Duration: 10/01/2010 to 09/30/2011

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Irrigated agriculture continues to increase rapidly across the Southeast United States. Competition for limited water resources is one of the most critical issues being faced by irrigated agriculture in the United States and this is especially true for the Southeast. It has been the common belief that there is plenty of available water to meet the water needs but that has been brought into question as issues arise across the region. The partial examples that follow illustrate the issues that Southeastern States are facing.

Governors of Alabama, Florida and Georgia scheduled to announce whether they have reached a negotiated settlement to their 17-year water war. They missed this deadline.

Trans-boundary water rights issues are also being debated between South Carolina and its North Carolina and Georgia neighbors, while news reads North Carolina's attorney general balks at secret water talks with South Carolina.

Corps of Engineers South Atlantic Region Commander Brig. Gen. Joseph Schroedel will convene a 16-state workshop to discuss creation of a water council to solve the southeast U.S. water sharing issues.

Georgia governor, lieutenant governor and House speaker appoint 300 farmers, government officials, businessmen and others to 10 regional councils to allocate water from the state's rivers, lakes and aquifers.

Southeastern United States experience drought conditions on a regular basis. Irrigation is becoming much more common as a means of risk reduction as well as a means of stabilizing or improving income. Surface water as well as ground water is utilized as a source of irrigation water. See http://www.drought.unl.edu/dm/monitor.html for map.

Recent drought in many areas has heightened the need to balance water demand with the available supply while ensuring the minimum in-stream flow requirements to meet human and environmental needs. The 13 Southern Region states are challenged to maintain an available, high-quality water supply in a region encompassing 19 million irrigated acres.

Ground-water depletion has been a concern in the Southwest and High Plains for many years, but increased demands on our ground-water resources have overstressed aquifers in many areas of the Nation, not just in arid regions. In addition, ground-water depletion occurs at scales ranging from a single well to aquifer systems underlying several states. The extents of the resulting effects depend on several factors including pumpage and natural discharge rates, physical properties of the aquifer, and natural and human-induced recharge rates

Conservation officials have declared 11 counties in Arkansas as critical groundwater decline areas and 21 more counties are under evaluation. In areas where subsidence has been attributed to ground-water pumpage. See http://water.usgs.gov/ogw/pubs/fs00165/SubsidenceFS.v7.PDF for map.

2009, South Carolina Senate introduced a bill (S. 452) to amend their 1976 Code relating to surface water withdrawal and reporting. This is expected to alter rights and exceptions and may impact irrigation water withdrawals during periods of drought when minimal stream flow requirements are not met.

Arkansas Ground Water Protection and Management Report for 2009
Irrigated acres are declining in the arid western states while continuing to increase in the Southeast. The blue areas on the left represent increasing irrigation while the red areas show declining irrigated acres over the period of 2002 to 2007. See
http://www.agcensus.usda.gov/Publications/2007/Online_Highlights/
Ag_Atlas_Maps/Farms/Land_in_Farms_and_Land_Use/
07-M081-RGBDot2-largetext.pdf for maps

Much of what we know about irrigation was developed in areas where rainfall is minimal. The applicability of such results to the humid and sub-humid region is still in question. We continue to apply technology and develop solutions based on technology and concepts that may not be applicable to the area and in most cases do not include analysis of all available options. The illustration to the right shows the availability of freshwater. Blue and green areas have developed more than 100% of the available water while the yellow area (eastern US) is utilizing less than 75% of our freshwater runoff. We have a water management problem, not a water shortage, but the current technology and economics cannot provide adequate solutions that strongly consider the development, management, and distribution of our abundant surface water resources.

Expansion of irrigation in the Southeast in the last 25 years has largely occurred without strong research and extension efforts in the affected states. This view is supported by the fact that roughly three quarters of the ARS irrigation research scientists are located in the western states. Currently, very few ARS water management research scientists are located in the region.

A.The need as indicated by stakeholders.

The need for research and extension is critical to develop adequate water management plans that maintain productive capacity. First, there is limited knowledge of the variations in crop water use and irrigation needs among the major crops and dominant soils in humid climatic zones. Secondly, the effectiveness and suitability of various water management strategies and scheduling tools and techniques in different crops and soils needs to be determined and improved. Studies on comparison of traditional and modern irrigation systems and their potential water and energy savings are equally scarce. The third issue is more philosophical on the surface, but has profound on-farm implications. It suggests a serious lag in awareness and adoption of the best irrigation water and system management practices in humid areas either due to historical practices, labor availability, or new irrigation in areas that were not irrigated in the past. Many producers in humid areas were raised in a rain fed culture and may not fully understand the basics of irrigation water and system management. This limits their ability to take full advantage of irrigation and its higher input requirements for achieving more stable profits and high water and energy use efficiency. Additionally, there is a need for a more critical assessment of the economics of irrigation alternatives in humid regions because rainfall can help in meeting most crop water needs in many years. Thus, the costs of installation and operation of irrigation systems over the long term must equal the benefits. In addition, small issues that have larger economic, reliability, and trust impacts (like loss of equipment, wiring, batteries; maintenance schedules under intermittent use; etc.) must also be fully addressed because farmers have neither the patience nor flexibility to sustain losses under current agricultural economic conditions. Most past efforts have addressed key knowledge gaps identified in the first two issues mentioned above, yet socio-economic and other barriers to adoption are less emphasized. These latter needs must be tackled through state-wide outreach programs that promote water-wise practices and cost-share incentives as well as help strengthening the managerial capabilities of the irrigators and the level of extension expertise in managing modern irrigation systems for high water and energy productivity. A study completed in 2006 revealed the following general technology areas and research questions needing attention across the southeast. All of these questions or technology areas have cross topic concerns.

Irrigation Efficiency

Given that there is extensive recycling of water from drainage canals and bayous onto farms, at what field-level efficiency should the farmer be operating?

Will improvements in field- or farm-level efficiency lead to large improvements in project level efficiency or is project-level efficiency already >90%?

To what extent will improvements in field- or farm-level efficiency lead to

o Improved project-level efficiencies?

o Improved economics and cost of energy reductions?

o Lower concentrations of sediment, nutrients, and pesticides/herbicides in streams?

o Improved farm economics due to more efficient use of applied chemicals and reduced irrigation pumping cost?

How much of current irrigation water demand could be met by on-farm conservation including the use of tail water pits, storage reservoirs, and replacement of earthen ditches with piping?

Irrigation application efficiencies  what are they and what can they be?

What inexpensive equipment can be developed/adapted for automation and remote control of irrigation pumps?

What are the effects of irrigation storage reservoirs and tail water systems on overall farm level irrigation efficiency and water quality?

Irrigation Methods/Management

What changes can be made to make rice irrigation more efficient? Is it likely that rice irrigation methods will change away from continuous flood to more efficient methods?

What is the role of multiple-outlet paddy flooding systems?

Will other practices such as center pivot sprinklers, level basins, poly-pipe for in-field distribution to furrows or paddies, etc. increase efficiencies and economics?

Irrigation scheduling. What is the best way to schedule irrigation when water logging is as likely and harmful as water deficits? The last date to irrigate must be known to maximize soil water storage so as to reduce runoff and nutrient loss in case of rainfall after irrigation. Crop water use values must be determined for varieties and climate of the region.

What are the management guidelines for reservoir - tail water pit systems that will minimize pumping costs and maximize water capture?

What are the threshold soil water depletion levels (i.e., irrigation set points) for stress-free growth as a function of stage of growth? What is the temporal variation in effective root zone under row crops and under drip irrigated vegetables?

How does the new automated, sensor-based irrigation and fertigation scheduling compare with the current growers' practices? What is the profitability and adoption rate of automated, sensor-based irrigation and fertigation for vegetable production in the southeastern U.S.?

User friendly GIS database management for irrigation system operation would be useful.

Commercial systems exist for center pivot systems. Can a similar system be developed for surface irrigation systems that include reservoirs, tail water pits and re-lift pumps?

Social Issues

How will competing interests of agricultural, industrial, and municipal users be resolved?

What are the competing entities and their water requirements now and in the future?

What is the federal government's interest in water resource development, and what should the goals be?

Socio-economic studies are needed. A study has been done for Grand Prairie but not elsewhere.

Arkansas generates approximately 80 million acre-feet of runoff yearly. There is a need to develop 10% of this. How should it be done?

As irrigated acreage decreases in the semi-arid Great Plains and arid west, what pressures will occur to change irrigation (crops, efficiencies, methods) in the LMRV and southeast United States?

Soil - Irrigation Interactions

What are pertinent soil properties that will influence possibilities, opportunities and outcomes for irrigated agriculture?

Some soils in the Lower Mississippi River Valley (LMRV) appear to be hydrophobic. How can they be ameliorated?

Hydraulic conductivities are low in typical soils of the LMRV, which are extremely low in organic matter and have massive structure. Which irrigation methods are favored in these soils?

What are organic matter effects on soil physical characteristics?

Fragipans and tillage pans are common in LMRV soils. How do they affect irrigation efficiencies and yields and what remediative measures are appropriate?

Irrigation Project Design and Management

How is the hydrology and water balance of irrigated areas affected by design alternatives such as on-farm storage reservoirs, tail water pits, and re-lift pumps?

What is the life of storage reservoirs being built today?

What can be done to control embankment erosion, which is a serious problem in the uncohesive silt loam soils common in the region? Are there chemical soil treatments such as poly acrylamide (PAM) that can control erosion? Are there more effective and cost-effective seeding options?

What is the life of tail water pits being built today? What is the rate of sedimentation in tail water pits?

Production Practices/Agronomics

What are the effects of row spacing and plant density on irrigation efficiency and the economics of production?

What are the effects of PAM on soil erosion and infiltration in irrigated systems?

Crop water use measurement and prediction. To what extent can irrigation scheduling improve water and nutrient management in a system where water is captured in tail water pits and recycled?

No-till rice production to improve soil organic matter and thus structure and related properties.

How do tillage practices affect crop water use?

How do hydroponics and sprinklers fit into the water re-use practiced on SE Arkansas farms that produce fish, rice, and cotton simultaneously?

B. The importance and extent of the problem.

There is strong debate in Arkansas on the wisdom of diverting surface water from rivers for irrigation. This same debate is occurring in Florida, Alabama, and Georgia as a result of the water wars in that region, and the implementation of new approaches to manage water within geographic and political boundaries. This debate will not be limited to these locations alone, and will escalate as agricultural water use competes with other consumptive needs (municipal, industrial, etc.), societal needs and environmental considerations. The debate centers around effects of diversion or use on important sport fisheries, on riparian wildlife and habitat, on maintenance of adequate stream flows during the summer months, and on water quality. These conflicting needs generate a demand that water diverted for irrigation is used as efficiently as possible, and that environmental impacts are minimized for well designed and operated irrigation schemes. Irrigation water use efficiency at field, farm, and project levels, irrigation project design alternatives to improve overall water use efficiency, and enhanced knowledge transfer to producers are research topics that are of critical importance to the successful management of our water resources. It is also critically important as water allocations are considered from existing streams, lakes, and reservoirs.


C. The technical feasibility of the research

Each participant in this research program has experience with irrigation research and/or is associated with a funded (or anticipated) irrigation research park or facility. Project plans and procedures indicated below outline the scientific basis for high quality research that is publishable in refereed journals as a basis for clientele decisions.

The organizational support for irrigation research is quite extensive throughout the humid and sub-humid region indicating this type research is a priority. The potential to meet irrigation research needs while minimizing duplication across similar crop, climatic, and physiographic locations encourages more efficient utilization of funding for irrigation research. For example, irrigation research on scheduling of peanut irrigation occurs in Georgia (more than one location), Florida, Alabama, and Texas. Researchers are investigating computer-based irrigation scheduling to sensor feed-back controls to on-farm irrigation scheduling devices. Each of these approaches has merit to a different population of farmers and other end users involved in irrigation. However, collaborations across locations are expected to yield more comprehensive results.


D. The advantages of doing the work as a multi-state effort.

Local efforts are underway to address certain issues but are generally not set up as research trials. S1018 encourages the exchange of information and serves as a mechanism to facilitate information and technology exchange. Information such as projects, project objectives, studies, available reports, technology utilized, and general results are being exchanged. Before the S1018 project, there was no formalized process to exchange basic information among agencies and with organizations outside of the multi-state project approach. The first five-year humid area irrigation project, S1018, started the process, but there is still much that needs to be done. The multi-state project following S1018 will continue to serve as the forum to exchange information on projects and studies that address surface water, runoff, water quality, and similar water related issues tied to agricultural irrigation across humid areas.


E. Benefits or impacts of the research or information exchange including impact on science.

Using a multi-state approach to meet these objectives will allow plot, field and national-scale methodologies to be implemented with a reduced potential for overlap between locations. In addition, technologies can be explored for compatibility across different physiographic, soil, and climatic conditions to ensure application potential of resulting technologies. For example, cotton is irrigated in several locations throughout the humid region. Irrigation scheduling, profitability characteristics as associated with irrigation water management, and cultivar responses to irrigation management alternatives would benefit from a comprehensive regional effort.

Landscape and turf irrigation are also practiced across the entire humid and sub-humid region. The potential to save water via conservation based upon improved sensor technology and better scheduling could reduce the potential for implementation of severe water restrictions. Within the past ten years, severe restrictions to complete outside watering bans have been utilized in many communities in humid and sub-humid areas to help conserve water resources. Individual users and the nursery industry (one of the fastest growing agricultural enterprises in the United States) would greatly benefit from proactive water management approaches that could ward off or mitigate watering restrictions.

Irrigation water management strategies have primarily been developed in areas where rainfall is minimal. The application of water management strategies developed for arid conditions to the humid and sub-humid region may have significant limitations, especially with regard to irrigation scheduling. Irrigation research will require a more critical assessment of economic potential and risk assessment based upon rainfall probabilities in humid and sub-humid areas. The long-term benefits must exceed the costs to install and operate irrigation systems before the technology will be adopted on a large scale in agriculture.


F. Identify the stakeholders, customers, and or consumers of the project results.

The most important benefits from this research will be the community of people living and working in humid areas. Irrigated farms throughout the humid and sub-humid region, homeowners and businesses with irrigation, state and national agencies that are responsible for reducing water consumption and improving water management, and all those who benefit from another water user improving their water use efficiency will benefit from this research and technology transfer effort. Irrigation and water applications are a component in a comprehensive analysis of costs and returns on those investments. In Florida, for example, the stakeholder group includes at least 15 million water users and consumers. An in-ground irrigation system is standard in new home construction in the state, and Florida has a significant proportion of all new home construction in the US. In North Carolina, there are multiple pending bills that address water use across multiple sectors and that seek to allocate water based upon consumptive use. Increasingly, states in humid areas have to implement water management strategies to address increasingly limited water resources and competition between urban and agricultural users.

Specific stakeholders include but are not limited to: Members of South Carolina Cotton Board and South Carolina Soybean Board, Cotton Incorporated, SC Department of Environmental and Health Control (DHEQ), North Carolina Division of Water Resources, the vegetable industry (as represented in numerous meetings, i.e., South Carolina / North Carolina Vegetable Expo, Southeastern Vegetable Expo, Eastern Shore Ag. Expo, SC Specialty Crops annual meeting), Alabama Cotton Commission, AR Rice Research Promotion Board, Yazoo Water Management District, National Water Management Center.

Related, Current and Previous Work

Improvements in irrigation application technologies enhance crop production and reduce water use. Improved field moisture and yield monitoring techniques determined the response of cotton yield versus various sprinkler irrigation schedules. Remote sensing data were overlaid with cover crop management as a function of individual irrigations. Dry year results indicated a classic response to irrigation depth, as a percent of pan evaporation x canopy cover, with a point of diminishing yield returns highlighted as a peak in cotton seed yield. The drought years of 2006 and 2007 were ideal years to show such a relationship. Yields for 2008 and 2009 were more consistent across treatments. Cotton yield was improved 3-fold through improvements in sprinkler irrigation and fertigation with sub-surface drip irrigation.

Using multiple inlet irrigation rather than conventional irrigation showed a 6 savings in water run-off from rice fields, which represents a very large volume of water. Water use was reduced by 25 percent over three years with multiple inlet irrigation rice production combined with intermittent rice irrigation or with multiple inlet irrigation alone in another test. Surge valve irrigation in combination with the Phaucet Irrigation scheduling program for furrow irrigation reduced pumping by an average of 25%. Researchers found that improvements in sprinkler heads and end-gun delivery can improve uniformity of sprinkler irrigation application more than 20%. This will allow more accurate application of irrigation water. Reductions in nitrate nitrogen leaching below the root zone of vegetable systems have been measured at up to 70% when using soil moisture based irrigation control with multiple daily irrigation events compared to single timed irrigation events each day.

Stream flow was monitored to determine seasonal water flow variation in order to document water availability for small scale off-stream storage of water for agricultural use during the growing season. The elevation of the proposed pump station intake will be determined by continuous multi-year in stream stage monitoring. Water metering of surface water harvested and pumped through a two mile pipeline in use by a family farm for irrigation of over 600 acres of corn and peanuts since 1997 was initiated in early 2008. Volume of harvested water, acres irrigated, yields and water harvesting related expenses are part of an ongoing study of surface water harvesting costs for irrigation. The 3-year study ending in 2010 will be used to support the irrigation efforts to increase off-season off-stream water harvesting for irrigation.

Fertigation studies begun in 2006 evaluated the timing of nitrogen and potassium throughout the cotton growing season. Enhanced water use and reduced leaching of nutrients has not affected crop performance. First year results showed that N and K liquid fertilizer injected closer to the beginning of the season resulted in the highest yields. Results since 2007 have shown decreased yield performance in fertigated cotton treatments. Field excavation to determine the cause indicates that nutrient movement may be impeded as soil becomes more compacted in the years following drip tape installation. As a result, surface-applied nutrients may be more available to the crop than those applied through sub-surface lines. Continued long-term monitoring and soil nutrient sampling is needed to verify hypotheses. A subsurface irrigation system installed to land-apply swine effluent is in its second year of operation at a research station. The system is being used to evaluate agronomic and environmental performance against a traditional spray irrigation system.

Urban landscapes are increasing in acreage and populations involved (often with little experience and little economic incentive to improve management of this non-agricultural land use), and so the potential of this work in making it easy to reduce water wastage and environmental impact is great. Similarly, the ornamental industry is very important economically to this population throughout the region, and so efficiency improvements through technology application can have an important economic and environmental impact. Expanding use of disk rain sensors for residential landscapes has reduced water use more than 30% compared with time based irrigation scheduling with no sensors. In addition, soil moisture sensor irrigation controllers have been shown to reduce irrigation application nearly 90% without reducing turfgrass quality. Sensor controlled irrigation of turf reduced water use by more than 20 percent compared to a standard timer set to apply long-term average irrigation requirements, and in a residential study reduced water use by over 40 percent compared to a control group. Reductions in water use in urban settings were realized in urban lawns through better timing of applications and minor changes in landscape. By resetting clocks for timing urban irrigation, the researchers showed a 30% reduction in water use without major landscape changes. Incorporating micro-irrigated areas within the landscape design in urban lawns realized a 50% reduction in water use with the change in timing of irrigation. Incorporating an ET measure into the irrigation controller reduced water use by 40-60% under rainy conditions, and up to 30% under dry conditions.

Variable rate irrigation (VRI) technology is a relatively new concept in agriculture which applies irrigation water to match the needs of individual management zones within a field. It can lead to substantial water conservation while increasing crop yields. VRI technology is not commercially available for lateral irrigation systems. The new software and controller developed in this research will make the VRI lateral system more efficient for researchers and also growers. Automation of sensing/irrigation will allow timely irrigation decisions increasing yield and crop water use in cotton.

The UGA EASY pan, and other ET-based irrigation scheduling technologies have been implemented in Georgia, Mississippi, Arkansas, Louisiana, Missouri and a number of other states to get farmers more interested in irrigation scheduling, using approaches that require less labor and to provide a method for understanding irrigation scheduling characteristics. The goal of the system was to encourage benefits Research to improve system parameters has been implemented for a variety of crops. MOISCOT and MOISNUT (SuperCalc4-based computer irrigation scheduling spreadsheets using soil moisture, crop water use curves, rooting depth, and effective rainfall to schedule pivot irrigation of corn, cotton, and peanuts in the SE US) were transferred into an Excel application for individual and web-based irrigation scheduling. Additional research efforts updated the Arkansas Irrigation Scheduler to allow users to input reference evapotranspiration directly instead of allowing program to estimate, thus making program more adaptable to other growing environments.

Additional research was directed at the development and testing of variable rate irrigation and sensor technology. Real-time soil moisture measurements are essential for site-specific and automated irrigation systems. Researchers performed numerous tests of different capacitance moisture probes manufactured by Sentek and AquaSpy Inc. New software and controller was developed to make possible variable rate irrigation via linear-move irrigation system. Additional research was directed at developing rice production systems with center pivot irrigation. This research focused on development of water use functions and adapting the Arkansas Irrigation Scheduler to include rice.

A monitoring system was developed to alert farmers to the status of furrow or flood irrigation. The system tracks the status of the irrigation, and directs farmers when the irrigation can be remotely or manually turned off. The flood system also alerts farmers when it is time for another irrigation.

Objectives

1. Improve irrigation water application through automation, control, and application technology and sensor/communication systems to support that automation.
   
2. Improve irrigation water management with enhanced scheduling techniques employing robust field-sensor-based systems, locally derived crop coefficients, accurate estimates of actual and reference evapotranspiration, and improved accounting for effective rainfall
   
3. Enhance water supplies and reduce water quality impacts of irrigation management where rainfall is an important component of the water supply issue.
   
4. Enhance the transfer of irrigation technologies and management alternatives emphasizing economic and environmental benefits.
   

Methods

Objective 1 Procedures: Improve irrigation application through automation, control, and application technology and sensor/communication systems to support that automation. Unlike other areas of the country, the Southeast has ground water resources, and rainfall at times in excess of 40 per year. Continued and expanded use of irrigation has led to serious groundwater depletion, however, which threatens future cropping options (Bennett, 2002). The challenge for the region is to manage water resources appropriately and provide sufficient water for crop production during droughty periods that occur during the growing season. Increasing volatility in recent weather patterns has resulted in no change in overall rainfall amounts but a decrease in the number of events and a concomitant increase in intensity (SWCS Climate Change, 2003). These changes in rainfall patterns decrease the usable rain that enters the soil profile. Research under Objective 1 is designed to improve irrigation application technologies and methods. Sensors are being developed to track plant and soil moisture, and detect the onset of water limiting conditions. Incorporation of automated measurement technologies into irrigation systems and irrigation scheduling methods will be coordinated with research programs as outlined in Objective 2. 1a) Improved sensing of crop and soil conditions Improving water management depends on knowledge of crop and soil moisture status. Developing sensors that more reliably monitor moisture and detect the onset of crop water stress will allow more timely application of irrigation. Research will focus on developing sensors to monitor crop and soil status, and test the robustness and reliability of sensor and shutoff devices for irrigation control and automation. Substantial barriers exist in scaling up soil moisture sensor control systems for use on a commercial scale. These larger zones arent conducive to fine control based on soil moisture due to issues such as measurement representativeness and water travel time in the system. Types of soil moisture sensor (SMS) control systems will be tested for robustness and reliability for commercial scale. Soil moisture variability at the field scale will be determined to help estimate the minimum number of sensors needed along with optimal placement. Also, effectiveness of wireless soil moisture sensor nodes will be tested and low cost capacitive sensors will be calibrated. Soil moisture sensors will also be tested for applicability in detecting crop status in agriculture and residential irrigation. The use of timers and other devices to aid in surface irrigation management, particularly on rice production, will be investigated. Thermal imaging will be investigated for assessment of crop condition and spatially indicated temporal trends in canopy-air temperature difference and canopy cover. Thermal imagery datasets from irrigated fields in the Mississippi Delta will be used to determine problem field areas that exhibit consistently high potential for crop water/heat stress. Other applications for processed thermal data will include: scheduling of water application (used in concert with ground-based readings of soil moisture status and canopy temperature); detection of leaking irrigation canals; and gauging water distribution in furrow irrigation. These are somewhat different approaches to the use of thermal imagery in humid regions compared to those previously used. 1b) Improved application systems Because of historically readily available water resources, fairly inefficient irrigation methods such as furrow, seepage and other surface irrigation methods are still commonly used in humid regions. Better management of water resources is possible through increased implementation of more efficient irrigation methods, including sub-surface drip and sprinkler systems. The use of sprinkler systems in place of traditional, less-efficient flood irrigation will be investigated for rice. The feasibility of using sprinkler and drip-irrigation systems on more specialized and often non-irrigated crops such as sweet potato will be assessed. Alternative irrigation systems such as sprinkler and drip irrigation will be investigated and compared to traditional seepage irrigation for potato in Florida. The effect of irrigation on yield will be determined and the information generated will be used to assess the economic benefit of adopting irrigation systems. This information could be used to develop an advisory system that will allow growers to optimize their production systems and improve profitability. Researchers will work with producers as outlined in Objective 4 to transfer the knowledge and technologies to growers. Most important in modern vegetable production systems is the use of drip irrigation under plastic mulch and fertigation, i.e., the addition of nutrients through the drip system. Although drip irrigation has been an important benefit to the fruit and vegetable industry in the southeast, many challenges confront the efficient management of this technology. Vegetable growers must make decisions on how frequently to irrigate and how long to run their system each time. Most vegetable growers lack adequate sensing technology and on-the-fly data interpretation capabilities to do effective irrigation scheduling. Typical irrigation cycles are usually longer than necessary and thus wasteful of water, energy used for pumping, and money paid for leached nutrients. To address the needs of the vegetable growers, researchers are studying the utility of multi-sensor soil capacitance probes for tactical (real-time) scheduling in drip irrigated melons in sandy soils. Their study has gained considerable popularity among growers as evident by their enthusiastic participation and engagement at field days and training workshops. Their goal is to partner with technology providers to deploy and test the performance of the automated, sensor-based drip systems on-farm. 1c) Site-specific applications Site-specific application technologies will be developed to better match water use with potential economic return. Applying precision irrigation technology to agronomic crops will be studied by incorporating soil-moisture sensing and wireless data transmission into variable-rate irrigation systems as an alternative to map-based control. These technologies will examine variable rate irrigation for water application efficiency, crop production, and economic return. 1d) Wireless remote monitoring and control systems Systems which transfer sensor-based data wirelessly from the field to office/internet/phone and into a form from which irrigation decisions can be made will likely be an important and desirable component for producers using sensor-based systems. The practicality and economic feasibility of in-field sensing and wireless transmission for automating data collection will be assessed. Investigation of "smart" irrigation technologies for differences in applied water and quality will continue in both crop production and turf. Two studies are already in progress evaluating water use before and after intervention with smart technologies for turf. These same technologies could be adapted to apply to crops. Objective 2 Procedures: Improve irrigation water management with enhanced scheduling techniques employing robust field-sensor-based systems, locally derived crop coefficients, accurate estimates of actual and reference evapotranspiration, and improved accounting for effective rainfall. Multiple approaches will be addressed with the fundamental desire to simplify the irrigation scheduling process for improved adoption by producers and consultants. The importance of deficit irrigation will be explored as a sound demand management strategy to mitigate intermittent drought and in locations with limited water availability. Crop physiological responses to irrigation will be measured and/or modeled for different crops, irrigation regimes, soils, and tillage methods to determine their relationship to crop water use, yield, and economic return. Plant responses at various physiological stages and will be measured using replicated field trials and standard research practices. These data are essential to the development of systems for more accurate irrigation management, with added characterization based on irrigation type and soil conditions. Testing over multiple years on replicated field sites will be used to identify promising strategies, technologies, and modeling approaches. Results from these field studies will be incorporated into web-accessible systems associated with real-time weather data from weather station networks. Other implemented approaches will be based on limited climatic data and on long-term analysis with historic weather data. 2a) Field sensor-based approaches to irrigation scheduling will be enhanced and tested at larger scales than done during the development phase outlined in Objective 1. Systems which transfer sensor-based data wirelessly from the field to office/internet/phone and into a form from which irrigation decisions can be made will likely be an important and desirable component for producers using sensor-based systems. Sensors and systems developed in Objective 1 will be refined and tested for utility in production irrigation, as well as off-the shelf sensors and systems already available. Reliability, affordability, longevity, minimum interference of field operations, and ease of use will be important characteristics. Systems are expected to include a host of sensors including: soil moisture monitoring (e.g., Sentek, Watermark, Echo, EarthTec, AquaSpy, Delta-T, and Acclima); plant-based sensors such as wired and wireless IR temperature monitoring (e.g., SmartCrop); sap flow sensors; and less intensive approaches such as an atmometer or UGA EASY Pan. New/innovative field sensors will be used in replicated field trials or demonstration sites for selected soils and crops (e.g., cotton, corn, peanut, soybean, rice, and vegetables) that are prevalent in the humid Mid-South and Southeast. Crop yields, total water applied, and economic returns will be determined for comparing approaches to aid in irrigation diagnostics. The appropriateness of various sensor-based scheduling methods and their practical utility and cost-effectiveness will be determined for various irrigation systems (i.e., surface, sprinkler, and surface and subsurface drip). 2b) Development and selection of crop coefficients will include critical assessment of different methodologies for improved calculations under local and regional conditions. Methods for developing crop coefficients will include automated weighing lysimeters, reflectance and photographic methods, and soil water budgeting to estimate crop water use. 2c) Development of alternative reference evapotranspiration (ET) estimation methods will seek accuracy comparable to the Standardized Penman-Monteith while recognizing that many parts of the region still have limited real-time climatological data available to farmers. 2d) Accurate field-specific rainfall values are difficult to obtain with the high degree of spatial variability observed in humid and sub-humid regions. Furthermore, recognizing the portion of a rainfall event that contributes to lowering the soil water deficit (i.e., effective rainfall) has always been an additional challenge. Retrieval of Doppler rainfall information for more intensive analysis of incident rainfall conditions, remote sensing data for spectral response, and modeling approaches combined with soil sensor studies to estimate effective rainfall will all be implemented for greater detail in the crop ET determinations and water balance calculations to reduce potential errors in the calculations. Objective 3 Procedures: Enhance water supplies and reduce water quality impacts of irrigation management where rainfall is an important component of the water supply issue. Historically in humid and sub-humid areas water supplies were considered practically inexhaustible. Compared to arid regions, groundwater was shallow and easily accessible, while many streams and rivers flowed year round. However, groundwater and surface water shortages have been experienced throughout the area. Furthermore, endangered species, water quality standards, and the rights of downstream users have all affected water supplies available for irrigation. Much opportunity exists for sharing knowledge among cooperators in several projects, demonstrations, and technology transfer activities spread throughout the area. The efforts under this objective will be to foster communication and increase the opportunities to share concerns, solutions, technologies, and project experiences; successful operations and practices will be continued and expanded where possible. Some examples of successful local efforts that will be continued include: . Off stream storage reservoirs are being investigated for enhancing water supplies for irrigation. Stream flow at the Blackbelt Research and Extension Center has been monitored to determine seasonal water available for off-stream storage during typical wet winter months and subsequent agricultural use during the growing season. . Studies have been initiated to determine the storage and yield potential for on-farm ponds and for larger reservoirs. Most ponds rely upon rainfall and runoff, but a smaller number intercept perennial streams and springs. Of ponds used for irrigation approximately 20% are refilled from groundwater sources, exposing groundwater to evaporation before the water can be pumped to the irrigation field. The cumulative impact of their function on water flow is one of the study objectives. . Measuring water applied, and the runoff on 10 tailwater pits that have been instrumented to measure the depth (runoff volumes), water pumped from the pit to the reservoir (partial water out), and runoff. Water samples (grab samples) are taken at various times to look at sediment concentration. . Utilizing SPAW (an irrigation model) as the basis for the development of a practical model that is easy to use that performs a daily water balance for any particular farm or location. This includes daily rainfall, daily runoff, daily irrigation needs (if any), water pumped to storage reservoirs, water pumped out of storage reservoirs, and when pump capacity is exceeded or the reservoir is full. Runoff is calculated as well as irrigation return efficiency. This gives a daily water balance for that farm, including any runoff. Efforts are underway to develop a GIS based product, using annAGNPS (a soil model). . Determination of water quality impacts from rice irrigation at a field and micro-watershed scale. This is multi-year project. . Alternative management practices, such as deep tillage (sub-soiling) or incorporating cover crops will be used to examine the impact on soil available moisture and irrigation needs. Cover crops may be used to increase water infiltration and improve water holding capacity in sandy soils. The economics of alternative management practices and irrigation will also be determined. 3a) Establish a communication network to facilitate technology and information exchange. " Develop and publish a list of specialists that could serve as a technology resource for surface water concerns and water quality issues; participants would provide information related to: . who am I . what do I do to help " Develop and implement a method to easily post questions, share information, post presentations, identify reports, and post results of local projects. This would be linked to the S1018 webpage. 3b) Schedule tours among interested groups to visit the projects. This will be done in conjunction with S1018 annual meetings when possible, but additional meetings will be scheduled as appropriate. Objective 4: Enhance the transfer of irrigation technologies and management alternatives emphasizing economic and environmental benefits Technology transfer of irrigation technologies to clientele (farm, nursery, landscape and turf) will include development of local and regionally applicable publications that are integrated across engineering, crop management and economic disciplines; implementation of multi-disciplinary field days (involving irrigation, hydrologic, and economic specialists) to demonstrate practices; development of regional and national workshops to create a curriculum for an area specialty in irrigation; regional in-service training of extension agents, irrigation dealers, and consultants; incorporation of ET standards into local and state weather networks (with effective precipitation estimation); and help in selecting appropriate locations for SCAN (Soil Climate Analysis Network) systems within the nationwide network operated by NRCS. Efforts are underway to install and operate the first state-of-the-art network of agricultural meteorology stations (SCAgMet) with cellular IP-assigned communication capabilities for data retrieval, automated data quality control, and post processing for web-based dissemination of the meteorology data as well as irrigation and crop management information. Lessons-learned in the design and installation of other networks are guiding this endeavor. An understanding of appropriate and accepted terminology for irrigation efficiency is expected to be provided within this objective that can allow inclusion in publications. Use of similar terminology by project participants will enhance the ability for understanding and implementing improved irrigation practices in humid and sub-humid areas. Major extension activities related to irrigation fall into four major areas: a) Irrigation Field Development of Irrigation Controllers; b) Irrigation Scheduling; c) Irrigation Contractor Education Programs; and d) Irrigation Pumping Efficiency Testing. These programs address agricultural, horticultural and landscape irrigation systems. 4a) Field Development/Evaluation of Irrigation Controllers Irrigation controllers are developed and evaluated in Objectives 1 and 2 to automatically control irrigation on both landscape applications as well as drip irrigate vegetables. Extension specialists will continue to develop educational materials to add to existing fact sheets, videos and narrated PowerPoint resources. 4b) Irrigation Scheduling Education Resources Deliver decision support tools developed under Objectives 1 and 2 to producers for scheduling irrigation of agronomic crops. Irrigation scheduling is still an afterthought by most producers. Low-tech scheduling techniques will focus on the use of soil-water measurement methods and the use of regional setpoints/trigger points due to variations in rainfall and the complexities of estimating crop coefficients. Researchers at several locations are working collaboratively to develop and deliver irrigation scheduling tools. MOISMIS, a sensor-growth curve-web-based moisture monitoring and irrigation scheduling program, uses soil moisture tension-developed available soil moisture, crop water use curves, rooting depth, and effective rainfall to schedule pivot irrigation of corn, cotton, and peanuts in the SE US. The application will be used to support Alabama AWEP participants efforts in Irrigation Water Management of pivot irrigation systems supplied water from AWEP-funded off-stream storage structures. Web-based irrigation scheduling tools are being developed for cotton, corn, soybeans and sweet potatoes. The sweet potato scheduler is based off a Bayesian network (BN) model developed by sweet potato agronomists from across the country. The tools rely on automated downloading and transfer of data, such as weather information, and seamless integration of existing national databases to make the tools easier to use. In addition to the development of the tool, end-user training for the scheduler will facilitate its verification on 4-6 crop farms. During this verification program, Extension specialists will assist producers in testing the tool and provide feedback so that the development team can make appropriate revisions prior to launching the scheduler publicly. The tools will be delivered to producers through commercial technologies such as iPhone and other internet-accessible systems, allowing producers to make decisions in the field. 4c) Irrigation Contractor Education Programs Irrigation Contractor continuing education programs have been developed in North Carolina and Louisiana. A two-day Irrigation Basics education program has been developed to review and prepare contractors for the state examination. Workshops are conducted annually, or on an as-needed basis if there are a large number of individuals seeking certification. Extension personnel from NC and LA have shared and will continue to share their respective materials as they are developed. 4d) Irrigation Pumping Efficiency Testing Irrigation pump test evaluations are critical for accurate application of irrigation water, and are an important consideration of the irrigation scheduling tools being developed under Objective 2. These evaluations will be conducted on farms, for both diesel and electrically powered pumps. Ultrasonic flow meters will provide accurate estimates of the well output (gallons/min). During tests on diesel pumps the fuel usage (gallons/hour) will be reported at various speeds (RPM). Where applicable, a torque cell will be installed between the motor and the gear head to calculate the output horsepower. At the end of each pump evaluation a report will be prepared and printed on-site and given to the producer. All the data collected will allow producers to answer five (5) very important questions: 1. How much water is being delivered at various operating speeds? 2. How much fuel is being used at various operating speeds? 3. What operating speed provides the most economical pumping rate? 4. Is my power system (diesel or electric) operating within normal ranges? 5. Is my pump operating within normal operating ranges? Approximately 100 pumping systems will be evaluated each year. Data from 2008 studies resulted in an average savings of approximately $5,555 per year for diesel pumps. This would equate to a potential savings of over $1,310,000 for the Louisianas rice industry in one year. A series of 6 three-day workshops on irrigation pumping plant efficiency testing will be conducted across the Southern Region. The workshops will focus on the methods of conducting evaluations, their benefits related to water, energy and operating costs, and the cost of equipment recommended for conducting evaluations. Workshops will be conducted through classroom presentations, hands-on field evaluations, and classroom labs where participants will manipulate field data both manually and through a standardized spreadsheet. Training workshop agendas will include an overview of planned measurements, safety, computations, troubleshooting and discussion of areas for water conservation. The workshops will be targeted to irrigation and drainage districts, conservation districts, NRCS, cooperative extension, well installers, irrigation companies, and producer groups. To support the three-day workshops, a series of factsheets will be developed. Topics may include: Benefits of Pumping Plant Efficiency Tests; Measuring Irrigation Flow; Implementing Irrigation Water Management Plans; Irrigation Water Conservation Practices; Reading Digital Electric Meters; Measuring Diesel Fuel Use; and, How to Conduct a Pumping Plant Efficiency Test. Copies of the factsheets will be posted on the web, via the Southern Region Irrigation Water Management team.

Measurement of Progress and Results

Outputs

• measures of products or services to be produced by the activity This regional project will make available a comprehensive set of baseline data and information, including daily and seasonal crop water use, crop coefficient, yield production functions (i.e., yield versus irrigation), and threshold soil water depletion levels for major row crops and vegetables across the Southeast. The regional efforts will also make available new or newly modified irrigation water management and scheduling models that are made applicable to southeastern row crops, vegetables, soils, and climate. The project will provide assessment of the suitability of various irrigation scheduling methods for use by producers and action agency personnel across the Southeast. Our findings will be made available online, documented in refereed and conference articles and extension publications, and will be presented to the public via national and local conferences and the internet.

Outcomes or Projected Impacts

• Assess the results (impacts) of the activity compared to its intended goal(s) A major emphasis in this regional project is to encourage proven approaches that maximize the net economic and environmental benefits of irrigation. Providing growers with advance irrigation concepts, systems and management tools through an integrated and regional research and extension program as well as strengthening their on-farm managerial capabilities will help to effectively address shortcomings in current irrigation practices. The outcome will be water and energy conservation for individuals and communities, reduced environmental degradation via reduced leaching of chemicals with societal benefits, and enhanced rural livelihoods through increased farm profit due to higher yields and product quality.
• Impacts will be enhanced regional and multi-agency collaboration; increased knowledge and understanding of improved irrigation water management practices; reduced irrigation water use and thus increased energy conservation and/or increased production yields through improved efficiency; decreased competition for water by identifying alternative water supplies and/or utilizing demand management strategies; encouraging water re-use, and promoting water-conserving system designs; reduced contaminant loading to surface and ground waters.

Milestones

Projected Participation

View Appendix E: Participation

Outreach Plan

This proposed activity will address irrigation needs of small and large water users alike. One over-riding objective is to encourage economical approaches to technology and management so that size of the operation does not preclude adoption of the developed and transferred approaches. Participation from 1890 land grant institutions and technology transfer personnel associated with small and limited resource farmers will be encouraged through participation in TA (team agriculture) programs.

Organization/Governance

Literature Cited

Bennett, D. 2002. Balancing demands for water. Delta Farm Press, April 16, 2002. available online at: http://deltafarmpress.com/news/farming_balancing_demands_water/index.html

Counce, P.A. 2008. Draining rice by growth stages on the Grand Prairie  a predictive computer program. Arkansas County Conservation District Newsletter.

Counce, P.A. K.B. Watkins, K.R. Brye and T.J. Siebenmorgen. 2008. A model to predict safe rice field draining dates and field tests of the model predictions in the Arkansas Grand Prairie. Proceedings of the 32nd Rice Technical Working Group Meeting held in San Diego, CA. (In Press)

Counce, P.A., T.J. Siebenmorgen and K.B. Watkins. 2008. A model to predict safe stages of development for draining rice fields. Pp. 151-156. In R.J. Norman, J-F.C. Meullenet and K.A.K. Moldenhauer (Eds.) Rice Research Series 2007. University of Arkansas Agricultural Experiment Station Research Series 560.

Dougherty, M., AbdelGadir, A.H., Fulton, J.P., van Santen, E., Curtis, L.M., Burmester, C.H., Harkins, H.D., and B.F. Norris. 2009. Subsurface drip irrigation and fertigation for North Alabama cotton production. Journal of Cotton Science 13:227-237.

Dougherty, M., Welsh, R., King, S., and E. Vis. 2009. Teaching landscape irrigation design to non-engineering college students. ASABE Journal of Applied Engineering in Agriculture. 254 (2):299-310.

Dougherty, M., AbdelGadir, A.H., Fulton, J.P., Burmester, C., and L. Curtis. 2009. Subsurface drip irrigation for site-specific, precision management of cotton. Paper #2176 In Proceedings of the Irrigation Association 2009 Technical Conference. December 2-4, 2009, San Antonio, TX.

Dougherty, M., AbdelGadir, A.H., Fulton, J.P., Burmester, C., and L. Curtis. 2008. Sprinkler irrigation for site-specific, precision management of cotton. Paper #2176 In Proceedings of the Irrigation Association 2008 Technical Conference. November 2-4, 2008, Anaheim, CA.

Dukes, M.D., D. Haman, F. Lamm, G. Grabow (editor). 2008. Site Selection for SDI Systems in North Carolina. Bulletin AG-695-2, North Carolina Cooperative Extension Service.

Dukes, M.D., D. Z. Haman, R. O. Evans, G. Grabow (editor), K. Harrison, A. Khalilian, W.B. Smith, D. Ross, P. Tacker, D. Thomas, R. Sorenson, E. Vories, H. Zhu. 2008. SDI Considerations for North Carolina Growers and Producers. Bulletin AG-695-1, North Carolina Cooperative Extension Service.

English, P.J., DeFauw, S.L., Thomson, S.J., Smith, J.W. 2008. A new method for the detection of heat/water stress in irrigated cotton using thermal imagery. Proceedings of the Beltwide Cotton Conferences, Nashville, TN, January 8-11, 2008. Abstract.

Farahani, H. J., A. Khalilian and B.W. Smith. 2008. Irrigation water management in South Carolina  trends and needs. Proceedings, 2008 South Carolina Water Resources Conference, October 14-15, 2008, Charleston, SC.

Fisher, D.K. Automated collection of soil-moisture data with a low-cost microcontroller circuit. Applied Engineering in Agriculture. 23(4):493-500.

Grabow, G., K. Harrison, M.D. Dukes, E. Vories, W. B. Smith, H. Zhu, A. Khalilian. 2008. Design and Installation of SDI Systems in North Carolina. Bulletin AG-695-3, North Carolina .

Haman, D., R. Sorenson, D. Ross, G. Grabow (editor), and R. O. Evans. 2008. Critical Management Issues for SDI Systems in North Carolina. Bulletin AG-695-4, North Carolina Cooperative Extension Service.

Hanks, J.E., G.D. Wills, F.A. Harris, E.J. Jones, and D.K. Fisher. 2005. Precision Agriculture Technologies for Cotton Production. In Proceedings of the Beltwide Cotton Production Research Conference, New Orleans, LA, 4-7 Jan 2005. National Cotton Council, Memphis, TN.

Khalilian, A., Y.J. Han and H.J. Farahani. 2008. Site-specific irrigation management. Proceedings, 2008 South Carolina Water Resources Conference, October 14-15, 2008, Charleston, SC.

Miller, G., H.J. Farahani, D. Lankford. 2010. Set Points for Watermelon Drip Irrigation Using Capacitance Probes. Third International Symp. Soil Sensor Conference_Spain April 2010

Muñoz-Carpena, R. and M.D. Dukes. 2005. Automatic irrigation based on soil moisture for vegetable crops. Fact sheet ABE356, University of Florida, Institute of Food and Agricultural Sciences, Cooperative Extension Service, Gainesville, FL.

Sheffield, R.E. and D.L.Thomas. 2008. Subsurface drip irrigation in the southeast. Louisiana State University AgCenter. http://www.lsuagcenter.com/en/crops_livestock/crops/Irrigation/

Soil and Water Conservation Society. 2003. Conservation implications of climate change: Soil erosion and runoff from croplands. Soil and Water Conservation Society, Ankeny, IA. 24 pp.

Vasanth, A., G. Grabow, D. Bowman, R.L. Huffman, and G. L. Miller. 2007. Evaluation of Evapotranspiration-Based and Soil-Moisture Based Irrigation Control in Turf. In: Proceedings of the 28th Annual International Irrigation Show, Dec. 9-11, San Diego, Calif. ISBN: 9781605600987.

Vories, E.D., Fisher, D.K., Tacker, P.L., Sudduth, K.A. 2007. Using wireless technology to reduce water use in rice production. Proc. Fourth Int. Conf. on Irrig. and Drainage. Denver, Colo. USCID:471-480 [CDROM]

Attachments

Land Grant Participating States/Institutions

AR, LA, MS, NC, SC

Non Land Grant Participating States/Institutions