Investigating automatic irrigation scheduling and quantifying water use efficiency for limited and fully irrigated grain sorghum using LEPA irrigation

Project Details

  • Susan O'Shaughnessy
  • USDA-ARS Bushland
  • $13,500
  • Year: 2009


Project Summary

This proposal is submitted by a group of investigators who amongst them have high levels of expertise and experience in areas of irrigation engineering, soil science, automatic irrigation scheduling, crop water use measurement and estimation, agronomy, and sensor development. This proposal also represents collaboration between two entities, USDA-ARS and Texas AgriLife Extension Services for a two year research project. Progress from the study will be published in the Bushland USDA-ARS bi-annual news letter (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 an important forage and grain crop and is widely used as agricultural feedstock for ethanol production. In the Northern High Plains district of Texas, 40% of grain sorghum is irrigated, resulting in yields double to those from dryland farming (Colaizzi et al., 2008). Improving crop productivity without significantly impacting the existing water supply is becoming a major focus of consideration for producers to either maintain or improve their profitability. This research project will investigate automatic irrigation scheduling based on a temperature stress index. Crop canopy temperature measurements will be made from wireless sensors mounted on a six-span center pivot arm. Yield responses will be analyzed across fully randomized plots (four manual irrigation treatments- 80%, 55%, 30%, and 0% of evapotranspiration (ET) (calculated from Penman Monteith Equation and retrieved from the Texas High Plains ET network) and their automatic analogs and three replications, blocked by control type (manual or automatic) and analyzed using Proc Mixed statistical models.

In cooperation with Texas AgriLife Extension Service, our field experiment will be incorporated as an onsite visit during a sorghum field day. Possible topics to be included in the field day include: the impacts of limited irrigation on sorghum development and productivity, irrigation levels and water use efficiency, optimal thermal stress indexes for irrigation scheduling, and the impact of irrigation technology on water conservation and profitability.