Progress 08/01/09 to 07/31/10
Outputs
OUTPUTS: Primary experimental activities were field studies examining the agronomic relationship of crop yield and water supply as affected by irrigation technology, tillage and residue management, nitrogen management and plant density for use in evaluating limited-irrigation strategies. In the agricultural economics objective, the primary activity was determination of economic returns and risk levels under alternative deficit irrigation scenarios. Project participants made presentations at national, regional and state conferences, primarily at the annual meetings of the American Society of Agricultural and Biological Engineers, the Irrigation Association, and at the Central Plains Irrigation Conferences. Other extension presentations were made in Kansas venues throughout the life of the project. Each of these presentations was accompanied by a written paper. Updates and revisions were made to computer software that compares center pivot sprinkler irrigation and subsurface drip irrigation, and the software was made available through the internet for free downloading. Updates were made to Crop Water Allocator (CWA), software that examines alternative irrigated crop rotations. Crop Yield Predictor, a software program that predicts grain yields and net economic returns for each irrigation schedule alternative, was developed. Training programs were conducted in western Kansas for both CWA and CWP and also KanSched, a day-to-day weather-based irrigation scheduling program. PARTICIPANTS: F. R. Lamm, D. H. Rogers, L. R. Stone, N. L. Klocke, B. Golden serve as principal investigators on the project. Technical support staffs exist at both the Northwest and Southwest Research-Extension Centers to help with the field research projects. The Kansas Corn Commission, the National Sunflower Association and the USDA-ARS have provided funding through grants and cooperative agreements. Partnerships through collaborations are with the USDA-ARS staff at Bushland, Texas. TARGET AUDIENCES: The target audiences are crop producers, primarily within the region, but extending nationally; crop consultants; USDA-NRCS staff; water managers and planners, primarily within Kansas; and the international scientific community. Primary dissemination efforts will be through field days and workshops such as the Central Plains Irrigation Conference and through publications and internet websites. PROJECT MODIFICATIONS: No changes are relevant to this project at this time.
Impacts
Differences in soil water evaporation between bare soil and residue treatments were 0.50 to 0.75 mm/day which, for a seasonal basis, might be 55 to 58 mm. The impact of this change in knowledge is that producers might be able to obtain as much as 2.7 Mg/ha additional corn yield. Irrigators should plan for irrigated corn water use during the last 30- and 15-day periods that may average nearly 125 and 50 mm, respectively, to avoid yield reductions. The allowable soil water depletion during the period after corn silking should be limited to 45% of the available soil water for a 2.4-m profile on the deep silt loam soils of this climatic region to avoid yield reductions. KanSched is an irrigation scheduling software program developed to allow irrigation managers to use ET or crop water use information to schedule irrigation applications. ET information is available from a number of weather stations throughout Kansas. Tests using KanSched with a number of typical weather scenarios suitable for western Kansas indicated that gross irrigation savings of 25 to 100 mm per year are realistic when weather-based irrigation scheduling is practiced. In addition to the conserved water resource, energy savings of $25 to $100/ha are possible. Economic comparison of center pivot sprinklers and subsurface drip irrigation (SDI) indicated that SDI can be more profitable than sprinklers with good corn yields and current crop prices, provided the SDI system can last at least 20 years. Results from utilization of Crop Water Allocator (CWA) and Crop Yield Predictor (CYP) are being used by the USDA Risk Management Agency to develop policies for implementation of crop insurance programs that apply to deficit irrigation management.
Publications
- Blanco-Canqui, H, Klocke, N.L., Schlegel, A.L., Stone, L.R., and Rice, C.W. 2010. Impacts of deficit irrigation on carbon sequestration and physical properties in no-till soils. Soil Sci. Soc. Amer. J. 74(4):1301-1309.
- Coyne, P. I., Aiken, R.M., Maas, S.J., and Lamm, F.R. 2009. Evaluating YieldTracker forecasts for maize in western Kansas. Agron J. 101:671-680.
- Klocke, N.L., Stone, L.R., Briggeman, S., and Bolton, D.A. 2010. Scheduling deficit-irrigation crop yield predictor. J. Appl. Engr. in Agric. 26(3):413-418.
- Klocke, N.L., Currie, R.S., Stone, L.R., and Bolton, D.A. 2010. Planning for deficit irrigation. J. Appl. Engr. in Agric. 26(3):405-412.
- Rogers, D.H., Shaw, L.K., Pragada, S.R., and Alam, M. 2010. Evaluation of pressure regulators from center pivot nozzle packages. In: Proc. 22nd Annual Central Plains Irrigation Conference, Kearney, NE., Feb. 24-25, 2010. Available from CPIA, 760 N.Thompson, Colby, KS. pp. 58-67.
- Stone, L.R. and Schlegel. A.J. 2010. Tillage and crop rotation phase effects on soil physical properties in the west-central Great Plains. Agron. J. 102:483-491.
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