Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/29/2008
Publication Date: 6/29/2008
Citation: Jaynes, D.B., Thorp, K.R. 2008. Potential Water Quality Impact of Drainage Water Management in the Midwest Cornbelt [abstract]. American Society for Agricultural and Biological Engineers. Paper No. 08-4566.
Technical Abstract: Drainage water management (DWM) is being investigated as a possible management option for reducing nitrate leaching to surface waters from the artificially drained Midwest cornbelt. This work builds on earlier modeling studies where a calibrated Root Zone Water Quality Model was used to predict the effect of DWM on N losses across the cornbelt. Estimates of drained cropland were made using the 1992 National Land Cover Database and STATSGO soils information. Information from the 2002 NASS crop database was used to estimate how much of this drained cropland was planted to continuous corn and corn-soybean rotations. Estimates of the total load of N that would be reduced by implimentation of DWM was then made by combining the RZWQM modeling results with the estimates of drained corn and corn-soybean lands within the cornbelt. This reduced mass of N was then compared against the N load reduction required to reduce hypoxia in the northern Gulf of Mexico to the 5,000 square kilometer limit recommended by the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force. Findings show that while DWM can potentially reduce N loadings to surface waters by substantial amounts, this reduction represents less than 10% of the required reduction for Gulf hypoxia.