Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2007
Publication Date: 11/1/2007
Citation: Rowland, D., Piccinni, G., Howell, T.A., Ko, J., Marek, T.H., Faircloth, W.H., Payton, P.R., Tissue, D.T. 2007. Irrigation in water restricted regions: Managing water use efficiency with limited available water [abstract]. ASA-CSSA-SSSA Annual Meeting, November 4-8, 2007, New Orleans, Louisiana. 2007 CDROM. Interpretive Summary:
Technical Abstract: Political and social pressures to increase water-use efficiency in agriculture from plant to regional scales are reaching critical levels. A region where these pressures have been extremely acute is most semi-arid parts of Texas where reliable crop production is possible only through irrigation. Regulations restricting water use from underground aquifers, increased municipal/industrial competition for water coupled with drought during crop growing seasons continue to place a large strain on aquifers and water resources in the Edwards and Ogallala aquifer regions in Texas. Irrigation in these two intensively cropped areas is often mismanaged. A better understanding of how much and when to apply water, whether based on ETc (crop evapotranspiration) values derived from climatic models, direct crop water use measurement, or precise soil water or plant water status monitoring, can be the basis for improved irrigation management and optimum application rates. One research approach targeted at increasing water-use efficiency is based on the understanding that the plant available water needed to sustain transpiration and avoid water stress is not a fixed quantity but depends on the atmospheric demand. Thus, the possibility of managing water restrictions depends on the average atmospheric demand for the period between irrigations. Another approach has aimed at developing irrigation schemes that maximize crop production in this environment while reducing overall water consumption through the use of early season deficit irrigation and increased crop tolerance to late season drought. Furthermore, we are conducting studies to develop more accurate and region-specific crop coefficients, improving the precision of weather-based irrigation scheduling for economically-important crops in Texas. These results provide applicable solutions to growers that increase water-use efficiency while maintaining economic viability under water scarcity. The environmental and economic impact of this research is measured in terms of water savings and net returns to farmers.