Brief Summary of Minutes of Annual Meeting

Wednesday October 22, 2008 The meeting of the W-1128 group started at 8:00 am at the facilities of NRCS at Portland, Oregon. Dr. Dana Porter presided the meeting. All the participants presented themselves. Dr. LeRoy Daugherty, Administrative Advisor of the W-1128 group, provided copies of several documents which included copies of the current project, last years activities accomplished report, peer review guideline for proposal of new projects, template of the termination report, and project proposal sections. Dr. Bradley Rein made a presentation of some of the changes in the current Farm Bill approved by Congress. He mentioned that the bill includes 6 research divisions which are: 1) Renewable energy, natural resources and environment, 2) Food safety, nutrition and health, 3) Plant health, and production of plant products, 4) Animal health and production of animal products, 5) Agricultural systems and technology, and 6) Agricultural Economics and rural communities. The current W-1128 project falls in division number 5. The current CSREES office will be restructured and become part of the National Institute of Food and Agriculture (NIFA) and will be established on October 1, 2009. He mentioned that there will be mandatory funding for research in the following areas: 1) Specialty crops research initiative, 2) Organic research, and 3) Beginning farmers & rancher program. Of the three mandatory funding areas only specialty crops requires 1:1 matching funds. The website that includes all the information on changes in the Farm Bill is www.csrees.usda.gov. One of the issues that Dr. Rein mentioned is the probability that less funds will be assigned for research than for extension. All proposals must be submitted through website grants.gov and the old program PureEdge will no longer will be used and will be changed for ADOBE. Dr. Rein finished his presentation. Then the members of the nomination committee for the new secretary of the group were selected. The committee was constituted by Dr. Mick ONeill, Dr. Kenneth Shackel, and Dr. Freddie Lamm. The group initiated the discussion on 2008 milestone. Dr. Lamm indicated that Dr. Mahbub Alam analyzed the results of the survey conducted at Kansas. KS and CO are the only states that participated in the survey. Dr. Larry Schwankl indicated that he completed the ongoing efforts on iron clogging. Doctor Lamm mentioned that he thinks that Dr. Gary Clark will no longer be part of the committee because he is in administrative functions. Dr. Howard Neibling and Dr. Clint Shock agreed to work on drip tape placement. Larry Schwankl mentioned that he decided to change the redaction of a hand book of maintenance of microirrigation systems for a website. Dr. Shackel discussed a milestone regarding evapotranspiration (ET). He found a huge variation in actual water applied among experiments when comparing microirrigation scheduling by using plant or soil-based methods and calculated ETc. There was a discussion among participants about the conformability of crop coefficients. Dr. Ali Fares suggested that the group should create guidelines to work with microirrigation because of the variation observed among ET and actual AT applied by microirrigation. Larry Schwankl suggested that the new project should work on the comparison of subsurface drip irrigation (SDI) and ET function, yield reduction and variation. Dr. Craig Stanley mentioned that pesticide application effectiveness should be also included in the next project. He mentioned that the replacement for methyl bromide may be applied by the microirrigation system. Dr. Lamm mentioned that the group must decide if the objectives of the next project should be written broadly, to facilitate the inclusion of everybodys research work, or be narrow just to include the research of persons participating actively in the W-1128. The group decided to write the objectives as narrowly as possible. If someone wants to join the group they should work within those objectives. Dr. Schwankl suggested that research effort should be stated by state groups in a specific topic. Dr. Lamm indicated that he needs help on literature review for the project in research topics he is not familiar with. He also mentioned the possibility of the addition of an economist to the W-1128. Dr. Clarence Prestwich mentioned that one of his colleagues may be interested in joining the group. There was a discussion about design and management of microirrigation systems. Dr. Schakel thinks that management limits design. Dr. Stanley pointed out that residential microirrigation is becoming important (landscaping microirrigation, use of gray water, etc.) Dr. Stanley and Dr. Howard Neibling agreed to work on that topic. The group discussed the effectiveness of soil moisture sensors. Dr. Neibling proposed to put together an extension publication on soil moisture sensor selection, installation and use. Someone indicated that the group may work on a website dealing with pros and cons of soil moisture sensors available on the market including a section on management for specific crops. Dr. Schakel indicated that he and other researchers got funded in a specialty crop proposal in which are using surface energy balances. They proposed to create a website showing N and water stressed fields (geo-spatial site specific.) Dr. Schakel and Dr. Manoj K. Shukla agreed to work on developing that kind of technology in the W-1128 group with the help of Ted Sammis. Dana Porter mentioned that an outcome of the project could be developing a workshop with producers, providers and crop consultants in that kind of technology. She mentioned that a product that fits the geo-spatial site specific research is the work that Dr. ONeill and Dr. Shock are working on. This is ET based microirrigation scheduling of poplar on upper and lower ends of the mountains. Water requirement determination research topics were discussed. The important issue is how to express water requirement (allocation, and water application by irrigation system) on melon, cotton, poplar, landscape plants, biofuel, oil seed crops and forage seed crops. Dr. Schakel insisted that the water requirement is given by the Kc values. If the reference ET is known then crop coefficients can be used. Ali mentioned that crop coefficients are site specific. Dr. Schakel said that the whole concept of crop coefficient is questioned. Design, management and maintenance issues were discussed. Dr. Schwankl said that not much can be done with clogging. He suggested creating a maintenance website (extension efforts on acid injection, chlorination, filtration, etc.). The issue of deficit irrigation was brought up by Dr. Lamm. There is a difference between deficit irrigation and regulated deficit irrigation (RDI). Water application in RDI is reduced for a period of time to increase or maintain yield and profit or reduce water use. The group is not clear if the topic regarding maintaining adequate water quality should be eliminated. The group decided to work just in extension activities in urban microirrigation. Nutrient management, soil additives and pesticides applications  fertigation application (protecting water quality, optimizing, nutrient management in production, etc.) Microirrigation with non-potable water - food safety, security related concern, use of gray water (house waste water, shower, laundry), reclaimed waste water. Waste water management is a multistate type of project because it is expensive to work with. Pathogen transport. October 23, 2008 The nomination committee selected Dr. Amy L Kaleita from Iowa State University as the new secretary of the group and the following year it will be Dr. Manoj K. Shukla from New Mexico State University. The next year meeting must be after October 1, 2009 because there cannot be two meetings in the same fiscal year. Dr. Lamm mentioned that in 2010 the meeting could be together with the Irrigation Association meeting. The group decided that next years meeting will be in Puerto Rico from 16-18 November 2009 and Dr. Román Paoli will be in charge of all local arrangements. Dr. Schakel, Dr. Neibling and Dr. Lawrence Parson will be working in the maintenance website. Dr. Daugherty mentioned that the Director of the Agricultural Experiment Station must add researchers through Appendix E. Dr. Shackel began with the state reports. In synthesis he mentioned that applied water to almonds saves about 5 inches from 40 inches compared with ETc. He pointed out that the group agrees that ET will be expressed as unit area instead of wetted or irrigated area. Tall grass reference crop coefficients are about the same than short grass reference crop coefficients. The group left for the field trip about 10:00 am. October 24, 2008 Dr. Shackel continued with state reports. He presented a plot with the relationship between seasonal water requirements of several crops in various environments such as soybean and corn and actual water applied. In soybean, actual water applied was less than 0.3 fraction of ET whereas in corn it was 0.7. To estimate the relationship between ETc and ET0 some assumptions have to be made such as 100% ET and 100% yield and that crop the is not affected by diseases and other yield reducing factors beside water status. Dr. Lamm and Dr. Porter submitted a proposal for SDI education in Texas and Kansas dealing with the protection of the Ogallala aquifer. Dr. Porter mentioned that Kansas has better extension materials than Texas A&M does. The activities of the joint project include field days and revision of extension publications, among other extension activities. The next state report was given by Dr. Schwankl . He provided as a hand out to the participants a publication titled California microirrigation pocket guide. He also provided some copies of a maintenance handbook, and mentioned the website from which the publication can be downloaded is http://anreatalog.ucdavis.edu (search for publication number 21637). The idea of writing joint publications among states brings up the idea of creating a wiki site for the w-1128 project. Dr. Rein said that a wiki site such as Wikipedia is not considered a scientific site. The advantage of a wiki site is that a group of people can work on a document on the internet without the difficulty of sending documents back and forth. Dr. Parson from UFL presented his research dealing with the testing the Australian sensor SENTELPROBE and ECHO probe EC-5 soil sensor for scheduling irrigation on strawberries. Dr. Ali Fares presented software developed by the water management district of Hawaii to confer water use permits by the state of Hawaii (regulatory software). He explained all the inputs and outputs of the model. Dr. Craig Stanley mentioned that he is working mostly in water management for urban landscapes (looking at run off in turf and landscapes). He is working in alternative sewage treatments such as a treatment to take out the N and return it to the septic tank. Then Dr. Neibling from Idaho informed about his research comparing drip irrigation to sprinkler irrigation on canola. Drip treatment performed better than sprinkler irrigation. He also mentioned that turf grown over buried irrigation systems in a 4 year study showed no intrusion of roots into the drip tape. He mentioned that he is working on a project testing computer based scheduling programs under Idaho conditions. Dr. Shukla says that a more accurate method for measuring soil moisture is gravimetric than the neutron probe. The discussion was stopped for lunch. The discussion resumed at 1:30 pm with Dr. Lamm commenting about a short meeting with coordinators before lunch. They agreed that if researchers send a title and objectives that do not fit the current proposed objectives, then it will be returned to the researcher to find a research topic that fits, unless something comes up that may be of multistate interest, then a new objective could be created. Dr. Mick ONeill talked about his ongoing research on irrigation scheduling in hybrid poplar trees. He tested 70, 80, 120, and 130% ETc on four poplar clones. The next state report was given by Dr. Shukla from NM, who talked about field and laboratory calibration with CS640. He calibrated the sensor to fit the field data. Dr. Shock talked about comparison of irrigation of onion by microsprinkler and drip irrigation. Water applied is way over ETc. Dana Porter talked about her extension work in Texas with other colleagues. The meeting adjourned about 5:00 pm.

Objective 1. To identify and assess the significance of barriers to adoption of microirrigation. No more to accomplish in this objective. Objective 2. To reduce technical barriers associated with microirrigation system design, performance, and maintenance. The relative response of cotton to subsurface drip irrigation (SDI), low-energy precision application (LEPA), and spray irrigation varied with irrigation rate (25%, 50%, 75%, and 100% of full crop evapotranspiration) and inter-annual climatic variability (2003, 2004, and 2006, and 2007 seasons). For deficit irrigation (2-5 and 50% irrigation rates), SDI generally resulted in greater cotton seed yield, lint yield, water use efficiency, and gross returns; however, differences in response parameters were not always significant. Loan value (as reflected by fiber quality) was greatest for SDI for most irrigation rates in 2003 and 2004, but greatest for LEPA for all irrigation rates in 2006. SDI resulted in greater near-surface soil temperatures by 95 days after planting (2006 only), which is a critical consideration for cotton production in thermally-limited climates such as the Northern Texas High Plains and Southwestern Kansas. In 2007, only seasonal water use and seed yield were available due to a significant gin backlog. Unlike previous years, SDI used significantly less water at 25% and 50% irrigation rates; however, seed yield was not significantly different among methods at 25%. At 50%, LEPA resulted in the largest seed yield, whereas SDI resulted in the largest seed yield at 75 and 100%. Corn emergence and final grain yield were evaluated for different subsurface drip irrigation (SDI) bed geometries and lateral depths. Bed geometries consisted of laterals installed in every bed, laterals installed in alternate furrows, and laterals installed in wide beds with twin planted rows (same lateral spacing as alternate furrows). For each bed design, lateral burial depth was 15, 23, and 30 cm, and irrigation rates were 0%, 33%, 66%, and 100% of full crop evapotranspiration (ETc). No significant differences in crop emergence were observed for bed design within a given irrigation rate. Most grain yield variability was related to irrigation rate; however, grain yield was significantly greater with increasing lateral depth (but not bed design) for the 33% irrigation rate. This was likely due to greater evaporation of soil water for shallower lateral depths, which limited final grain yield at the very low (33%) irrigation rate. This experiment will be repeated for corn in the 2008 season and cotton thereafter. Corn yield has not been negatively affected by various emitter spacing of 0.3, 0.6, 0.9 or 0.4 m on a deep well-drained soil in a semi-arid, summer pattern rainfall climate in Kansas. There is some soil water redistribution occurring along the subsurface dripline that helps to mitigate application differences caused by the different emitter spacing. Sunflower, grain sorghum, and soybean yield have not been significantly affected by subsurface dripline depth (0.2, 0.3, 0.4, 0.5 and 0.6 m) in studies where crop germination and establishment were not a factor. Another accomplishments for KS was the development of a software to compare the economics of conversion to center pivot sprinkler irrigation or subsurface drip irrigation from furrow irrigation for corn production was updated and released to the public, February, 2008 http://www.oznet.ksu.edu/sdi/Software/CP_SDI08.xls. Also a software to determine optimum planned corn area and plant population for SDI was updated and released to the public, February, 2008 http://www.oznet.ksu.edu/sdi/Software/COpt_SDI08.xls Potato is conventionally planted in hills. Drip-irrigated potato planted in hills was compared with drip-irrigated potato planted in flat beds with one drip tape per row of plants at 6 cm depth. Potato grown in beds was more productive and tubers had more uniform shape. Additional work focused on drip tape placement and potato row configurations on flat beds. Deep placement of drip tape has been shown to reduce tuber yield and quality compared to shallow placement. Drip tape placement at 6 cm depth was varied horizontally on flat beds 1.8 m wide: two tapes were placed directly in line with each of two plant rows, two tapes were placed 18 cm along side of each two row towards the middle of the bed, or two tapes were placed between each of two double rows of potato. Plots of potato were irrigated independently when the soil water potential between the plants reached -30 kPa. The horizontal tape placement options did not affect tuber yield, grade, or marketable quality. In commercial fields, drip tape placed directly in the crop row was subject to pinching by developing tubers. Pinching of the tape resulted in lost yield in the rows beyond where the tape was pinched. Under drip, the water required to maintain soil water potential was less than 70 % of estimated potato crop evapotranspiration. Objective 3. To reduce existing water and nutrient management barriers associated with microirrigation. Corn was grown with subsurface drip irrigation to determine the effect of pre-anthesis water stress. The results from KS indicate that corn has great ability to tolerate pre-anthesis water stress provided the water deficits can be quickly relieved through irrigation near anthesis. Advanced irrigation scheduling technology using Temperature-Time Threshold or BIOTIC method of irrigation scheduling can be used to effectively irrigate corn in the U.S. Central Great Plains. A TTT of 2.5 hours appeared to correspond reasonably well to a 100% ETc replacement treatment for both grain yield and irrigation amount. Similarly, a 5.5 hour TTT treatment corresponded reasonably well to a 65% ETc replacement treatment. In CA, the fifth and last year of an almond plant-based RDI study showed that almond yields could be fully maintained despite reductions in applied water. These reductions were about 10% below the most conservative estimates of crop ET, and were accomplished on shallow soils with poor water holding capacity. The pooling of data from multiple states, crops and years also showed that surprisingly low amounts of applied water (40 - 50% of tall or short reference ET, respectively) corresponded to levels that were adequate to achieve full crop yield. A group of W-1128 members from CA, NM and TX were successful in obtaining a $4.7M SCRI grant for "Advanced sensing and management technologies to optimize resource management in specialty crops: case studies of water and nitrogen management in deciduous crops under normal and resource-limited conditions. Research conducted in PR during the last two years indicate that avocados trees responded better to a high soil water depletion level (HSWD=40-45 kPa) than a low soil water depletion level (LSWD=10-15 kPa) or rainfed conditions. Trees submitted to HSWD produced the highest canopy volume, fruit number and weight per tree. Microirrigation is needed to achieve acceptable yield if compared with trees growing on rainfed conditions even though is a fairly wet region. Several years of research on an Oxysol in northern Puerto Rico indicated citrus trees (CV Rhode Red Valencia) was not affected by microirrigation. Another factor is limiting orange productivity and growth resulting in low yield. Therefore, another citrus orchard (CV. Rhode Red Valencia grafted on Swingle and Sunki-Benecke rootstock) was established in 2007 in a major citrus production area in which tensiometers are used to schedule microirrigation. The hybrid poplar, OP-367 continued to demonstrate superior yields in both high density (1,740 trees/ac) and low density (435 trees/ac). After 5 growing seasons, this clone produced 93 tons/ac (19 tons/ac/yr) in the high density trial planted in 2003 and after 6 seasons it produced 87 tons/acre (15 tons/ac/yr) in the low density trial planted in 2002. It was also the highest yielding clone (54 tons/ac, 18 tons/ac/yr) after 3 growing seasons in a DOE-supported trial planted at a density of 1,210 trees/ac. A 6-ac poplar trial with 4 outstanding P. deltoides x P. nigra clones, including OP-367, from the DOE trial and 4 water application treatments was planted during April 2007. Preliminary yield data taken during October 2008 while leaves were still on the trees indicate good growth for these D x N clones. Although OP-367 was not the largest entry, it still yielded more than in previously planted trials. The 1.5-acre drip-irrigated vineyard planted in 2007 was rearranged during 2008. Along with the variety trial that includes 14 table and 20 wine grape varieties, and a rootstock trial was installed in 2008 with 2 varieties grafted onto 9 different rootstock. Interest continues with the low-tech, low-cost drip-irrigated vegetable garden and the xeric landscape demonstration for small-scale gardeners and home owners. About 3,540 pounds of marketable produce were harvested from the drip-irrigated (0.14 acre) garden in 2007. This total included 1,559 lbs (49 lugs or 29 bushels) of tomatoes, 391 pounds (55 dozen ears) of sweet corn, and 1,591 pounds (40 sacks) of chili peppers. As in previous years, most plants in the xeric garden survived at all irrigation levels (including rain-fed only) and most exhibited acceptable quality at either the low (20% ETtall) or medium (40% ETtall) irrigation treatment. Based on these results, it appears a crop coefficient of 0.3 (30% of ETrs) may be sufficient for planning and estimating the total water requirements of a large, mixed-species xeric landscape in the Four Corners region. A multi-season field experiment was conducted to monitor the movement of water and nutrient contents under a drip irrigation system. Sweet corn was cultivated at Waimanalo research station of the University of Hawaii at Manoa. Soil organic treatments were three rates of chicken manure and compost replicated three times. The field was under regular tillage during first and third cropping seasons whereas No-Till was adopted during the second cropping season. Soil solutions within and below the crop root zone were collected using suction cup lysimeters. Water samples were collected from the lysimeters weekly or bi-weekly. The soil solution samples were analyzed for NO3, pH and electric conductivity. These soil water samples were also analyzed for the major macro and micronutrients. Multisensor Capacitance Probes (MCPs) were installed at each treatment to monitor soil water content within and below the crop root zone. Each MCP contains 4 moisture sensors at 10, 20, 30, and 50 cm depths who were monitored via a data logger near real-time. The first three sensors (i.e., at 10 through 30 cm depths) monitored water contents within the root zone and the fourth at 50 cm depth monitored water content below the root zone. The sensors were logged at 15 minutes intervals. Soil moisture data was downloaded from the data loggers on weekly and/or bi-weekly basis. This data was analyzed using the water balance approach to determine plant water use and excess water losses below the rootzone. At the end of each cropping season, plant root and shoot samples were collected and analyzed for nutrient concentration. Undisturbed soil cores were collected from each treatment at 10, 20, 30, and 50 cm depths. Soil physical properties including bulk density (BD) and soil total porosity (TP) were determined following standard procedures. The results showed that BD decreased and TP increased with increase in manure and compost application rates. Decreased BD and increased TP result in increased soil water retention. Tension and double ring infiltrometers were used to determine the steady state infiltration rates in each treatment plot. The steady state infiltration rates were used to determine soil hydrological properties, i.e., saturated hydraulic conductivity (Ks) of the soil. The results show that Ks increased with increase in manure application rates. Similar trends were found in compost treatments. Increased Ks makes soil water and hence the dissolved nutrients available for plant uptake. Soil disturbed samples that were collected from the top 15 cm soil layer were processed for soil chemical properties including soil organic matter (SOM), soil organic carbon (SOC), pH, electrical conductivity (EC), and nitrate concentrations. In addition to improving soil aggregation, the organic manure application to this tropical soil increases SOC pools that contribute to the atmospheric carbon dioxide upon tillage and other agricultural practices. An Irrigation Water Requirement Estimation Decision Support System (IWREDSS)  a GIS-based version of IManSys was developed for Hawaii Commission on Water Resources Management to use in their water allocation for different water users across the state. IWREDSS produces spatially distributed irrigation requirements and different water budget components. IWREDSS uses a water balance approach to calculate the major field water balance components, e.g., effective rainfall, canopy interception, surface runoff, and water redistribution and extraction by evapotranspiration on a daily basis. IWRDESS was calibrated and validated using published data for Hawaii. Hybrid poplar (cultivar OP-367) had been planted for sawlog production in April. Five irrigation treatments were established in 2000 and were continued through 2008. Irrigation treatments consisted of three treatments using microsprinklers and two using drip tape. The three microsprinkler treatments consisted of one adequately irrigated check (irrigations at 25 kPa soil water tension and 51 mm of water per irrigation) and two lower irrigation treatments (irrigations initiated when the check treatment is irrigated, but with of 34 mm and 17 mm applied per irrigation). The two drip-irrigated treatments were irrigated separately at 25 kPa soil water tension and 51 mm and 25 mm applied per irrigation. Soil water tension was measured at 20-mm depth. The most productive treatments received considerably more water than estimated crop evapotranspiration. Stem volume in the fall of 2007 and stem volume growth from 2000 through 2007 were highest with drip irrigation applying 25 mm of water per irrigation at a soil water tension of 25 kPa. The microsprinkler-irrigated poplar with 34 mm and 17 mm per application had proportionally lower sawlog production that the treatment receiving 51 mm per application. Research and Extension work at Idaho evaluating the performance of Decagon soil water sensors and data loggers was expanded this year. Sensors and data loggers were installed at 4 depths in soils with textures ranging from sandy to heavy silt loam. Sensor readings were periodically compared to soil water content determined by field sampling and gravimetric water content analysis. A field study evaluating 4 levels of irrigation water application under drip and sprinkler irrigation on oilseed production of winter canola was conducted at the Kimberly R&E Center in 2008. Irrigation was added to supply 50, 75, 100 and 125% of estimated ET. Onion plants infected with iris yellow spot virus (IYSV) can progressively lose leaf area, resulting in reduced yield and reduced bulb size. The virus is transmitted by onion thrips (Thrips tabaci). The incidence of IYSV can be increased by inadequate control of onion thrips, which have become increasingly resistant to pyrethroid and organophosphate insecticides. A certain degree of varietal tolerance to thrips and IYSV has been determined. However, management factors such as irrigation, fertilization, and straw mulching that reduce plant stress might reduce the intensity of thrips and IYSV infestations. Onion expression of IYSV, yield, and 50-mm depth soil temperature responses are being determined to irrigation criteria, irrigation system (drip, sprinkler, or furrow), nitrogen fertilizer rate, and straw mulching. Native forb 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. A major limitation to economically viable commercial production of native forb seed is stable and consistent seed productivity over years. 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. Native forbs are not competitive with crop weeds. Both sprinkler and furrow irrigation could promote seed production, but risk encouraging weeds. Furthermore, sprinkler and furrow irrigation can lead to the loss of plant stand and seed production due to fungal pathogens. By burying drip tapes at 30 mm depth, and avoiding wetting of the soil surface, we hope to assure flowering and seed set without encouraging weeds or opportunistic diseases. Current trials are testing the effects of three irrigation intensities (coordinated with the flower formation, flowering, and seed set of each species) on the seed yield of 13 native forb species. The total irrigation water requirements for these arid land species has been shown to be low, in the range of 100 to 200 mm/year, and varied by species.

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Response of Selected Soil Physical and Hydrological Properties to Manure Amendment Rates, Level and Types. Soil Science 173: 522533. Harmsen, E. W., 2007. Small-Scale Rainfall Variability in Western Puerto Rico and its Implications on Agricultural Water Management. Annual meeting SOPCA 2007, Centro de Convenciones de Cataño, Cataño, Puerto Rico, November 15, 2007. Harmsen, E. W., 2007. The Potential Impact of Climate Change on Agricultural Water Resources in Puerto Rico. Segunda Jornada Científica del Colegio de Ciencias Agrícolas, March 16th, 2007. University of Puerto Rico  Mayagüez Campus. Lamm, F. R. and A. A. Abou Kheira. Effects of early-season water stresses on corn production. Proc. 29th Annual Intl. Irrigation Assoc. Tech. Conf., Anaheim, California, Nov. 2-4, 2008. Available from Irrigation Association, Falls Church, VA. Paper No IA09-1052. 10 pp. Lamm, F. R., and R. M. Aiken. 2008. Comparison of Temperature-Time Threshold-and ET-based Irrigation Scheduling for Corn Production. ASABE paper no. 084202. Available from ASABE, St. Joseph, MI. 12 pp. Lamm, F. R., D. M. OBrien, D. H. Rogers, and T. J. Dumler. 2008. Using the K-State center pivot sprinkler and SDI economic comparison spreadsheet  2008. In: Proc. Central Plains Irrigation Conference, Greeley, CO., Feb. 19-20, 2008. Available from CPIA, 760 N.Thompson, Colby, KS. pp. 61-70. Lombard, K.A., M.K. ONeill, R.F. Heyduck, B.M. Onken, R.G. Pablo, D. Smeal, R. N. Arnold, A. Ulery, and J. Mexal. 2008. Evaluation of field grown hybrid poplar OP-367 after amending with biosolids. In: ONeill, M.K. (ed). Soil and water conservation research in the arid Four Corners region. Symposium, Soil and Water Conservation Society Annual Meeting. July 27-31. Tucson, AZ. Neibling, W.H. and J. Robbins. 2008. Understanding your water supply options. University of Idaho CIS. In press. Neibling, W.H. and J. Robbins. 2008. 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Pereira, A.B., C.C. Shock, B.G. Feibert, and N.A. Villa Nova. 2008. Performance of "Irrigas" for onion irrigation scheduling compared to three soil water sensors. Engenharia Rural. 18:109-114. Qureshi, Z and W. H. Neibling. 2008. Response of Two-row Malting Spring Barley to Water Cutoff under Sprinkler Irrigation. Agric. Wager Manage. doi 0.1016/j.agwat.2008.07.012 Ramírez, V. H., E. W. Harmsen and T. Porch, 2007. Crop Water Stress Index and Yield Components for New Common Bean (Phaseolus vulgaris L.) Genotypes in Greenhouse and Field Environments. Poster presentation. Annual meeting SOPCA 2007. Centro de Convenciones de Cataño, Cataño, Puerto Rico, November 15, 2007. Román-Paoli, E., F. Román, J. Zamora. 2008. Evaluation of microirrigation levels on growth and productivity of avocado trees. J. Agric. Univ. PR. (Accepted). Román-Paoli, E., J. Beaver. 2008. Performance of a Quality Protein Maize variety in a Vertisol. 44th Annual Meeting, Caribbean Food Crop Society. 13-18 July. Miami, Florida Shock, C.C. 2008. The Canon of Potato Science: 31. Irrigation. Potato Research 50:331-333. Shock, C.C., S. Irmak, B. Sanden, L.A. Lima, K. Taylor. 2008. Grower Adoption of granular matrix sensors. ASA/CSSA/SSSA annual meeting, October 5-9, 2008, Houston, TX. Shock, C.C., E.B.G. Feibert, L.D. Saunders, and J. Ishida. 2008. Identification of post-emergence herbicides for use in native forb seed production. Great Basin Native Plant Selection & Increase Project Annual Meeting, Salt Lake, UT, February 12, 2008. Shock, C.C., E.B.G. Feibert, L.D. Saunders, and J. Ishida. 2008. Native forb seed production in response to SDI in 2007. Great Basin Native Plant Selection & Increase Project Annual Meeting, Salt Lake, UT. February 12, 2008. Shock, C.C. 2008. Perspectives on onion irrigation scheduling and drip irrigation. Stress on onion and its impact on ISYV development. 48th annual meeting of the Malheur County and Eastern Idaho Onion Growers Annual Meeting, Four Rivers Cultural Center, Ontario, February 5, 2008. Shock, C.C. 2008. Perspectives on onion irrigation scheduling and drip irrigation. Drip Irrigation Conference, Clearwater Supply. February 6, 2008. Shock, C.C. 2008. Irrigation management for potato. AS Wilcox Potato Conference, Pukekohe, New Zealand, August 28, 2008. Shock, C.C. 2008. Research initiatives. AS Wilcox Potato Conference, Pukekohe, New Zealand, August 28, 2008. Shock, C.C. E.B.G. Feibert, L.D. Saunders., L. Jensen, and K. Mohan. 2008. Management of onion cultural practices as a means to control the expression of iris yellow spot virus. Oregon State University Agricultural Experiment Station, Special Report 1087: 34-51. Shock, C.C. E.B.G. Feibert, and L.D. Saunders. 2008. Microirrigation alternatives for hybrid poplar production, 2007 Trial. Oregon State University Agricultural Experiment Station, Oregon State University Agricultural Experiment Station, Special Report 1087: 84-95. Shock, C.C. and E.B.G. Feibert. 2008. Performance of hybrid poplar clones on an alkaline soil through 2007. Oregon State University Agricultural Experiment Station, Special Report 1087: 100-104. Shock, C.C. E.B.G. Feibert, L.D. Saunders, and N. Shaw. 2008. Subsurface drip irrigation for native wildflower seed production. Oregon State University Agricultural Experiment Station, Special Report 1087: 183-196. Shock, C.C., J. Ishida, and E.B. Feibert. 2008. Native wildflowers grown for seed production show tolerance to conventional postemergence herbicides. Oregon State University Agricultural Experiment Station, Special Report 1087: 197-203. Smeal, D., M.K. ONeill, R.N. Arnold, K.A. Lombard. 2008. Crop coefficients for climate-based irrigation scheduling in semi-arid urban landscapes. In: ONeill, M.K. (ed). Soil and water conservation research in the arid Four Corners region. Symposium, Soil and Water Conservation Society Annual Meeting. July 27-31. Tucson, AZ. Smeal, D., M.K. ONeill, R.N. Arnold, and K.A. Lombard. 2008. Crop coefficients for scheduling irrigations on drought tolerant landscapes. WaterSmart Innovations Conference and Expo. October 8-10, 2008. Las Vegas, NV. Smeal, D., M.M. West, Z.F. Williams, M.K. ONeill, K.A. Lombard and R.N. Arnold. 2008. Efficient irrigation of small plots using a simple, inexpensive micro-irrigation system. Proceedings: ICASALS 2006 Conference: Water in Arid and Semiarid Lands: Innovative Approaches and Informed Decision-Making. Nov. 15-17, 2006. Lubbock, TX. In Press. Smeal, D., Z.F. Williams, M.M. West, M.K. ONeill, and R.N. Arnold. 2008. Drought-tolerant plants for urban landscapes in northern New Mexico. Symposium on Efficient Water Use in the Urban Environment. February 23-24, 2006. Las Cruces, NM. In Press. Smeal, D., M.K. ONeill, R.N. Arnold, and K.A. Lombard. 2008. Crop coefficients for scheduling irrigations on drought tolerant landscapes. WaterSmart Innovations Conference and Expo. October 8-10, 2008. Las Vegas, NV.