Brief Summary of Minutes of Annual Meeting

Because of several new participants and a few new members, the Administrative Advisor provided a summary of the history and purpose of WCC-202. The process for joining a regional committee was also summarized. Representatives from each state, federal agency, and private firm attending the meeting gave reports on their activities. Individuals participating in this committee are heavily involved in gathering weather data and providing crop water use information that is crop and weather station specific.

The main action items from this annual meeting were:

Committee members are to send Ted Sammis the URLs for their irrigation scheduling Web sites as well as information on crop coefficients.

Each state is to compare their method of ET computation against the new standardized ET procedure using Richard Snyders Excel spreadsheet that has the standardized method, which is available on his Web site (http://biomet.ucdavis.edu).

Kelly Kopp will chair a committee to begin development of an Irrigation Scheduling 4-H Educational Curriculum. Committee members include Ted Sammis, Joe Henggeler, Mahbub Alam, and Danny Rogers. Dan Smeal will look into participation by the Farmington, NM County Agent.

Ed Martin was nominated and selected for secretary beginning at the conclusion of this meeting, and to take over as President at the conclusion of the 2004 meeting.

Joe Henggeler (chair), Ed Martin, Mahbub Alam, Tom Marek, and Danny Rogers will serve on a subcommittee to review irrigation scheduling software.

Next meeting of WCC-40 will be in Boise, Idaho in mid-May 2004.

Obj. 1. Development of delivery methods for the dissemination of climate based irrigation scheduling.

California Department of Water Resources upgraded the California Irrigation Management Information System (CIMIS) Web site to be more user-friendly at http://www.cimis.water.ca.gov

The Biometeorology group at UC Davis has created a new Web page with information on how to obtain evapotranspiration information, how to determine crop coefficients, and how to schedule irrigation at http://biomet.ucdavis.edu

Maintain interactive Internet site to construct Woodruff irrigation charts at
http://agebb.missouri.edu/irrigate/woodruff

Developed Internet-based guidelines on when to apply last irrigation on corn and soybeans at http://agebb.missouri.edu/irrigate/tips/index.htm

Developed Internet-based database of historic rainfall for Missouri at http://agebb.missouri.edu/weather/history/index.asp

Maintain the crop water use website at http://ndawn.ndsu.nodak.edu/applications.html. Crop water use maps and numerical tables for the 60 weather stations on the North Dakota Agricultural Weather Network (NDAWN) are updated daily during the growing season. In 2001, a cumulative rainfall map was added to the site, in 2002, a rainfall minus crop water use map for corn was added to identify water deficient zones in the state. Access to historical crop water use tables was also added to the NDAWN Web site.

Continue to maintain and update the NDSU irrigation Web site at http://www.ag.ndsu.nodak.edu/abeng/irrigation.htm.

A working prototype of a PDA based irrigation scheduling program using the Palm handheld has been developed and will be tested during the 2003 season.

Several articles were published in the NDSU irrigation newsletter, Water Spouts, concerning irrigation scheduling and water management for dry beans, corn, potatoes and alfalfa.

A soil moisture sensor measuring demonstration model was developed for use at irrigation field days and workshops to check if climate based irrigation scheduling methods are accurately predicting crop water status.

The US Bureau of Reclamation operates a network of 70 automated agricultural weather stations in the Pacific Northwest region, and 21 stations in the Great Plains region in Eastern Montana. Both regions post current weather data and crop water use information daily at:
PN Region: http://www.pn.usbr.gov/agrimet
GP Region: http://www.gp.usbr.gov/agrimet/agrimet.htm

AgriMet produces crop water use charts that are crop specific and station specific. Close coordination with local crop contacts (extension agents, crop consultants, etc.) to tie local crop development conditions to crop curves.

New stations: 11 new stations were installed in the Pacific Northwest region in 2002; One new station was installed in 2003, and two existing stations will be upgraded with the sensors required to model evapotranspiration.

A new AgriMet station installed in Bend, Oregon, will be interfaced with a Rainbird/Maxicom irrigation scheduler to automatically schedule irrigations for turfgrass managed by the City of Bend Department of Public Works.

Several rural agricultural newspapers publish AgriMet crop water use data during the growing season. Crop water use data is further disseminated by working relationships with County Extension Agents, NRCS technical specialists, Soil and Water Conservation District specialists, and agricultural consultants.

The USBR is working with CSU Fresno Center for Irrigation Technology on Wateright: An Educational and Irrigation Scheduling Resource for Water Managers (http://www.wateright.org). This Web site (under development) allows the user to input specific information about their crops and irrigation systems while tying into AgriMet or CIMIS for crop ET information.

The Texas North Plains Evapotranspiration Network (NP ET) continued to operate and incorporated the Texas AES/CE stations at Halfway, Lubbock, and Lamesa formerly operated by the Texas South Plains group (cooperating with Dr. Dana Porter). These stations were repaired, calibrated, and reprogrammed to meet NP ET criteria. New stations in the Texas Rolling Plains at Munday and Chillicothote were incorporated into the NP ET (in cooperation with David Bordovsky). A new Web site with hourly and 24-hr data access through a database is nearing completion (http://txhpet.tamu.edu). The network has experienced funding difficulties and held several meetings with clientele and political groups to secure short-term funding until more permanent funding might be obtained.

A newsletter was distributed to over 700 subscribers [see http://www.cprl.ars.usda.gov/wmru/pdfs/WF-Vol5-No1.pdf].

Obj. 2. Identification and verification of existing climate based irrigation scheduling methods or tools.

Many research projects by University of California faculty, extension specialists and farm advisors and USDA ARS researchers are related to determining crop coefficients and to regulated deficit irrigation, plant based measurements, and water use of tree crops, vine crops, field and row crops, and landscape vegetation.

UC and CDWR have jointly developed the SIMETAW program to simulate weather data, calculate the ASCE standardized ETo, apply crop coefficients, estimate ETc and effective rainfall and to determine the ET of applied water (ETaw) for long range water resource planning.

UC and CDWR have jointly developed the Consumptive Use Program (CUP) for determining historical average water requirement estimates and to provide crop coefficients to water districts and growers, and the Basic Irrigation Scheduling (BIS) program for calculating site-specific irrigation schedules using both historical average and current ETo data.

Conduct 2nd year of research on cotton and soybean using 8 scheduling methods computer program [Arkansas Scheduler], Woodruff charts, infra-red temperature, gypsum blocks, tensiometers, tub evaporation, visual symptoms, and graphical shape of soil moisture data). A dryland check was also included.

Conducted 2nd year of research on corn, cotton & soybean using 5 different deficit amounts. The Arkansas Scheduler was used to determine when to apply.

Surveyed irrigators regarding irrigation scheduling data.

Several types of soil moisture measuring apparatus were installed in research plots. Data were used to verify scheduling methods.

Soil moisture blocks connected to a MK Hansen monitor were installed in eight potato grower fields. Results were used to check irrigation water management and how it affects disease development. Crude estimates of water use were obtained.

Development of laboratory calibration methods for several types of soil moisture measuring devices. The resistance types of soil moisture sensor are difficult to calibrate over the useful soil moisture range and they are temperature dependent. These difficulties are causing problems in some irrigation research projects.

Three weighing lysimeters were completed at Uvalde, TX to validate reference grass ET models for south Texas and to develop crop coefficients for row and vegetable crops. This installation is directed by Dr. Giovanni Piccinni, Asst. Professor [see http://uvalde.tamu.edu/staff/piccinni/index.html].

The AgriPartner program of Texas CE [Drs. Brent Bean and Carl Patrick and Leon New, O.R. (Reggie) Jones (Coordinator), and Don Dusek] has summarized over 93 on-farm irrigation and dryland demonstrations where the NP ET models and data were validated in 2002. The total evaluations follow: corn 17, cotton 15, forage/silage 7, peanut 6, sorghum 17, sunflower 2, wheat 17, soybean 11.

These on farm demonstrations tracked applied irrigation water, rainfall, soil water use, yields, and crop phenology on each field (pivot, drip or furrow irrigation). The models performed well, except cotton on the Northern Texas High Plains. The cotton model is being revised for the higher elevation, shorter growing season. Seven part-time AgriPartner employees acquired the data on the various farm fields from 70 cooperating growers (10,725 ac.). Due to Texas budget shortfalls, 2004 AgriPartner employees will likely be reduced to 4 or 5 impacting this effort.

Obj. 3. Coordinate the acceptance of a standard reference evapotranspiration equation.

The CIMIS now calculates ETo using the hourly Pruitt-Doorenbos (1977) equation (PD) and the ASCE standardized ETo equation (PM) for short canopies as presented by Walter et al. (2000). The PD equation was retained to allow comparison with the PM equation for a few years, but both ETo estimates are made available on the CIMIS Web site.

The daily (24-hour) PM equation was used in the SIMETAW, CUP and BIS programs.

Compared the University of Missouris method of calculating reference ET to the standardized Penman-Monteith method. Results show that they were close, but tended to stray off under higher wind conditions. Plans are underway to convert MU to the standard Penman-Monteith protocol in late 2003.

AgriMet program is exploring the possibility of contracting to implement new standardized reference ET equation.

Evapotranspiraion of cotton was measured using weighing lysimeters in 2001-2002 with precision weighing lysimeters under full-, deficit-irrigation, and dryland water regimes as well as a previous season (2000) at Bushland. Cotton water response was measured in 2001 in the smaller lysimeters under an automated rain shelter for three soils  Pullman clay loam (Bushland, TX), Amarillo sandy loam (Big Spring, TX), and Ulysses silt loam (Garden City, KS) in the Soil-Plant-Environment-Research (SPER) facility. Fourteen new cores of Vingo sandy loam from Dalhart, TX were collected to replace 12 of the 24 Ulysses cores to provide four soils with the Vingo soil having a low-water holding capacity. The FAO-56 ET model has been continued to be tested for sorghum and cotton at Bushland.

Obj. 4. Identification, documentation, and verification of crop coefficients used in irrigation scheduling, including method by which coefficients are moved forward in time (accumulated heat units, % crop cover, time, etc.)

In California, a modification the FAO linear method to estimate crop coefficients is being used to determine crop coefficient curves.

Rather than using the number of days during the 4 growth periods (initial, rapid, midseason and late-season), the Kc models use a percentage of the season to identify the end points of each growth period. This has eliminated the biggest problem, which is to help growers identify the onset of senescence. It also simplifies calculations since the grower only needs to input the beginning and ending dates of the season. All other dates are calculated using the percentages.

Conducted research on corn (3Relative Maturities) with 2 planting dates, soybeans (row-planted & drilled) with 2 planting dates, and cotton (row-planted & drilled) with 2 planting dates to develop crop coefficients for ETo.

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. The crop coefficients are based on days past emergence (DPE). The crop coefficients for potatoes were checked as part of other ongoing research and generally are correct.

AgriMet uses a set of crop coefficients originally developed by the USDA ARS in Kimberly, Idaho. The ET procedure uses emergence dates provided by local contacts, such as ag consultants or extension agents. Other required inputs include full cover and terminate dates. These dates are normally derived from a table of historical relationships with emergence dates. This local contact method is very time consuming and potentially inconsistent. AgriMet crop curves are available on the internet at http://mac1.pn.usbr.gov/agrimet/cropcurves/About_Crop_Curves.html.

Allen, R,G., Walter, I.A., Elliott, R., Itenfiisu, D., Brown, P., Jensen, M.E., Mecham, B., Howell, T.A., Snyder, R., Eching, S., Spofford, T., Hattendorf, M., Martin, D., Cuenca, R.H., and Wright, J.L. 2003. The ASCE standardized reference evapotranspiration equation. pp. 593-602. In A.J. Clemens and S.S. Anderson (eds.), Proc. 2nd Intl. Conf. on Irrig. and Drain., May 12-15, 2003, Phoenix, AZ, Water for a Sustainable World  Limited Supplies and Expanding Demand. U.S. Committee on Irrigation and Drainage, Denver, CO.

Auvermann, B., T. Marek and D. Parker. 2002. Assessing the Water Demand for Sprinkler Dust Control on High Plains Feedyard. 2002 North Plains Research Field Ag Day. TAES-AREC 02-33. 1-2 pp.

Colaizzi, Paul D.; Edward M. Barnes; Thomas R. Clarke; Christopher Y. Choi; Peter M. Waller; J. Haberland; and Michael Kostrzewski. 2003. Water Stress Detection under High Frequency Sprinkler Irrigation with Water Deficit Index. Journal of Irrigation and Drainage Engineering, Vol. 129, No. 1, pp. 36-43.

Colaizzi, Paul D., Edward M. Barnes; Thomas R. Clarke; Christopher Y. Choi, and Peter M. Waller. 2003. Estimating Soil Moisture under Low Frequency Surface Irrigation Using Crop Water Stress Index. Journal of Irrigation and Drainage Engineering, Vol.129, No., pp. 27-35. February 1, 2003.

Evett, S. R. 2002. Water use in crop production. Vadose Zone J. 1:204-206.

Evett, S.R., N. Ibragimov, B. Kamilov, Y. Esanbekov, M. Sarimsakov, J. Shadmanov, R. Mirhashimov, R. Musaev, T. Radjabov, and B. Muhammadiev. 2002. Soil moisture neutron probe calibration and use in five soils of Uzbekistan. 7th World Congress of Soil Science, August 14-21, 2002, Bangkok, Thailand, Transactions, pp. 839-1-839-10. (CD-ROM).

Evett, Steven, Jean-Paul Laurent, Peter Cepuder, and Clifford Hignett. 2002. Neutron Scattering, Capacitance, and Tdr Soil Water Content Measurements Compared on Four Continents. 7th World Congress of Soil Science, August 14-21, 2002, Bangkok, Thailand, Transactions, pp. 10211-102110. (CD-ROM).

Evett, S.R., J.A. Tolk, and T.A. Howell. 2003. Sensors for Soil Profile Water Content Measurement: Accuracy, Axial Response and Temperature Dependence. Geophysical Research Abstracts, Vol. 5, 09944.

Evett, S.R., T.A. Howell, A.D. Schneider, D.F. Wanjura, and D.R. Upchurch. 2002. Automatic drip irrigation control regulates water use efficiency. International Water and Irrigation, Vol. 22, No. 2, pp. 32-37.

Evett, S.R., B.B. Ruthardt, S.T. Kottkamp, T.A. Howell, A.D. Schneider, and J.A. Tolk. 2002. Accuracy and precision of soil water measurements by neutron, capacitance, and TDR methods. 17th World Congress of Soil Science, August 14-21, 2002, Bangkok, Thailand, Transactions, pp. 318-1-318-8. (CD-ROM).

Henggeler, J. 2002. Irrigation Scheduling Works. Integrated Pest and Crop Management. University of MO. 12:6:24.

Henggeler, J. 2002. Woodruff Irrigation Chart does good job on corn. MidAmerica Farmer/Grower. Jan 11.

Henggeler, J. 2002. Adequate moisture needed during final irrigation. MidAmerica Farmer/Grower. Aug. 2.

Henggeler, J. 2002. Programs Available for Irrigation Scheduling. Proc. of The Improving Irrigation Efficiency in Agriculture Conf. Las Cruces, NM, Mar. 20-21.

Henggeler, J. 2002. Software Programs Currently Available for Irrigation Scheduling. Proc. of Irrigation Association. New Orleans, Oct. 24-26.

Hignett, C., and S.R. Evett. 2002. Thermalization. Section 3.1.3.10 In Jacob H. Dane and G. Clarke Topp (eds.) Methods of Soil Analysis. Part 4 - Physical Methods. pp. 501-521.

Howell, T.A. 2002. Irrigation efficiency. pp. 736-741. In R. Lal (ed.), Encyclopedia of Soil Science. Marcel Dekker, Inc., New York, NY.

Howell, T.A. 2002. Irrigation system efficiencies. In. Proc. of the Central Plains Irrigation Short Course & Exposition, Colorado State University, Kansas State University, University of Nebraska, and Central Plains Irrigation Assn., Lamar, CO. pp. 80-92.

Howell, T.A., S.R. Evett, J.A. Tolk, and A.D. Schneider. 2002. Evapotranspiration of full-, deficit-irrigated and dryland cotton on the northern Texas High Plains. pp. 321-339. In C.M Burt and S.S. Anderson (eds.) Proceedings 2002 USCID/EWRI Conference. Energy, Climate, Environment and Water - Issues and Opportunities for Irrigation and Drainage. U.S. Committee on Irrigation and Drainage, Denver, CO.

Kamilov, B., N. Ibragimov, S. Evett, and L. Heng. 2002. Use of neutron probe for investigations of winter wheat irrigation scheduling in automorphic and semi-hydromorphic soils of Uzbekistan. Accepted for publication In Proc. International Workshop on Conservation Agriculture for Sustainable Wheat Production in Rotation with Cotton in Limited Water Resource Areas, October 13-18, 2002, Tashkent, Uzbekistan.

Kamilov, Bakhtiyor; Ibragimov, Nazirbay; Esanbekov, Yusupbek; Evett, Steven; and Heng, Lee. 2002. Irrigation Scheduling Study of Drip Irrigated Cotton by use of Soil Moisture Neutron Probe. In Proceedings of the UNCGRI/IAEA National Workshop "Optimization of water and fertilizer use for major crops of cotton rotation," December 24-25, 2002, Tashkent, Uzbekistan.

Kamilov, Bakhtiyor; Ibragimov, Nazirbay; Esanbekov, Yusupbek; Evett, Steven; and Heng, Lee. 2003. Drip Irrigated Cotton: Irrigation Scheduling Study by Use of Soil Moisture Neutron Probe. International Water and Irrigation. Vol. 23. No. 1. pp. 38-41.

Kostrzewski, M., Waller, P., Guertin, P., Haberland, J., Colaizzi, P., Barnes, E.,Thompson, T., Clarke, T., Riley, E., Choi, C. 2003. Ground-based remote sensing of water and nitrogen stress. Transactions of the ASAE. Vol. 46(1): 29-38.

Marek, T. 2002. The 2002 Drought? 2002 North Plains Research Field Ag Day. TAES-AREC 02-33. 11-12 pp.

Marek, T. 2002. The Texas A&M Statewide EvapoTranspiration Network. 2002 North Plains Research Field Ag Day. TAES-AREC 02-33. p. 13.

Thompson, A.L., J.C. Henggeler, D.L Bockhold, and K.A. Sudduth. 2002. Comparison of Eight Irrigation Scheduling Tools on Soybean and Cotton. International Water and Irrigation. 22:3:24-30.