Project Number: 5402-61660-006-15
Project Type: Specific Cooperative Agreement

Start Date: Sep 15, 2012
End Date: Sep 14, 2017

Objective:
The longer term goals of this cooperative research project between USDA-ARS and Colorado State University are to: 1) further improve understanding and quantification of the response of crops to water stress at different growth stages, temperature-CO2-water-N interactions, and evapotranspiration (ET) for enhancement of crop and rangeland system models; 2) use the enhanced system models to develop management and cultivar adaptations to limited water and warming climate to sustain food production and maintain environmental quality in the Great Plains; 3) develop simpler decision tools to guide management at the farm and ranch levels; such as a water optimizer for selecting the crops, acreage, and level of irrigation, an irrigation scheduler, and a drought calculator for rangelands; and 4) apply the enhanced system models in precision management of water and nutrients. Specific objectives (Statement of Work) for the funds being provided in this amendment are to: 1) further improve quantification of crop water stress responses in corn, wheat, and beans, including analysis of energy balance data for corn at different levels of ET-based irrigation; 2) explore optimum intervals of water applications to meet crop water demand at 100%, 75%, and 50% levels of potential crop ET for corn; and 3) advise and assist in simulating water-temperature-CO2-N interactions and management adaptations to climate change for rangelands in the Central Great Plains.

Approach:
The CSU and ASRU scientists will work closely together in the CSU field research studies and collaborate with ARS and university colleagues conducting field studies in the Great Plains to accomplish the above objectives. The different steps involved are: 1) analyze appropriate datasets for responses to different levels of water and water-N-temperature-CO2 interactions and quantify them; 2) incorporate the newly quantified interactions into the ASRU cropping system model, RZWQM2, and the ASRU rangeland model GPFARM-Range; 3) test and validate these models against the data; 4) use validated models to explore the selected management and cultivar adaptations over longer durations of climate; and 5) develop simpler tools to guide management.