Project Number: 6208-13000-007-00
Project Type: Appropriated

Start Date: Dec 22, 2011
End Date: Dec 21, 2016

Objective:
1: Evaluate a new technique using mid-infrared spectroscopy to characterize soil organic matter (SOM) properties and its effects on soil water holding capacity and to characterize erodibility of agricultural landscapes. 1A: Identify management-induced changes in SOM characteristics affecting soil water availability in sandy soils using a new technique for characterization of chemical composition of SOM, Fourier-transform Mid-infrared Spectroscopy. 1B: Quantify the combined effects of wind and water erosion on subsequent erodibility of agricultural landscapes. Objective 2: Compare and contrast water use efficiency among deficit irrigation strategies, and develop decision support tools to determine optimal irrigation and crop rotation strategies. 2A: Compare three types of deficit irrigation scheduling methods (Stress Time, Stress Degree Hours, and Crop Water Stress Index) in terms of final irrigation amounts, irrigation timing and cotton crop water use efficiency. 2B: Develop decision support tools to determine optimal irrigation and crop rotation strategies. 2C: Quantify the effects of wind speed, tillage type, and surface irradiance on the surface evaporation component of water use efficiency. 3: Conduct climate analysis and integrate large-scale hydrology models with process level-plant growth models in order to simulate optimum water and energy use for crop production on the Southern High Plains. 3A: Develop informational web sites to inform producers of the Ogallala region and other agricultural regions of recent climate trends. 3B: Develop and test a simulation model that will calculate landscape-scale mass and energy balance in pivot irrigated cotton systems at a detailed spatial and temporal resolution. 4: Monitor and model water depth in temporary playa wetlands for potential agronomic uses and also to determine the potential for aquifer recharge. 4A: Design, fabricate, deploy, evaluate, and maintain climatologic and hydrologic instrumentation in playa wetlands. 4B: Determine effects of proximate land use on playa basin hydrologic characteristics.

Approach:
Our goal is to develop and evaluate models and methods that use limited water resources efficiently to maintain economically viable deficit irrigated and dryland agricultural production systems. New approaches will identify land management effects on soil organic matter properties and resulting effects on soil water holding capacity. The combined effects of both wind and water on subsequent erodibility of agricultural landscapes will be quantified. Effects of irrigation timing and total application rate on water use efficiency will be compared among different deficit irrigation scheduling methods. New research will explore the interactive effects of tillage and environmental variables on the surface evaporation component of water use efficiency. Decision support tools will be developed to determine optimal irrigation and crop rotation strategies while other studies will develop simulation models of landscape-scale mass and energy balances at detailed spatial and temporal resolutions. These modeling studies will be used to simulate optimum water and energy use for crop production on the Southern High Plains. Climate analyses will be conducted to develop informational web sites to inform agricultural producers of recent climate trends and potential impacts on future agricultural productivity. Finally, temporary playa wet lands will be evaluated to determine the potential for aquifer recharge as well as for future agronomic uses. This multifaceted research program will provide the knowledge base for optimizing the use of scarce water resources in arid and semi-arid regions where ground water resources are being depleted.