1a. Objectives (from AD-416)
The objective of this project is to facilitate coordinated research on soil and crop management for efficient water use, through collaborative efforts with Texas Tech University students and faculty.
1b. Approach (from AD-416)
Conduct fundamental and applied research on the causes and consequences of wind-induced erosion, and the interactions of plants with the soil and aerial environments; to develop wind erosion mitigation strategies and water management strategies that alleviate, delay, or moderate the impact of drought and thermal stress on crop production; to develop both short- and long-term strategies that conserve irrigation water by increasing the use of rainfall.
3. Progress Report
This agreement provides stipends to support graduate students expanding the Unit's research capacity. The research of five graduate students at TTU was supported and a brief description of each follows. 1) One study evaluated the economic impact of seasonal climate forecast information, especially pertaining to winter rainfall, for wheat and cattle producers of the USA Great Plains region. The objective was to investigate their decision-making process and to evaluate the economic impact of seasonal forecast information on these decisions. 2) The feasibility of using variable-rate seeding in dryland cotton production in the Texas High Plains (THP) was investigated. Results showed that given the high cost of seed-cotton, the practice of variable-rate planting can increase profitability; however, the high cost of the seed-planter prevents the wide adoption of this practice. 3) The application of the model Hydrus-3D, which describes the transport of water in the soil in three dimensions, was applied to study water movement using a buried drip irrigation system in cotton. Crop irrigation with subsurface drip is increasing in the THP, but information on drip-tape positioning and irrigation strategies is needed to optimize rainwater harvesting. The objective was to validate the model and then use the calibrated model to evaluate irrigation frequency and timing strategies for cotton. Results showed that the model calculated soil water content within 3% of measured values, indicating that the model can evaluate irrigation strategies. 4) Another study determined the effects of crop management and interactions on dust emission. For this purpose a portable wind tunnel was designed and built, and evaluated on three soils. Dust emissions from the tunnel were compared to those obtained using a dust generator. Results indicated no trend between the two methods. 5) It is estimated that about 50% of rain in the THP is lost due to runoff, and one way to decrease this loss is to plant crops in a circular pattern in contrast with linear rows. The idea is that the circular rows provide a physical barrier to increase rain detention and thus increases infiltration. This hypothesis was tested using the Precision Agricultural Landscape Modeling System (PALMS) to simulate soil water for the environmental conditions of the THP. Measurements of soil water were collected throughout the growing seasons at several sites to compare values and the spatial distribution of soil water with PALMS calculated values. Soil water measurements were consistently within 5% of simulated values. Improvements in PALMS model soil water calculations indicate that the model is useful to assess long-term implications of management practices designed to conserve irrigation water and maximize the profitability of dryland cropping systems. ADODR is in regular contact with cooperator via e-mail, phone, and face-to-face contacts.