Brief Summary of Minutes of Annual Meeting

Accomplishments: Objective 1. Coordinate development of delivery methods for the dissemination of climatic based irrigation scheduling. o Determined a list of USGS gauging station that could be potential weather stations for adding additional sensors to these stations for a more complete network. o The remote-sensing group at UC Davis has nearly completed a GIS based ETo map for California. It is planned to publish the map in the near future. o Reclamation, in partnership with the USDA NRCS, installed a new AgriMet station in the Klamath Basin in Oregon (Sprague River near Beatty) to help support Irrigation Water Management activities in the basin. The station was installed in October, 2004. o Numerous enhancements were made to the AgriMet website in 2005 http://www.usbr.gov/pn/agrimet. o The NDAWN website at North Dakota (ND) State University http://ndawn.ndsu.nodak.edu/applications.html has been completely revamped. o Training sessions on irrigation water management have been held for NRCS personnel, Technical Service Providers and irrigators at several locations in North Dakota. o An irrigation-scheduling program for the Palm operating system has been developed and is currently being used by several irrigators at various locations across North Dakota. o AZSCHED Version 1.13 (V1.13) (AriZona irrigation SCHEDuling) program, is now available on-line to download onto personal computers developed by the University of Arizona. o AZSCHED V2.0 and is being tested in-house. o The AgriPartner program of Texas Cooperative Extension summarized on-farm irrigation and dryland demonstrations where the NPET models and data were again validated in 2004-2005. o Texas A&M efforts entailed continuing operations and maintenance regarding the Texas High Plains ET network (TXHPET). o An Urban Landscape Water Conservation Coordinating Committee (Dr. Rolston St. Hilaire  President, Dan Smeal - Secretary) was formed in New Mexico to coordinate knowledge and activities connected to desert landscaping and water conservation. o The ULWCCC is organizing a March 2005 conference in Albuquerque pertaining to water conservation in arid landscapes. Objective 2. Coordinate identification of existing climate based irrigation scheduling methods or tools. o Developed a modified SEBAL calculator for using ASTAR data to measure ET. o Work by R.L. Snyder and S. Eching on the Landscape Irrigation Management Program (LIMP) added the ability to adjust landscape coefficients for slope and aspect to the application program. o The AgriMet program by USBR is working to implement an on-line irrigation scheduling program in the Pacific Northwest. o A water utilization project using irrigation to reduce the amount of water draining into Devils Lake, North Dakota (a closed basin with no outlet) has just begun. It plans to use a variant of SEBAL to analyze the water use in the basin using satellite imagery. o The Percent Canopy Cover (PCC) as suggested by Ted Sammis of New Mexico is implemented. Work is being done in Yuma to test this tool (use of PCC) and its application in AZSCHED. o A literature review of crop coefficients and other techniques for managing irrigations on turfgrass has been implemented. Objective 3. Coordinate acceptance of a standardized reference evapotranspiration equation. o Presented reference evapotranspiration equation on New Mexico climate network web site and showed comparison of old reference Et to new Et equations. o In California, the ETo equation of Pruitt and Doorenbos (1977) is used in CIMIS. However, hourly estimates of ETo from the standardized reference evapotranspiration equation are provided by CIMIS for use by sophisticated growers, researchers, and engineers. o AgriMet program by USBR is developing software to implement new standardized reference ET equation. o The ASCE standardized reference ET equations (ETrs and ETos) were compared to the Jensen-Haise and the NDAWN reference ET (Penman based) equations. Weather data from the Carrington NDAWN site from the 1992, 1996 and 2002 growing seasons (May 1  September 30) were used for the comparison. The Jensen-Haise reference ET values (used for irrigation scheduling in North Dakota) had a much better fit to the standardized ETos equation than the NDAWN reference equation but didnt fit the ETrs equation very well. However, the NDAWN reference ET equation fit the ETrs values very well. o Preliminary comparisons of the newly drafted ASCE ETo equation on an hourly basis to that of daily computations has generally agreed to a multiple digit level with regards to daily summations. Coordinated corrections and clarifications of the ASCE/EWRI standardized reference evapotranspiration manual through trial calculations to verify the 15º solar angle cutoff on hourly solar radiation for nighttime Rs/Rso with Drs. Richard Snyder and Richard Allen. Final verifications of the hourly computations have not been made against the spreadsheet calculator of Rick Snyder due to changes made to the spreadsheet recently (past week), although previous comparisons were nearly identical. All research papers have typically included both ETos and ETrs, but crop coefficients have been expressed mainly on ETos. Objective 4. Coordinate the identification and documentation of crop coefficients used in irrigation scheduling and the methods by which coefficients are moved forward in time (accumulated heat units, % crop cover, time, etc.). o Crop coefficients for creosote ornamentals was accepted for publication in Agr. Water Management. o A visitor from Egypt (Atef Ghandours) has been working with R.L. Snyder at U.C. Davis to accumulate literature on crop coefficients for use by the EWRI task committee on crop coefficients. Three studies on the crop coefficients of citrus were published and work on the Kc values for onions was initiated. o Crop coefficients for the 10 most irrigated crops in North Dakota were developed many years ago for use with the Jensen-Haise reference ET equation based on days past emergence (DPE). The crop coefficients for potatoes were checked as part of other ongoing research and generally found to be correct. o Working with the BOR staff in Yuma, new crop water use data to verify the data already used in AZSCHED for citrus are developed. o Crop coefficients for cotton were developed and will be published soon (Aug./Sept. issue) in Journal of Irrigation and Drainage Engineering (ASCE) and crop coefficients were presented at a 2004 ASAE/CSAE meeting. All NPET crop development models and Kc data are based on GDD models for wheat, sorghum, corn, cotton, peanut, and soybean for the Texas High Plains. Several of these Kc data are being used by groundwater districts successfully in Kansas. o ET of cool season and warm season turfgrass cultivars was measured in 2005 at the Farmington ASC for calibration of turfgrass crop coefficients developed at the site in 2001. o Water requirements of drip-irrigated, drought-tolerant (xeric) landscape species (96) in a xeriscape demonstration garden were evaluated. Irrigation treatments were 0, 20, 40, and 60 percent of Penman-Monteith (FAO-56, tall) reference ET. o Water requirements of drip-irrigated vegetables (tomatoes, chile peppers, and sweet corn) were investigated. A randomized, replicated (3) plot design with three irrigation treatments: 50, 75, and 100% of FAO-56 PM reference ET was used.