Submitted to: Soil and Water Conservation Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 5, 2006
Publication Date: October 13, 2006
Citation: Hubbard, R.K., Bosch, D.D., Strickland, T.C., Truman, C.C., Potter, T.L. 2006. Comparison of Conservation and Conventional Tillage Effects on Water Quality in a Coastal Plain Soil [abstract]. Soil and Water Conservation Society Proceedings, October 11-13, 2006, Kansas City, Missouri. Technical Abstract: A study was conducted from 2000-2004 on a Coastal Plain soil to determine the effect of tillage method (strip versus conventional) on surface runoff and shallow groundwater quality. Six 0.2 ha plots (three strip till and three conventional till) on a Tifton loamy sand (fine-loamy, plinthic, Kandiudult) were surrounded by 0.6 m berms and instrumented for collection of surface runoff. The plots were tile drained to capture shallow subsurface drainage at 1.2 m from each of the tillage systems. The cropping system included cotton and peanuts on a two year rotation. Surface runoff and shallow groundwater samples were collected and analyzed for NO3-N, NH4-N, and Cl concentrations. Results from the study showed differences in the water balance and total nutrient mass lost from the systems related to tillage system. The average annual area weighted surface runoff was 304 mm yr-1 (29% of the annual rainfall) for the conventionally tilled plots and 168 mm yr-1 (16% of the annual rainfall) from the strip tilled plots. Subsurface water losses from the conventionally tilled plots were approximately 9% of annual rainfall while they were 16% of the annual rainfall from the strip tilled plots. Solute concentrations in runoff and shallow groundwater did not significantly differ between tillage systems. Total mass losses from the plots hence were a function of the water balance, with significantly greater losses occurring by surface runoff from the conventional tillage, and by subsurface flow from the strip tillage.