S1018 Regional Committee on Irrigation Management for Humid and Sub-humid Regions Annual Report

Authors: Sassenrath, Gretchen; Fisher, Daniel; Thomson, Steven

Submitted to: National Information Management and Support System
Publication Type: Proceedings
Publication Acceptance Date: 9/15/2008
Publication Date: 9/15/2008
Citation: Sassenrath, G.F., Fisher, D.K., Thomson, S.J. 2008. S1018 Regional Committee on Irrigation Management for Humid and Sub-humid Regions Annual Report. National Information Management and Support System. http://nimss.umd.edu/homepages/home.cfm?trackID=4575

Interpretive Summary: Unlike other areas of the South, Mississippi enjoys plentiful ground water resources and rainfall in excess of 40” per year. The challenge for Mississippi is to manage water resources appropriately, and provide sufficient water for crop production during droughty periods that occur during the growing season. Uncertainty of amount and timing of rainfall makes irrigation scheduling a particular challenge, as a high rainfall event immediately following an irrigation can result in water logging of the soils and impede crop growth. Yields and profits from non-irrigated crops are typically lower than for irrigated fields, resulting in greater use of ground water in the Mississippi Delta. The increased pumping has resulted in an average decline from the alluvial aquifer of 300,000 acre feet of water per year for the past 10 years. Farmers are under increasing pressure to reduce the impact of management practices on soil and water resources. Conservation systems with high levels of cover crop residue have been shown to reduce the need for supplemental irrigation on sandy soils, in part due to increased percolation of water into the soil profile. However, the need to increase surface drainage in the early spring in the Delta may limit the use of cover crops in this region, further exacerbating efforts to increase the use of conservation tillage practices and limiting potential conservation incentive payments to farmers. The consequences of production practices on conservation of soil and water resources are also unknown. The research described here addresses concerns of irrigation scheduling and development of crop production practices for optimal management of soil and water resources for the environmental conditions of the region.

Technical Abstract: The overall goal of our research is the development of economically viable, environmentally sound production systems for the Mid-South. Because of the growing importance of water management to crop production in the Lower Mississippi Alluvial Flood Plain, particular emphasis is placed on addressing issues of crop water use, and irrigation timing and amounts. The Regional Committee S1018 Irrigation in Humid and Sub-Humid regions is focused to address problems and challenges of water management in agricultural systems in humid environments. In collaboration with university, Federal, and Extension scientists on the committee, ARS scientists at Stoneville, MS are developing irrigation systems and application guidelines and alternative crop production practices to improve water use and enhance crop productivity in the region. Because the implementation of many production practices, such as crop rotations and conservation tillage, may not be apparent for 4 to 5 years, these studies are of necessity long term. The results will be incorporated into decision support information and guidelines for optimal crop production for delivery to producers.