Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 30, 2007
Publication Date: May 1, 2007
Citation: Sullivan, D.G., Truman, C.C., Schomberg, H.H., Endale, D.M., Franklin, D.H. 2007. Potential impact of conservation tillage on conserving water resources in Georgia. Journal of Soil and Water Conservation. 62:145-152. Interpretive Summary: Increasing demand and diminishing water resources have resulted in tri-state water resource negotiations. As a result, Georgia has required that a comprehensive water plan for the state be established by 2007. Thus, accurate estimates of water use and the impact of conservation programs are necessary to ensure that agricultural water needs are met. A major goal of this study was to evaluate the impact that conservation tillage has on conserving water resources. This was accomplished by integrating measurable changes in infiltration associated with conservation tillage, with county level crop, tillage and soil data. We estimate that conservation tillage currently reduces statewide irrigated water requirements by as much as 12 % compared to water use under 0 % conservation tillage. Using a geographical information system, intensively row-cropped counties having a conservation tillage adoption rate < 40 % were identified. Increasing the adoption rate of conservation tillage in these counties to 40 % increased potential water savings statewide by an additional 10% (136, 231ML).
Technical Abstract: Reduced tillage and residue management increases infiltration, soil water content, and plant available water estimates, while at the same time decreases runoff and sedimentation. Yet, there is a general lack of knowledge and appreciation regarding the impact conservation tillage has on sustainable water resources. The objective of this study was to estimate potential water savings as a result of conservation tillage adoption in Georgia. Total acreages by crop (cotton, corn, and peanut) and tillage (conventional and conservation) were obtained via the Conservation Technology Information Center (CTIC) for the 2004 growing season. Rainfall simulation studies conducted over row-cropped lands in conventional and conservation tillage were obtained for soils in the Coastal Plain and Piedmont physiographies. Data were integrated within a geographical information system (GIS). We estimate that conservation tillage currently reduces statewide irrigated water requirements by as much as 12 % compared to water use under 0 % conservation tillage. Increasing conservation tillage to 40 % in intensively row-cropped counties where conservation tillage adoption rates were less than the national average (41%) is estimated to provide an additional 10 % water savings statewide.