CONSERVATION EFFECTS ASSESSMENT IN THE SOUTH GEORGIA LITTLE RIVER
Location: Southeast Watershed Research
Title: Seasonal Hydrologic Impacts of Conservation Tillage for a Coastal Plain Soil
Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: December 3, 2007
Publication Date: June 29, 2007
Citation: Bosch, D.D., Potter, T.L., Truman, C.C., Strickland, T.C. 2007. Seasonal Hydrologic Impacts of Conservation Tillage for a Coastal Plain Soil. ASABE Annual International Meeting 06/29-07/02/2008. Providence, RI. p. 1-13.
Interpretive Summary: Strip till, a practice of planting into a narrowly tilled strip, is a growing practice among many Coastal Plain cotton growers. Strip tillage, and other conservation tillage systems, can lead to increased infiltration, reduced surface runoff, and reduced transport of sediment and agrichemicals. A research site comparing the rainfall-runoff characteristics of conventional till and strip till systems was studied for nine years. Annual water gains in the strip till system obtained through enhanced infiltration and reduced surface runoff were offset by increased subsurface losses. Subsurface losses from the strip till system were particularly high during spring months. Strip till had the greatest benefit in terms of increased water gains during years with the least annual precipitation, indicating that strip till can potentially offset the adverse impacts of drought during the growing season. Surface and subsurface losses from both tillage systems are the greatest during March, indicating a higher potential for agrichemical losses during this month.
Conservation tillage has proven to be an effective water management tool for cotton production on sandy, drought-prone soils throughout the Coastal Plain. Conservation tillage increases crop residue at the surface, leading to reduced evaporation, reduced raindrop impact, increased infiltration, reduced surface runoff, and reduced transport of sediment and agrichemicals at the soil surface. Prior research indicated that the benefits of conservation tillage are the greatest during the period from June through August. This research examines nine years of rainfall-runoff data from a paired conservation till / strip till research site. Differences between runoff characteristics from the paired plots are examined and quantified for both a cotton and a peanut crop. In addition, improved seasonal relationships for estimating runoff from the plots are presented.