 2018. Other instructors: Dr. Hirotaka Saito (60 participants).</li><br /> <li>A short course &ldquo;Hackathon: Modeling of Irrigation, Water Flow and Nutrient Transport in Soils (using the HYDRUS Software Packages)&rdquo;, WASCAL Headquarters, Accra, Ghana, November 29-30, 2018. Other instructor: Dr. Roland Baatz (30 participants).</li><br /> </ol><br /> <p>&nbsp;</p><br /> <ol start="3"><br /> <li><strong>Short-term Outcomes and Milestones</strong></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 1.</em></strong> <strong><em>Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></strong></p><br /> <p><strong><em>&nbsp;</em></strong></p><br /> <p><strong><em>Objective 2.</em></strong> <strong><em>Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</em></strong></p><br /> <p><em>&nbsp;</em></p><br /> <p>We continue to expand the capabilities of the HYDRUS modeling environment by developing specialized modules for more complex applications that cannot be solved using its standard versions. The standard versions of HYDRUS, as well as its specialized modules, have been used by myself, my students, and my collaborators in multiple applications described below.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong><em>The Use of Hydrus Models to Evaluate Various Irrigation and Fertigation Problems</em></strong><strong> - <em>Agricultural Applications</em></strong></li><br /> <li><strong>Karandish et al.</strong> <strong>(2018)</strong> applied HYDRUS (2D/3D) for predicting the influence of subsurface drainage on soil water dynamics in a rainfed-canola cropping system. The simulation results demonstrated that the groundwater table management can be an effective strategy to sustain shallow aquifers in the subsurface-drained paddy fields during winter cropping.</li><br /> <li><strong>Darzi-Naftchali et al. (2018)</strong> applied the HYDRUS (2D/3D) model to investigate the combined effects of different subsurface drainage systems and water management strategies on water balance, groundwater table, transpiration efficiency, and water use efficiency in paddy fields.</li><br /> <li><strong>Hartmann et al. (2018)</strong> developed a root growth model and implemented it into HYDRUS. The model considers root growth to be a function of different environmental stresses. The effects of temperature in the root growth module was the first part of the newly developed HYDRUS add-on to be validated by comparing modeling results with measured rooting depths in an aeroponic experimental system with bell pepper.</li><br /> <li><strong>Karimov et al.</strong> <strong>(2018)</strong> used HYDRUS-1D to evaluate whether a change in cropping pattern can produce water savings and social gains. The analysis was carried out for the Fergana Valley, Central Asia. Modeling results indicate that replacing alfalfa with winter wheat in the Fergana Valley released significant water resources, mainly by reducing productive crop transpiration when abandoning alfalfa in favor of alternative cropping systems. However, the winter wheat/fallow cropping system caused high evaporation losses from fallow land after harvesting of winter wheat. Double cropping (i.e., the cultivation of green gram as a short duration summer crop after winter wheat harvesting) reduced evaporation losses, enhanced crop output and hence food security, while generating water savings that make more water available for other productive uses.</li><br /> <li><strong>Shelia et al. (2018)</strong> implemented the HYDRUS flow routines into the DSSAT crop modeling system. DSSAT refers to a suite of field‐scale, process‐based crop models that simulate the phenological development of crops, including detailed information about various yield components, from emergence till maturity on the basis of crop genetic properties, environmental conditions (soil, weather) and management options. While the DSSAT system thus far relied on the &ldquo;tipping bucket&rdquo; water balance approach to represent soil hydrologic and water redistribution processes, implementation of the HYDRUS flow routines into DSSAT allows one to use now the more process-based Richards equation to represent these processes.</li><br /> <li><strong>Phogat et al. (2018a)</strong> evaluated soil water and salinity dynamics under sprinkler irrigated almond exposed to a varied salinity stress at different growth stages using both field experiments as well as their analysis using HYDRUS (2D/3D). This study provided a greater understanding of soil water and salinity dynamics under almond irrigated with waters of varying qualities.</li><br /> <li><strong>Phogat et al. (2018b)</strong> used the HYDRUS-1D model to identify the future water and salinity risks to irrigated viticulture in the Murray-Darling Basin, South Australia. Water and water related salinity risks to viticulture were assessed by running the HYDRUS-1D model with 100 ensembles of downscaled daily meteorological data obtained from the Global Climate Model (GCM) for 2020&ndash; The modeling output was evaluated for seasonal irrigation requirements of viticulture, root zone soil salinity at the beginning of the new season, and the average seasonal salinity for all 100 realizations for four 20-year periods. The modeling results indicate that soil salinity at the beginning of the vine season and the average seasonal salinity are crucial factors that may need special management to sustain the viticulture in this region.</li><br /> <li><strong>Kacimov et al. (2018)</strong> revisited the Kornev&rsquo;s irrigation technology and Kidder&rsquo;s free boundary problems using analytical solutions and verified them using HYDRUS.</li><br /> <li><strong>Brunetti et al. (2018)</strong> developed a hybrid Finite Volume &ndash; Finite Element (FV-FE) model that describes the coupled surface subsurface flow processes occurring during furrow irrigation and fertigation. The numerical approach combines a one-dimensional description of water flow and solute transport in an open channel with a two-dimensional description of water flow and solute transport in a subsurface soil domain, thus reducing the dimensionality of the problem and the computational cost. The modeling framework includes the widely used hydrological model, HYDRUS, which can simulate the movement of water and solutes, as well as root water and nutrient uptake in variably-saturated soils. The robustness of the proposed model was examined and confirmed by mesh and time step sensitivity analyses. The model was theoretically validated by comparison with simulations conducted with the well-established model WinSRFR and experimentally validated by comparison with field-measured data from a furrow fertigation experiment conducted in the US.</li><br /> <li><strong>Liu et al. (2019)</strong> developed a coupled model a numerical model simulating water flow and solute transport for a furrow irrigation system, in which surface water flow and solute transport are described using the zero-inertia equation and the average cross-sectional convection-dispersion equation, respectively, while the two-dimensional Richards equation and the convection-dispersion equation are used to simulate water flow and solute transport in soils, respectively. Solutions are computed numerically using finite differences for surface water flow and finite volumes for solute transports in furrow. Subsurface water flow and solute transport equations are solved using the CHAIN_2D code. An iterative method is used to couple computations of surface and subsurface processes. The coupled model was validated by comparing its simulation results with measured data.</li><br /> <li><strong>Karandish and </strong><strong>&Scaron;imůnek (2018)</strong> used the field-calibrated and validated HYDRUS (2D/3D) model to find optimal management scenarios based on the concept of the water footprint (WF), a measure of the consumptive and degradative water use. The scenarios were defined as a combination of different salinity rates (SR), irrigation level s (IL, the ratio of an actual irrigation water depth and a full irrigation water depth), nitrogen fertilization rates (NR), and two water-saving irrigation strategies, deficit irrigation (DI) and partial root-zone drying (PRD).</li><br /> <li><strong>Wongkaew et al. (2018)</strong> used an artificial capillary barrier (CB), which consisted of two layers of gravel and coarse sand, to improve the soil water retention capacity of the root zone of sandy soil for the cultivation of Japanese spinach. The performance of a CB under specific conditions was evaluated using numerical simulations. Wangkaew et al. (2018) (i) evaluated the performance of a CB during the cultivation of Japanese spinach irrigated at different rates and (ii) investigated the effect of the irrigation schedule on root water uptake. Numerical analysis was performed using HYDRUS-1D after the soil hydraulic properties of the CB materials were determined.</li><br /> <li><strong>Saefuddin et al. (2018)</strong> evaluated a ring-shaped emitter made from a standard rubber hose that has been developed and introduced for subsurface irrigation in Indonesia. It is a low-cost irrigation technology based on indigenous materials and skills. To build a ring-shaped emitter of the original design, a rubber hose is bent into a ring shape with a diameter of about 20 cm, and then five 5-mm holes are drilled into it at even intervals. The entire ring-shaped hose is covered with a permeable textile so that water can infiltrate in all directions around the buried emitter. The main objectives of this study thus were 1) to experimentally investigate the water movement around a buried ring-shaped emitter and 2) to numerically evaluate the effect of modifying the design of the ring-shaped emitter on soil water dynamics around the emitter. Numerical simulations were carried out using HYDRUS, one of the most complete packages for simulating variably-saturated water flow in two- or three-dimensional domains.</li><br /> <li><strong>Karandish and </strong><strong>&Scaron;imůnek (2019)</strong> applied the HYDRUS (2D/3D) and SALTMED models to investigate the influence of various water-saving irrigation strategies on maize water footprints. The models were first calibrated and validated based on data collected in a two-year field investigation under five water-saving irrigation treatments: full irrigation, partial root-zone drying at water deficit levels of 55% and 75%, and deficit irrigation at the same levels. While the SALTMED model performed well when simulating crop growth parameters, the HYDRUS (2D/3D) model was more accurate when simulating soil water and solute transport.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol><br /> <li><strong><em>Hydrological Applications</em></strong></li><br /> <li><strong>Szymkiewicz et al. (2018)</strong> simultaneously used the HYDRUS and SWI2 packages for MODFLOW to simulate freshwater lens recharge and the position of the salt/freshwater interface. While the HYDRUS package gives MODFLOW the capability to consider processes in the vadose zone, the SWI2 package is used to represents in a simplified way variable-density flow associated with saltwater intrusion in coastal aquifers.</li><br /> <li><strong>Beegum et al. (2018, 2019)</strong> first updated the HYDRUS package for MODFLOW (HPM) by developing a new methodology to eliminate the error in the determination of the recharge flux at the bottom of the HPM profile and then additionally also implemented solute transport into the HPM. She then successfully tested these two new developments against fully two- or three-dimensional simulations with HYDRUS (2D/3D).</li><br /> <li><strong>Sasidharan et al. (2018a)</strong> conducted numerical and field scale experiments to improve our understanding and ability to characterize the drywell behavior. HYDRUS (2D/3D) was modified to simulate transient head boundary conditions for the complex geometry of the Maxwell Type IV drywell. Falling-head infiltration experiments were conducted on drywells located at the National Training Center in Fort Irwin, California (CA) and a commercial complex in Torrance, CA to determine in situ soil hydraulic properties by inverse parameter optimization.</li><br /> <li><strong>Brunetti et al. (2018a)</strong> investigated the use of different global sensitivity analysis techniques in conjunction with a mechanistic model in the numerical analysis of a permeable pavement installed at the University of Calabria. The Morris method and the variance-based E-FAST procedure were applied to investigate the influence of soil hydraulic parameters on the pavement&rsquo;s behavior. The analysis revealed that the Morris method represents a reliable computationally cheap alternative to variance-based procedures for screening important factors and provides the first inspection of the model. The study was completed by a combined GSA-GLUE uncertainty analysis used to evaluate the model accuracy.</li><br /> <li><strong>Brunetti et al. (2018b)</strong> assessed the information content of aboveground fast-neutron counts to estimate SHPs using both a synthetic modeling study and actual experimental data from the Rollesbroich catchment in Germany. For this, the forward neutron operator COSMIC was externally coupled with the hydrological model HYDRUS-1D. The coupled model was combined with the Affine Invariant Ensemble Sampler to calculate the posterior distributions of effective soil hydraulic parameters as well as the model-predictive uncertainty for different synthetic and experimental scenarios. Measured water contents at different depths and cosmic-ray neutron fluxes were used to assess estimated SHPs.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ul><br /> <li><strong><em>Fate and Transport of Various Substances (Carbon Nanotubes, Viruses, Explosives)</em></strong></li><br /> </ul><br /> <p>With another member of the W3188 group, Scott Bradford we worked on three aspects of the transport of pathogens in the subsurface.</p><br /> <ol><br /> <li><strong>Arthur et al. (2018)</strong> used the HYDRUS-1D model that was modified to consider particle dissolution to evaluate dissolution and transport of energetic constituents from the new insensitive munitions (IM) formulations IMX-101, a mixture of NTO, NQ, and DNAN, and IMX-104, a mixture of NTO, RDX, and DNAN. NTO and DNAN are emerging contaminants associated with the development of insensitive munitions as replacements for traditional munitions. Flow interruption experiments were performed to investigate dissolution kinetics and sorption non-equilibrium between soil and solution phases.</li><br /> <li><strong>Rahmatpour et al. (2018)</strong> investigated the transport and retention of polyvinylpyrrolidone (PVP) stabilized silver nanoparticles (AgNPs, diameter of 40 nm) under saturated and unsaturated conditions in intact columns of two calcareous sandy loam (TR) and loam (ZR) soils. The one-site kinetic attachment model in HYDRUS-1D, which accounted for time- and depth-dependent retention, was successfully used to analyze the retention of AgNPs. The results showed that the degree of saturation had little effect on the mobility of AgNPs through undisturbed soil columns. The results suggested the limited transport of AgNPs in neutral/alkaline calcareous soils under both saturated and unsaturated conditions.</li><br /> <li><strong>Adrian et al. (2018)</strong> conducted packed column experiments to investigate the transport and blocking behavior of surfactant-and polymer-stabilized engineered silver nanoparticles (Ag-ENPs) in saturated natural aquifer media with varying content of silt and clay fraction, background solution chemistry, and flow velocity. Breakthrough curves for Ag-ENPs exhibited blocking behavior that frequently produced a delay in arrival time in comparison to a conservative tracer that was dependent on the physicochemical conditions, and then a rapid increase in the effluent concentration of Ag-ENPs. This breakthrough behavior was accurately described using one or two irreversible retention sites that accounted for Langmuirian blocking on one site.</li><br /> <li><strong>Sasidharan et al. (2018)</strong> investigated the influence of virus type (PRD1 and FX174), temperature (flow at 4 and 20&deg;C), a no-flow storage duration (0, 36, 46, and 70 d), and temperature cycling (flow at 20&deg;C and storage at 4&deg;C) on virus transport and fate in saturated sand-packed columns. The vast majority (84&ndash;99.5%) of viruses were irreversibly retained on the sand, even in the presence of deionized water and beef extract at pH = 11. A model that considered advective&ndash;dispersive transport, attachment, detachment, solid phase inactivation, and liquid phase inactivation coefficients, and a Langmuirian blocking function provided a good description of the early portion of the breakthrough curve.</li><br /> <li><strong>Liang et al. (2019)</strong> investigated the roles of graphene oxide (GO) particle geometry, GO surface orientation, surface roughness, and nanoscale chemical heterogeneity on interaction energies, aggregation, retention, and release of GO in porous media. Calculations revealed that these factors had a large influence on the predicted interaction energy parameters.</li><br /> </ol><br /> <p><strong>&nbsp;</strong></p><br /> <ol><br /> <li><strong><em>Reviews</em></strong></li><br /> <li><strong>Jacques et al. (2018)</strong> reviewed recent adaptations of the HPx module of HYDRUS that have significantly increased the flexibility of the software for different environmental and engineering applications. They provide an overview of the most significant changes of HPx, such as coupling transport properties to geochemical state variables, gas diffusion, transport in two and three dimensions, and the support for OpenMP that allows for parallel computing using shared memory. The authors concluded that HPx offers a unique framework to couple spatial-temporal variations in water contents, temperatures, and water fluxes, with dissolved organic matter and CO2 transport, as well as bioturbation processes.</li><br /> <li><strong>&Scaron;imůnek et al.</strong> <strong>(2018)</strong> reviewed new features of the version 3 of the HYDRUS (2D/3D) computer software package<em>.</em> These new features include a flexible reservoir boundary condition, expanded root growth features, and many new graphical capabilities of the GUI. Mathematical descriptions of the new features are provided, as well as two examples illustrating applications of the reservoir boundary condition.</li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>Invited Presentations</strong>:</p><br /> <ul><br /> <li>Focus presentation "<em>The use of HYDRUS models to evaluate processes in the critical zone</em>" at the CZO/LTER/NEON/ISMC Workshop "Using Observation Networks to Advance Earth&nbsp;System Understanding: State of the&nbsp;Art, Data-Model Integration, and&nbsp;Frontiers",Bolder, Colorado, February 13, 2018.</li><br /> <li>Keynote presentation &ldquo;Recent Developments and Applications of the HYDRUS Software Packages&rdquo; at the workshop "HYDRUS Software Applications to Subsurface Flow and Contaminant Transport Problems", University of Mie, Mie, Japan, September 13, 2018.</li><br /> <li>Keynote presentation &ldquo;Recent and Current Developments and Applications of the HYDRUS Software Packages&rdquo; at 6th International Conference "HYDRUS Software Applications to Subsurface Flow and Contaminant Transport Problems", University of Tokyo, Tokyo, Japan, September 20, 2018.</li><br /> <li>Invited presentation &ldquo;<em>Numerical Modeling of Vadose Zone Processes using HYDRUS and its Specialized Modules</em>&rdquo;, Meiji University, Tokyo, Japan, September 26, 2018.</li><br /> <li>Invited presentation &ldquo;<em>Numerical Modeling of Vadose Zone Processes using HYDRUS and its Specialized Modules</em>&rdquo;, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan, September 28, 2018.</li><br /> </ul><br /> <p>&nbsp;</p><br /> <p><strong>2018 Awarded and Active Grants</strong></p><br /> <p>2015-2020&nbsp;&nbsp;&nbsp; USDA, ARS, Improved Decision Support for Management of Non-traditional Irrigation, 09/30/2015 - 09/29/2020, PI: J. &Scaron;imůnek, $225,000.</p><br /> <p>2016-2019&nbsp;&nbsp;&nbsp; ANR Competitive Grants proposal #3741&nbsp;<em>Optimizing Water Management Practices to Minimize Soil Salinity and Nitrate Leaching in California Irrigated Cropland, </em>PI: L. Wu; CoPIs: K. Bali, D. Haver, B. L. Sanden, and J. &Scaron;imůnek, 04/01/2016-03/31/2019, $299,613.</p><br /> <p>2016-2019&nbsp;&nbsp;&nbsp; ANR Competitive Grants proposal #3771&nbsp;<em>Improving nitrate and salinity management strategies for almond grown under micro-irrigation, </em>PI: P. Brown; CoPIs: M. Kandelous, J. &Scaron;imůnek, S. Grattan, S. Benes, and B. Sanden, 04/01/2016-03/31/2019, $386,112.</p><br /> <p>2016-2019&nbsp;&nbsp;&nbsp; DOD, SERDP, 17 ER02-034 in response to SON Number: ERSON-17-03 Improved Understanding of the Fate and Effects of Insensitive Munitions Constituents; Proposal title "Phototransformation, Sorption, Transport, and Fate of Mixtures of NTO, DNAN, and Traditional Explosives as a Function of Climatic Conditions". A project with Dr. Katerina Dontsova at University of Arizona, Tucson, UCR share is $63,447.</p><br /> <p>2016-2019&nbsp;&nbsp;&nbsp; EPA, USDA-ARS, Interagency Agreement for the project: "Research Support for Watershed and Basin Hydrology and Water Quality in the Arid and Semi-arid Southwest, USA", $200,000. UCR PI: Jiri Simunek; other funding goes to USDA-ARS Tucson and USDA-ARS Riverside.</p><br /> <p>2018-2020&nbsp;&nbsp;&nbsp; USDA-NIFA, "<em>Elucidating Colloidal Facilitated Phosphorus Migration in Soils: Through X-Ray Computed Tomography and Hydrus Modeling</em>",<br /> Drs. Lamba and Srivastava (Auburn University), Dr. Karthikeyan (University of Wisconsin-Madison), Dr. Jiř&iacute; &Scaron;imůnek (University of California Riverside). &nbsp;<br /> Total Budget: $500,00; UCR share $70,005.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>University of California Riverside (Haghverdi Water Management Group)</strong></p><br /> <ol><br /> <li><strong> What was accomplished under the project objectives?</strong></li><br /> </ol><br /> <p>A total of 48 research plots were established at UC ANR SCREC in Irvine, California, and are being prepared for irrigation research trial in 2019. The data collection phase will start from February/March of 2019. The irrigation system was installed in July 2018. Each plot is irrigated by 4 quarter circle (pop-up heads) sprinklers, all four controlled by a common solenoid valve for independent control of each plot. In early August 2018, an Acclima CS3500 smart irrigation controller was installed and all solenoid valves were wired to the controller. In addition, soil moisture sensors (Acclima TDT sensors) were installed at 12 plots and were connected to the irrigation controller for continuous monitoring of soil water status within the turf effective root zone throughout the experiment. The plots were covered with bermudagrass sods in August 2018. Bermudagrass was selected due to its superior resistance to heat, drought, salinity and wear compared to other commonly planted turfgrasses in California. All plots are under full irrigation now for the establishment of turfgrass and we will start the irrigation experiment in early 2019.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong> What opportunities for training and professional development has the project provided?</strong></li><br /> </ol><br /> <p>A two-day workshop was organized in 2018 at UCR consisting of hands-on training, lectures and a field tour. The workshop focused on autonomous urban irrigation management and audience were international visiting students and scholars.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong> How have the results been disseminated to communities of interest?</strong></li><br /> </ol><br /> <p>Our website (ucrwater.com) and twitter account (@ucrwater) were used as the clearinghouse to disseminate the findings of the projects in lay language for a diverse audience. The website had on average multiple hundreds page views per month and the twitter account currently has 107 followers.</p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong> What do you plan to do during the next reporting period to accomplish these goals?</strong></li><br /> </ol><br /> <p>Next steps of the experiment will be to collect soil samples to analyze soil hydraulic properties and soil salinity in the lab, perform an irrigation uniformity test on the plots, to finish instrumentations of the plots, identify the irrigation treatments and calibrate soil moisture sensors if needed, and collect base line infiltration data using SATURO infiltrometer (METER Group, Inc. USA). In addition, two plots with treatment extremes i.e. full irrigation and the highest deficit will be equipped with additional sensors for continues turf and soil monitoring. Pressure switches and/or flow meters will be utilized to precisely record irrigation runtimes and water application on each plot.</p><br /> <p>&nbsp;</p><br /> <p><strong>University of California Davis (Plant Sciences Department) </strong></p><br /> <p><strong>Accomplishments: (Objective 1)</strong></p><br /> <p>A novel method was developed and published describing the use of the pressure chamber to determine stem water potential (SWP) in dormant trees.&nbsp; A grape industry funded (AVF) project was started to develop installation and operation protocols for a novel, micro-tensiometer (MT) device developed at Cornell University, to continuously measure SWP in trees and vines.&nbsp; MT&rsquo;s were installed in five mature grapevines, as well as one almond and one walnut tree, and some of these installations have shown good agreement with pressure-chamber measured SWP for periods of up to 4 months.&nbsp; Young almond tree evapotranspiration (ET) and calculated crop coefficient (Kc) was measured lysimetrically for years 1-4, and compared to the ET and Kc predicted from a recently published young peach tree model.&nbsp; For the first 3 years, measured ET and Kc values were substantially higher (about double) than predicted by the model, and after the first year there was a marked overestimate of the soil component of (E of ET) by the model.&nbsp; By the 4^th (most recent) year, canopy growth had increased so that an individual tree % shaded area and Kc could not be determined, but the maximum midsummer Kc for both year 3 and 4 (about 1.2) was above the published mature (&lsquo;full canopy&rsquo;) almond Kc (1.15).&nbsp; These results indicate that the currently accepted values for young tree Kc and ET are substantial underestimates, and also that the mature almond orchard Kc and ET are also underestimates.&nbsp; A multi-year almond water production function experiment was completed, finding that the yield effects of reduced irrigation have been minimal (reductions of from 5 - 25%, depending on location), despite imposing a relatively wide range of irrigation amounts (from 40-60").&nbsp; A multi-year study was completed to document the long term effects on tree and root health of winter flood irrigations in almond orchards for the purpose of groundwater recharge.&nbsp; No negative effects of applying an additional 24" of water during the dormant season (December/January) have been observed.&nbsp; The 5^th year of an ongoing walnut irrigation test was performed, and demonstrated that plant-based measurements (SWP) could be used to delay the first irrigation in the spring by about 1 month, with no detrimental effects on yield, and evidence was obtained that this practice may improve root health over the long term (years).</p><br /> <p>&nbsp;</p><br /> <p><span style="text-decoration: underline;">Training/Professional development:</span></p><br /> <p>Three MS and one PhD students were trained.&nbsp; Two MS and the PhD student graduated.</p><br /> <p>&nbsp;</p><br /> <p><span style="text-decoration: underline;">Dissemination of results:</span></p><br /> <p>Extension presentations to growers and other industry personnel have been made at the annual almond and walnut conferences, in addition to presentations at grower meetings that have been organized by extension farm advisors.&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong>Plans:</strong></p><br /> <p>The following industry supported projects will be continued: 1) Almond Winter Water Management, 2) Almond Lysimeter (ET), 3) Walnut Early Season Water Management, 4) Microtensiometer development in grapevine and other woody perennials.&nbsp; A new SCRI project (&ldquo;Optimizing Irrigation for Sustainable Production of Almonds, Apples and Grapes&ldquo;) based on the use of the microtensiometer for plant-based irrigation will be submitted.</p><br /> <p>&nbsp;</p><br /> <p><strong>University of California Davis (Irrigation and Water Management Research Group)</strong></p><br /> <p><strong><em>Objective 1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></strong></p><br /> <p><strong>Development of a methodology for estimating of almond water status using artificial neural networks</strong></p><br /> <p>Stem water potential (SWP) is a commonly used method for determining plant water status in tree crops but is labor intensive. To eliminate the necessity for intensive fieldwork, artificial neural networks were designed to predict PWS using easier to measure information such as leaf temperature and microclimatic variables including ambient air temperature, relative humidity, incident radiation, and soil water content (Meyers et al., 2018). To collect these variables, leaf monitors developed by Dhillon et al. (2017) and soil water sensors were installed in an almond orchard. The sensors were interconnected through a wireless mesh network which allowed remote data access. SWP values were taken in the field at midday three times a week during the growing season. The artificial neural networks were trained using the Levenberg-Marquardt algorithm. Compared with multiple linear regression models fitting the same data, the neural networks consistently resulted in better R² values. These results suggest that there is potential for machine learning techniques that use artificial neural networks to model the relationship between environmental conditions and plant water stress, which may be used for predicting acceptable temperature difference from target SWP Microirrigated almond orchards.</p><br /> <p><strong>iCrop Model &ndash;Driven Decision Support</strong></p><br /> <p>We have developed iCrop a novel web-based decision support tool that provides site-specific irrigation scheduling recommendations to growers to tree, vegetable and forage growers in California grower&rsquo;s majority of have switched to microirrigation. iCrop uses crop simulation models to integrate the entire farming system including soil (S), weather (E, environment), genetics (G), and crop production practices (M, management; e.g., irrigation and fertility management practices). Preliminary evaluation of iCrop on corn and alfalfa has demonstrated on to improve yields and water productivity through in-season adaptive management of irrigation schedules.</p><br /> <p><strong><em>Objective 2.</em></strong> <strong><em>Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</em></strong></p><br /> <p><strong>Precision irrigation management by variety in almonds</strong></p><br /> <p>A significant number of almond growers in California have shifted from flood to microirrigation. Almond production in California has unique water issues, including the need for post-harvest irrigation and the presence of different almond varieties in the same orchard with shifted growth stages and water needs as a way to establish effective pollination. Traditionally, farmers have set up their microirrigation systems (double drip or micro sprinklers) to irrigate the entire orchard the same and cannot independently irrigate the different almond tree varieties within the same orchard. My research investigated how to precisely and independently irrigate different varieties without interfering with harvest activities and offset growth stages of the different varieties. We retrofitted the drip irrigation system on a commercial orchard with a wireless system that we used to remotely open and close tree rows of different varieties independently. Preliminary results from the 2018 growing season showed significant differences in yield amount three almond varieties (Non-peril, Butte and Aldrich) at the same irrigation level.</p><br /> <p>&nbsp;</p><br /> <p><strong>Precision fertigation management for processing tomatoes</strong></p><br /> <p>Processing tomato producers in California are faced with several challenges e.g., constrained water supplies due to droughts and institutional policies like SGMA, and the Irrigated Lands Regulatory Program (regulation of nitrate leaching). To optimize profitability under limited water resources, growers need to enhance resource use efficiency through precision irrigation and fertigation. Over 80% of processing tomatoes growers in California have switched from flood to subsurface drip irrigation. In May of 2018 we established a study on a 5 acre subsurface drip irrigation field with automated fertigation and irrigation control by volume using ultrasonic flow meters and a Netafim irrigation controller. The objective of this study was to evaluate the effect of high frequency low concentration fertigation and the low frequency high concentration fertigation on yield of processing tomatoes. Preliminary results indicate that there were no significant differences between high and low frequency fertigation under full irrigation. However, under limited water, sustained deficit irrigation produced lower yields compared to regulated deficit irrigation but increased fruit quality in terms of soluble solute concentration.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 3.</em></strong><strong><em> Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</em></strong></p><br /> <p>We have developed the iCrop webapp that growers can use for implementing specific irrigation scheduling for a variety of irrigation systems including microirrigation.</p><br /> <h2>B. What opportunities for training and professional development has the project provided?</h2><br /> <p>I integrated a module in the irrigation systems and water management upper level undergraduate class that I teach at University of California Davis every year. The enrollment during the spring quarter of 2018 was 16 students. The students were introduced to computer aided design of microirrigation systems using the IRRICAD software.</p><br /> <p>I also trained a group of technocrats from Uzbekistan and Turkmenistan on microirrigation management and shared with them experiences from California.</p><br /> <p>&nbsp;</p><br /> <h2>C. How have the results been disseminated to communities of interest?</h2><br /> <p>We have disseminated our results through journal articles, conference presentations, posters and social media (e.g., UCDIrrigation twitter account).</p><br /> <p>&nbsp;</p><br /> <h2>D. What do you plan to do during the next reporting period to accomplish these goals?</h2><br /> <p>We plan to continue with field experiments on precision irrigation management by variety in almonds, precision fertigation management for processing tomatoes and also continue developing and testing of the iCrop decision support system.</p><br /> <p>&nbsp;</p><br /> <p><strong>Florida</strong></p><br /> <p>&nbsp;</p><br /> <ol><br /> <li><strong>What was accomplished under the project objectives?</strong></li><br /> </ol><br /> <p><strong><em>Objective 1.</em></strong><strong><em> Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></strong></p><br /> <p><em>&nbsp;</em></p><br /> <p><strong>Grapefruit production using different irrigation systems and plant density under open hydroponics</strong></p><br /> <p>Precise irrigation and fertigation management provide a less-limiting environment to roots while minimizing over irrigation and leaching of nutrients. This concept can improve tree growth in the presence of HLB and help optimize water and nutrient use. Higher tree density can increase fruit yield per area under high HLB pressure. We conducted a study to evaluated the efficiency of open hydroponics on &lsquo;Ray Ruby&rsquo; grapefruit production under different irrigation systems and tree density. We tested a combination of rootstocks (Sour orange and US897), tree spacing [standard and high density staggered (HDS)], fertilization (dry granular and fertigation), and irrigation systems (drip and microjet).</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 2.</em></strong><strong><em> Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</em></strong></p><br /> <p><em>&nbsp;</em></p><br /> <p><strong>Round orange production using different dry granular fertilizer blends, irrigation systems and plant density</strong></p><br /> <p>Sweet oranges (<em>Citrus sinensis</em>) are impacted by huanglongbing (HLB), a disease associated with Candidatus <em>Liberibacter asiaticus</em>. The disease is threatening the citrus industry, with devastating effects on fruit production. Higher plant density can increase fruit yield per area under high HLB pressure, maximizing income and extending grove survival until a definite cure is found. This study evaluated the effect of tree planting density, fertilizer type and and irrigation systems on fruit yield and quality. &lsquo;Valencia&rsquo; orange on &lsquo;Kuharske&rsquo; citrange (<em>C. sinensis</em> &times; <em>Poncirus trifoliata</em>) trees were planted in Sept/2013 (2,995 trees in 1.61 ha). We tested three treatments: standard tree spacing (3.8&times;7 m, 357 trees/ha) + dry granular fertilizer + microsprinkler irrigation (one emitter per tree; microsprinkler 50 green nozzle, 16.7 GPH at 20 psi) (Bowsmith, Exeter, CA), high density staggered ([2.7&times;1.5&times;0.9 m]&times;6.1 m, 953 trees/ha) + fertigation + microsprinkler irrigation (one emitter per two trees), and high density staggered + fertigation + drip irrigation (two lines per row; Emitterline 0.58 GPH at 10 psi, 12-inch spacing) (Jain Irrigation), in a complete randomized block design with eight replications.</p><br /> <p>&nbsp;</p><br /> <p><strong>Improving performance of HLB infected trees and root health under partial root zone drying</strong></p><br /> <p>The goal of this project is to improve the performance of HLB infected trees, soil and root health under partial root zone drying in a modified hydroponic system under greenhouse conditions. The following are the specific objectives: a)&nbsp;&nbsp; Investigate the optimum fertilization rate of HLB infected trees; b) Determine canopy development, root density and water use under partial root zone drying in hydroponic systems; c) Compare the performance of biochar and compost in ameliorating soil functions and restoring soil microbial diversity. Three N fertilizer rates include: IFAS recommendation for nonbearing trees (Obreza and Morgan, 2008), 75% of IFAS recommendation and 125% of IFAS recommendation with P and K changed proportionally to N. Each fertilization rate has a soil amendment with 1) biochar, 2) compost, and 3) no amendment (control). Two irrigation rates, 100% evapotranspiration (ET) and 75% ET will be used. This will be a 3 x 3 x 2 factorial experiment replicated 4 times in a randomized complete block design.</p><br /> <p>&nbsp;</p><br /> <p><em>O<strong>bjective 3 Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</strong></em></p><br /> <p><em>&nbsp;</em></p><br /> <p><strong>Evaluation of water and nutrient use efficiency</strong></p><br /> <p>Irrigation systems are designed to maximize crop productivity and optimize uniform water application. The amount of water applied is usually determined by empirical methods, which are based on timers instead of the actual crop requirements. Several technologies have recently been developed looking for alternative methods to improve water management efficiency based on weather and soil sensing methods. One of the most relevant advances are the capacitance sensors, offering a great potential to estimate soil volumetric water content (VWC) and electrical conductivity. We conducted a laboratory study to evaluate the accuracy of data collected from several commercial capacitance sensors and establish a calibration equation for different soil types. Tested treatments were five sandy soils (Pineda, Riviera, Astatula, Candler and Immokalee) divided in two depths (0-30 and 30-60 cm) representing the majority of Florida soils used for citrus production.</p><br /> <p><strong>Idaho</strong></p><br /> <p><strong><em>Objective 1.&nbsp; Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-plant or weather-based approaches.</em></strong></p><br /> <p><strong>&nbsp;</strong></p><br /> <p>A web-based water-budget irrigation scheduling program developed by Dr. Troy Peters, WSU, and a soil sensor based approach were again compared in 3 locations on Eastern Idaho farm fields irrigated by center pivot irrigation systems in 2018. At each location, one pivot used a LESA (Low Elevation Sprinkler Application) sprinkler package while the other pivot used the existing Mid-Elevation Sprinkler Application (MESA) system.&nbsp; Differences in water delivered to the ground resulted in a wider seasonal range of crop root zone soil water content on the Control pivots at all three sites than would normally be observed. Water applied to both the Control and LESA pivots was measured by IDWR-approved flowmeters installed before the 2018 growing season.</p><br /> <p>Four Decagon 10 HS sensors, tipping bucket rain gage and an AgSense data logger with cell phone transmission, and web-based data storage and retrieval were used under each of 6 malting barley pivots. Previous year&rsquo;s work with the Ag Sense loggers used Watermark granular matrix sensors.&nbsp; Although sensor information was generally useful for determining if over-irrigation was occurring, abnormal or &ldquo;odd&rdquo; data readings occurred with sufficient frequency to limit sensor effectiveness for anything beyond overall trends and limit grower confidence in the data.&nbsp; Therefore, the 10HS sensors which worked well in 2017 with Onset data loggers, were used on the AgSense loggers this year.&nbsp; Data quality and appropriate response to wetting and drying events was good and made the information more credible and usable by the farmers.</p><br /> <p>The WSU &ldquo;Irrigation Scheduler Remote&rdquo; program used irrigator-selected soil and crop parameters, AgriMet daily estimated crop ET, and rainfall, and irrigator-input irrigation data to evaluate root zone available soil water and depth of irrigation water required to re-fill the root zone on a daily basis.</p><br /> <p>Soil sensors were installed at 4 depths (6, 12, 18, and 24 inches) on each site to serve as a daily soil water comparison measurement.&nbsp; The AgSense data from the sensors and a tipping bucket rain gage (where available) were transmitted by cell phone link to a website at 30-minute intervals.&nbsp; This information, formatted in a user-defined fashion, was available from any mobile device (cell phone, laptop, desktop,...) that could connect with the website.&nbsp; Pre and post-season soil sampling at 6-inch intervals to 5 feet (or rock) depth along with rain gage data provided directly-measured water budget information.</p><br /> <p><strong>Kansas </strong></p><br /> <p><strong><em>Objective 1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></strong></p><br /> <p>In a two year irrigation scheduling study (2016-2017), measured crop water use (sum of irrigation, precipitation, and the change in ASW) compared well with the weather-based calculation on crop evapotranspiration (ETc). Available soil water (ASW) at planting and harvest varied to a much greater degree than did grain yield (&asymp;13.4 vs. 5.4%) implying that the ASW levels were sufficient to prevent yield reductions. Results from an SDI (subsurface drip irrigation) crop intensification study with corn that was initiated in 2017 were summarized in a paper present at the Irrigation Association technical conference. In this study greater corn grain yield and crop water productivity were obtained through appropriate hybrid selection and through increasing plant density.&nbsp; Yield was not affected by irrigation levels from 85 to 115% of full irrigation, but water productivity was greatest at the lowest irrigation level (0.85 ET). This study will be continued in 2019.</p><br /> <p><strong><em>Objective 2.</em></strong><strong><em> Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</em></strong></p><br /> <p>Drafting of revisions to several extension publications concerning subsurface drip irrigation (SDI) concerning design, management and maintenance continued in 2018.&nbsp;&nbsp; Two extension publications were completed with one presenting an overview of how SDI is being implemented in Kansas and the second publication outlining the minimum component requirements for successful systems. A study to examine potassium fertilization with SDI for corn was continued in 2018. Results from two years of a three year study comparing precision mobile drip irrigation (PMDI) with SDI for corn at KSU-NWREC has not shown grain yield or water use differences. A field study examining precision mobile drip irrigation (PMDI) where driplines are attached to a moving center pivot platform initiated in 2015 at the KSU Southwest Research-Extension Center at Garden City, Kansas was continued in 2018.&nbsp;</p><br /> <p><strong><em>Objective 3.</em></strong><strong><em> Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</em></strong></p><br /> <p>Several presentations were made at the regional Central Plains Irrigation Conference along with two presentations at the annual international meeting of the American Society of Agricultural and Biological Engineers (ASABE) and one presentation at the Irrigation Association (IA) technical conference.</p><br /> <p>&nbsp;</p><br /> <p><strong>What opportunities for training and professional development has the project provided?</strong></p><br /> <p>A PhD student at SWREC completed work evaluating irrigation application technologies, specifically looking at potential improvements with precision mobile drip irrigation (PMDI).</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>How have the results been disseminated to communities of interest??</strong></p><br /> <p>Results have been presented to lay audiences at KSU field days, at a regional multistate meeting, and at three international conferences.&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong>What do you plan to do during the next reporting period to accomplish these goals?</strong></p><br /> <p>Field studies will be continued during the coming year.&nbsp; Presentations will be offered at regional and international meetings.&nbsp;</p><br /> <p>&nbsp;</p><br /> <p><strong>Target audience</strong></p><br /> <p>Producers ranging from large, technologically savvy operations to small, part-time or hobby farming operations. Technical service providers such as USDA-NRCS working to improve irrigation and salinity management on regional, state and national scales. Community of scientists and extension specialists in Kansas and also regional, national and international colleagues, particularly for those with semi-arid summer precipitation pattern. Water managers and regulators within the state and region. Policymakers at the local (e.g., GMDs and LEMAs), state (e.g., State agencies and legislators) and national (Federal agencies and Congress) levels. Rural and community interests and foundations.</p><br /> <p><strong>New Mexico</strong></p><br /> <p><strong><em>Objective 1. </em></strong><strong><em>Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></strong></p><br /> <p>Development and Evaluation of Soil-Based Irrigation Scheduling: We continued to calibrate the soil moisture content sensor to measure the moisture content, soil temperature, and soil salinity for water, solute and energy transport through soil. We are currently comparing Hydra, 5TE and TEROS 12. These probes are also used to schedule irrigation for the growing Pecan. A new low cost <em>datalogger</em><em> with wireless transmission capability is developed and tested.</em></p><br /> <p><em>&nbsp;</em></p><br /> <p><strong><em>Objective 2.</em></strong> <strong><em>Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</em></strong></p><br /> <p>&nbsp;</p><br /> <p>A field experiment in Brackish Groundwater National Desalination Research Facility is currently underway. We are growing halophytes using brackish groundwater and concentrate and also looking at soil property changes. Similar experiments are underway for Chile and Pecan.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>Milestone</strong></p><br /> <p>A low cost datalogger with wireless capability is developed that can substantially reduce costs of soil water content data collection.</p><br /> <p><strong>Funding</strong></p><br /> <ul><br /> <li>USDA Hatch grant</li><br /> <li>Nakayama Chair Endowment</li><br /> <li>WRRI-BOR Cooperation grants</li><br /> <li>BOR S&amp;T grant</li><br /> <li>Cochran Grant</li><br /> </ul><br /> <p><strong>Oklahoma</strong></p><br /> <p><strong><em>Objective 1. Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></strong></p><br /> <p>&nbsp;</p><br /> <p>A multi-state (OK, TX, and KS) project on promoting sensor-based technologies to improve irrigation scheduling was continued during the reporting period. As part of this project, canopy temperature and soil moisture sensors were installed at the Oklahoma Panhandle Research and Extension Center near Goodwell, OK, where corn and sorghum plots receive variable levels of irrigation application using a subsurface drip irrigation (SDI) system. The goal is to investigate how these two different types of irrigation scheduling approaches interact and how they can be utilized in managing SDI systems. In addition, soil moisture probes were installed at six other locations in cooperation with local growers. Sensors were evaluated for their accuracy, sensitivity to irrigation applications, and usefulness in improving irrigation scheduling. One challenge in using sensors for irrigation scheduling under SDI is sensor placement, since water movement is not as uniform as under flood or sprinkler systems. To further investigate this challenge additional sensors were installed at different depths and distances from SDI tapes at one site near Hollis in southwest Oklahoma. Our team is going through data quality control and will soon initiate data analysis. We anticipate additional years and sites are required before any conclusions can be made on best management practices for sensor installation under SDI.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 2.</em></strong><strong><em> Develop microirrigation designs and management practices that can be appropriately scaled to site-specific characteristics and end-user capabilities.</em></strong></p><br /> <p>&nbsp;</p><br /> <p>Nothing to report.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 3.</em></strong><strong><em> Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</em></strong></p><br /> <p>&nbsp;</p><br /> <p>Dissemination of information on adoption of microirrigation systems and advanced methods of irrigation scheduling was accomplished by presenting at numerous field days, meetings, workshops, and in-service trainings.</p><br /> <p><span style="text-decoration: underline;">&nbsp;</span></p><br /> <p><span style="text-decoration: underline;">Presentations (advisees are underlined):</span></p><br /> <ul><br /> <li><span style="text-decoration: underline;">Datta S,</span> Taghvaeian S (2018) Performance of soil moisture sensors under field conditions. ASABE Annual International Meeting. Jul. 29-Aug. 1, 2018; Detroit, MI.</li><br /> <li><span style="text-decoration: underline;">Masasi B</span>, Taghvaeian S, Gowda P, Warren J, Marek G (2018) Simulating soil water content, evapotranspiration and yield of variably irrigated grain sorghum using AquaCrop. ASABE Annual International Meeting. Jul. 29-Aug. 1, 2018; Detroit, MI.</li><br /> <li>Taghvaeian S (2018) Sensor technologies for improving agricultural water management. Oklahoma Water Research Advisory Board Meeting. Jul. 18, 2018; Oklahoma City, OK.</li><br /> <li>Taghvaeian S, <span style="text-decoration: underline;">Datta S</span> (2018) Evaluating the performance of soil moisture sensors for irrigation management. World Environmental &amp; Water Resources Congress. Jun. 3-7, 2018; Minneapolis, MN.</li><br /> <li>Taghvaeian S (2018) Irrigation studies at Oklahoma State University. Science and Data in Action Panel. The Ogallala Summit. Apr. 9-10, 2018; Garden City, KS.</li><br /> <li>Taghvaeian S (2018) Using soil moisture sensors to improve irrigation. Oklahoma Irrigation Conference. Mar. 8, 2018; Weatherford, OK.</li><br /> <li>Taghvaeian S (2018) Getting the most from your water: Effective irrigation. Oklahoma Farmers Market Conference and Expo. Feb. 22, 2018; Oklahoma City, OK.</li><br /> <li>Taghvaeian S (2018) Soil moisture sensors. High Plains Irrigation Conference. Feb. 7, 2018; Amarillo, TX.</li><br /> <li>Taghvaeian S, <span style="text-decoration: underline;">Datta S</span>, Boman R (2018) Utilizing sensor technologies to evaluate and improve cotton irrigation management. Beltwide Cotton Conference. Jan. 3-5, 2018; San Antonio, TX.</li><br /> <li><span style="text-decoration: underline;">Datta S</span>, Taghvaeian S, <span style="text-decoration: underline;">Stivers J</span>, Ochsner T, Moriasi D (2017) Performance evaluation of soil moisture sensors under field conditions. 38^th Annual Oklahoma Governor&rsquo;s Water Conference &amp; Research Symposium. Oct. 31-Nov. 1, 2017; Norman, OK.</li><br /> <li><span style="text-decoration: underline;">Masasi B</span>, Taghvaeian S, Gowda P, Warren J, Marek G (2017) Assessment of the AquaCrop model for simulating soil water content, evapotranspiration and yield of grain sorghum. 38^th Annual Oklahoma Governor&rsquo;s Water Conference &amp; Research Symposium. Oct. 31-Nov. 1, 2017; Norman, OK.</li><br /> </ul><br /> <p>&nbsp;</p><br /> <p><span style="text-decoration: underline;">Educational material:</span></p><br /> <ol><br /> <li>Taghvaeian S (2018) Comparing pivot &amp; subsurface drip irrigation. Available at: <a href="https://youtu.be/-ANCaJJwUXE">https://youtu.be/-ANCaJJwUXE</a></li><br /> </ol><br /> <p>&nbsp;</p><br /> <p><strong>Oregon</strong></p><br /> <p><strong>Non-Technical Summary</strong></p><br /> <p>Broad expansion of microirrigation is needed. Unless timely action is taken, it is anticipated that water supply and water quality related crises will affect economies and resources of national and international importance. Microirrigation can reduce the waste of water to a negligible amount and reduce the transport of contaminants to surface water and groundwater. Irrigation events can be fine-tuned to spoon feed water and nutrients just in time to minimize plant water stress. Microirrigation can optimize crop production (more crop per drop) and in many cases, increase the quality of agricultural products. Successful experimental microirrigation results will be scaled up to commercial size through this project. Microirrigation information will be transferred effectively to growers through many venues.</p><br /> <p><strong>&nbsp;</strong></p><br /> <p><strong>What was accomplished under these goals?</strong></p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 1.</em></strong> <strong><em>Develop robust and appropriately-scaled methods of irrigation scheduling using one or more soil-, plant- or weather-based approaches.</em></strong></p><br /> <p><span style="text-decoration: underline;">Potatoes</span>: In 2018 we are carefully compared potato irrigation scheduling based on soil moisture sensors (soil water tension, SWT) with irrigation scheduling based on estimated crop evapotranspiration.&nbsp; These efforts were completed for two potato varieties grown with both sprinkler and drip irrigation.&nbsp; All treatment combinations were replicated 6 times. The irrigation scheduling techniques provided similar results.&nbsp; The potato variety &lsquo;Clearwater Russet&rdquo; produced 44 tons per acre under drip irrigation using crop evapotranspiration irrigation scheduling.</p><br /> <p><span style="text-decoration: underline;">Vineyards</span>:&nbsp; Soil-based measurements of soil water tension (SWT) were compared with soil water content, plant water potential, and crop evapotranspiration in drip-irrigated vineyards. The ideal amount and timing (trajectories) of water stress (as measured by soil, plant, or weather data) are being studied for various cultivars, weather patterns, and sites. In Oregon we seek to measure the trajectories of stress. Modification of the stress trajectory holds the promise of better water use efficiency, protection of water quality, optimization of product quality, and the realization of providing a better return on vineyard investment. The approach is to collect and evaluate automated data that is interpreted and provided in real time to growers.</p><br /> <p><span style="text-decoration: underline;">Automation of data collection and delivery.</span> The automated approach to collect SWT data in vineyards (above) was tested on onion, potato, quinoa, tomato, skullcap, and stevia in 2018.</p><br /> <p><span style="text-decoration: underline;">Seed production of native plants</span> In Oregon fixed irrigation schedules are being compared to soil- and weather-based scheduling for seed production from native plants. Plant species required 0 to 200 mm of supplemental irrigation per year to maximize seed yield. For a given species, yield responses to irrigation varied substantially by year. We have determined that accounting for rainfall during and prior to seed production improves the accuracy of estimating the amount of irrigation required.&nbsp; Species differ in the preceding time interval where precipitation needs to be counted against the irrigation requirement.&nbsp; In 2018 SWT measurements were also collected in a portion of the seed production plots for comparison.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 2.</em></strong> <strong><em>Develop microirrigation designs and management practices that can be appropriately scaled to site- specific characteristics and end-user capabilities.</em></strong></p><br /> <p><span style="text-decoration: underline;">Delivery of herbicides.</span> Herbicides were applied through the drip irrigation system in the hopes of achieving better control of yellow nutsedge. Outlook herbicide applied through drip irrigation was successful in helping to control yellow nutsedge.&nbsp; This work is designed to expand the labeled use of drip-applied Outlook herbicide to control yellow nutsedge.</p><br /> <p><span style="text-decoration: underline;">Delivery of fungicides.</span> Fungicides were applied through the drip system to try to obtain better control of root fungi. Pink root and plate rot were not significant problems in the onion fields used for the trials and the products tested were not beneficial.</p><br /> <p><span style="text-decoration: underline;">Adaptation of drip irrigation for potato production</span> Potato production is generally conducted with sprinkler irrigation. In the US drip irrigation has not been cost effective in comparison to sprinkler irrigation. We sought to change the drip irrigation configuration so that the drip irrigation system could be more efficiently utilized.</p><br /> <p>&nbsp;</p><br /> <p><strong><em>Objective 3.</em></strong><strong><em> Develop technology transfer products for a diversity of stakeholders to promote adoption of microirrigation.</em></strong></p><br /> <p>In objective 1 above, the automatic collection, evaluation, and deliver of soil and weather data is described. The goal was to interpret and deliver results, predictions, and projections in real time to growers' smart phones and laptops based on growers' demands. Growers are gaining real time access to information from their fields for water management decision making. These emerging tools and technology for growers have the potential to simultaneously optimize economic outcomes and minimize the losses of water and nutrients.</p><br /> <p>&nbsp;</p><br /> <p><strong>What opportunities for training and professional development has the project provided?</strong></p><br /> <p>Undergraduate students were trained in research protocols and learned about crop irrigation and management.</p><br /> <p>&nbsp;</p><br /> <p><strong>How have the results been disseminated to communities of interes

Publications

<p><strong>California</strong></p><br /> <p><strong>University of California Riverside</strong></p><br /> <ol><br /> <li>Karandish, F., A. Darzi-Naftchali, and J. &Scaron;imůnek, Application of HYDRUS (2D/3D) for predicting the influence of subsurface drainage on soil water dynamics in a rainfed-canola cropping system, <em>Irrigation and Drainage Journal</em>, <em>67</em>, Supplement 2, 29-39, doi: 10.1002/ird.2194, 2018.</li><br /> <li>Hartmann, A., J. &Scaron;imůnek, K. Aidoo, S. J. Seidel, and N. Lazarovitch, Implementation and application of a root growth module in HYDRUS, <em>Vadose Zone Journal</em>, <em>17</em>(1), 170040, 16 p., doi: 10.2136/vzj2017.02.0040, 2018.</li><br /> <li>In May-December&nbsp;2018, this&nbsp;<strong>highly cited paper</strong>&nbsp;received enough citations to place it in the top 1% of the academic field of&nbsp;Environment/Ecology&nbsp;based on a highly cited threshold for the field and publication year.</li><br /> <li>Darzi-Naftchali, A., F. Karandish, and J. &Scaron;imůnek, Numerical modeling of soil water dynamics in subsurface drained paddies with midseason drainage or alternate wetting and drying management, <em>Agricultural Water Management</em>, <em>197</em>, 67-78, doi: 10.1016/j.agwat.2017.11.017,</li><br /> <li>Arthur, J. D., N. W. Mark, S. Taylor, &Scaron;imůnek, M. L. Brusseau, and K. M. Dontsova, Dissolution and transport of insensitive munitions formulations IMX-101 and IMX-104 in saturated soil columns, <em>Science of Total Environment</em>, <em>624</em>, 758-768, doi: 10.1016/j.scitotenv.2017.11.307, 2018.</li><br /> <li>&Scaron;imůnek, J., Th. van Genuchten, and R. Kode&scaron;ov&aacute;, Thematic issue on HYDRUS applications to subsurface flow and contaminant transport problems, <em>Journal of Hydrology and Hydromechanics</em>, <em>66</em>(2), 129-132, doi: 10.1515/johh-2017-0060, 2018.</li><br /> <li>&Scaron;imůnek, J., M. &Scaron;ejna, and M. Th. van Genuchten, New features of the version 3 of the HYDRUS (2D/3D) computer software package<em>, Journal of Hydrology and Hydromechanics</em>, <em>66</em>(2), 133-142, <strong>doi</strong><strong>: 10.1515/johh-2017-0050,</strong></li><br /> <li>Karimov, K., M. A. Hanjra, J. &Scaron;imůnek, and M. Avliyakulov, Can a change in cropping pattern produce water savings and social gains: A case study from the Fergana Valley, Central Asia, <em>Journal of Hydrology and Hydromechanics</em>,<em> 66</em>(2), 189-201, <strong>doi</strong><strong>: </strong>10.1515/johh-2017-0054, 2018.</li><br /> <li>Jacques, D., J. &Scaron;imůnek, D. Mallants, and M. Th. van Genuchten, The HPx software for multicomponent reactive transport during variably-saturated flow: Recent developments and applications<em>, Journal of Hydrology and Hydromechanics</em>, <em>66</em>(2), <strong>211-226, </strong><strong>doi</strong><strong>: 10.1515/johh-2017-0049,</strong> 2018<em>.</em></li><br /> <li>Shelia, V., &Scaron;imůnek, K. Boote, and G. Hoogenbooom, Coupled DSSAT and HYDRUS-1D for simulations of soil water dynamics in the soil-plant-atmosphere system, <em>Journal of Hydrology and Hydromechanics</em>, <em>66</em>(2), 232-245, doi: 10.1515/johh-2017-0055, 2018.</li><br /> <li>Szymkiewicz, A., A. Gumuła-Kawęcka, J. &Scaron;imůnek, B. Leterme, S. Beegum, B. Jaworska-Szulc, M. Pruszkowska-Caceres, W. Gorczewska-Langner, R. Angulo-Jaramillo, and D. Jacques, Simulation of freshwater lens recharge and salt/freshwater interfaces using the Hydrus and SWI2 packages for Modflow, <em>Journal of Hydrology and Hydromechanics</em>, <em>66</em>(2), 246-256, doi: 2478/johh-2018-0005, 2018.</li><br /> <li>Phogat, V., T. Pitt, J. W. Cox, J. &Scaron;imůnek, and M. A. Skewes, Soil water and salinity dynamics under sprinkler irrigated almond exposed to a varied salinity stress at different growth stages, <em>Agricultural Water Management</em>, <em>201</em>, 70-82, doi: 10.1016/j.agwat.2018.01.018, 2018a.</li><br /> <li>Phogat, V., J. W. Cox, and &Scaron;imůnek, Identifying the future water and salinity risks to irrigated viticulture in the Murray-Darling Basin, South Australia, <em>Agricultural Water Management</em>,<em> 201</em>, 107-117, doi: 10.1016/j.agwat.2018.01.025, 2018b.</li><br /> <li>Rahmatpour, S., M. R. Mosaddeghi, M. Shirvani, and &Scaron;imůnek, Transport of silver nanoparticles in intact columns of calcareous soils: The role of flow conditions and soil texture, <em>Geoderma</em>, <em>322</em>, 89-100, doi: 10.1016/j.geoderma.2018.02.016, 2018.</li><br /> <li>Adrian, Y. F., U. Schneidewind, S. A. Bradford, &Scaron;imůnek, T. M. Fernandez-Steeger, and R. Azzam, Transport and retention of surfactant- and polymer-stabilized engineered silver nanoparticles in silicate-dominated aquifer material, <em>Environmental Pollution</em>, <em>236</em>, 195-207, doi: 10.1016/j.envpol.2018.01.011, 2018.</li><br /> <li>Kacimov, A., Obnosov, and J. &Scaron;imůnek, Steady flow from an array of&nbsp;subsurface emitters: Kornev&rsquo;s irrigation technology and Kidder&rsquo;s free boundary problems revisited, <em>Transport in Porous Media</em>, <em>121</em>(3), 643-664, doi: 10.1007/s11242-017-0978-x, 2018.</li><br /> <li>Brunetti, G., J. &Scaron;imůnek, M. Turco, and P. Piro, On the use of global sensitivity analysis for the numerical analysis of permeable pavements, <em>Urban Water Journal</em>, <em>15</em>(3), 269-275, doi: 1080/1573062X.2018.1439975, 2018.</li><br /> <li>Sasidharan, S. A. Bradford, J. &Scaron;imůnek, B. DeJong, and S. R. Kraemer, Evaluating drywells for stormwater management and enhanced aquifer recharge, <em>Advances in Water Resources</em>, <em>116</em>, 167-177, doi: 10.1016/j.advwatres.2018.04.003, 2018.</li><br /> <li>Brunetti, G., J. &Scaron;imůnek, and E. Bautista, A hybrid finite volume-finite element model for the numerical analysis of furrow irrigation and fertigation, <em>Computers and Electronics in Agriculture</em>, <em>150</em>, 312-327, doi:1016/j.compag.2018.05.013, 2018.</li><br /> <li>Karandish, F., and J. &Scaron;imůnek, An application of the Water Footprint concept to optimize the production of crops irrigated with saline water: Scenario assessment with HYDRUS, <em>Agricultural Water Management</em>, <em>208</em>, 67-82, 2018.</li><br /> <li>Wongkaew, A., H. Saito, H. Fujimaki, and J. &Scaron;imůnek, Numerical analysis of soil water dynamics in a soil column with an artificial capillary barrier growing leaf vegetables, <em>Soil Use and Management</em>, <em>34</em>, 206-215, doi: 10.1111/sum.12423, 2018.</li><br /> <li>Beegum, S., J. &Scaron;imůnek, A. Szymkiewicz, K. P. Sudheer, and I. M. Nambi, Updating the coupling algorithm between HYDRUS and MODFLOW in the &lsquo;HYDRUS Package for MODFLOW&rsquo;, Technical Note, <em>Vadose Zone Journal</em>, <em>17</em>(1), 180034, 8 p., doi: 10.2136/vzj2018.02.0034, 2018.</li><br /> <li>Sasidharan, S., A. Bradford, J. &Scaron;imůnek, and S. Torkzaban, Minimizing virus transport in porous media by optimizing solid phase inactivation, <em>Journal of Environmental Quality</em>, <em>47</em>(5), 1058-1067, doi: 10.2134/jeq2018.01.0027, 2018.</li><br /> <li>Saefuddin,, H. Saito, and J. &Scaron;imůnek, Experimental and numerical evaluation of a ring-shaped emitter for subsurface irrigation, <em>Agricultural Water Management</em>, <em>211</em>, 111-122, doi: 10.1016/j.agwat.2018.09.039, 2019.</li><br /> <li>Liang, Y., S, A. Bradford, J. &Scaron;imůnek, and E. 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Impact Statements

1. During 2015, a growing season during which record setting heat and drought was recorded, we demonstrated the ability to sustain the vigor of vineyards on irrigation rates that were only 30 to 15 percent of commercial rates using traditional surface drip irrigation. Production rates were 75 to 70 percent less than that of full commercial rates of irrigation during 2015 and slightly less than those rates during the second consecutive year of season-long deficit irrigation. During 2017, soil water content to a depth of 8.5 ft. depth was twice as high as during the previous two growing seasons. This factor, together with an extended period of cool wet weather, deferred the first irrigations to be delayed until late June. Treatment effects for our levels and types of irrigation delivery were not significantly different from full commercial rates of surface drip in terms of harvest fruit production and quality of fruit. The 2018 growing season was similar to the 2017 season. Our multi-disciplinary team has also seen potential for using remote sensing to monitor plant water stress in vineyards. These techniques have shown potential to aid in more effective irrigation scheduling.

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