Posted on Dec 01, 2010
This proposal is submitted as a continuing research project for automatic irrigation scheduling of deficit irrigated grain sorghum and its impact on water use efficiency. Investigators collaborating on this project have high levels of expertise and experience in areas of irrigation engineering, soil science, plant physiology, automatic irrigation scheduling, crop water use measurement and estimation, agronomy, and sensor development. This proposal also represents collaboration between USDA-ARS and Texas AgriLife Extension Service for a multi-year research project. Progress from the study will be published in the Bushland USDA-ARS semi-annual newsletter (the “Wetting Front” product of the Soil & Water Management Research Unit), and a refereed journal. Agronomic progress and results will also be disseminated by Texas AgriLife Extension Service for outreach with local producers.
Sorghum is a highly adaptable forage and grain crop and is an important agricultural feedstock for dairies and ethanol production. In the Northern High Plains district of Texas, 40% of grain sorghum is irrigated, resulting in yields double those from dryland farming (Colaizzi et al., 2008). Improving crop productivity without significantly impacting the existing water supply and quality of the yield is becoming a major focus of consideration for producers to either maintain or improve their profitability. This research project will continue to investigate automatic irrigation scheduling based on two different types of thermal stress indices and two different varieties of grain sorghum using center pivot systems and LEPA irrigation. Crop canopy temperature measurements and microclimatological data will be made from sensors located on the pivot and in the field. Main effects of deficit irrigation treatments and manual and automatic methods will be analyzed against sorghum yields.
In cooperation with Texas AgriLife Extension Service, whenever possible, our field experiment will be incorporated as an onsite visit during a sorghum field day. Results will be incorporated into sorghum management Powerpoint presentations at local and regional Extension programs. Possible topics to be included in the field day include: the impacts of limited irrigation on sorghum development and yield, irrigation levels and water use efficiency, optimal thermal stress indexes for irrigation scheduling, and the benefits of irrigation technology on water conservation and profitability.