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Journal of Environmental Hydrology
ISSN 1058-3912 |
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Electronic Journal of the International Association for
Environmental Hydrology
JEH Volume 14 (2006), Paper 13 Posted September 22, 2006 MODELING ALTERNATIVE AGRICULTURAL MANAGEMENT PRACTICES FOR HIGH ISLAND CREEK WATERSHED IN SOUTH-CENTRAL MINNESOTA
Prasanna H. Gowda1 2Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN ABSTRACT Nonpoint source pollution from row crop land is a widespread problem in North America. Concerns include sediment, nitrate and phosphorus loadings to water bodies from row cropped lands. In this study, a spatial-process based water quality model was calibrated (2001-2002) for flow, sediment, nitrate and phosphorus losses from the High Island Creek, a 3856 ha agricultural watershed located in south-central Minnesota. The calibrated model was used to evaluate alternative tillage and fertilizer management practices such as adoption of conservation tillage practices, rate, timing and method of N- and P-fertilizer applications, and method of manure application. Statistical comparison of calibration results with observed data indicated excellent agreement with r2 of 0.95, 0.96, 0.87, and 0.97 for flow, sediment, nitrate and phosphorus losses, respectively. The model simulated a 37.5% reduction in annual sediment losses can be achieved by adopting conservation tillage on all row cropped land in the watershed. Reductions in annual nitrate losses can be achieved by switching the timing of application from fall to spring and by reducing the rate of nitrogen fertilizer application. A 41% reduction in annual nitrate losses can be achieved if all farmers adopt injection as a method for animal manure application. Reference: Gowda, P.H. and D.J. Mulla. 2006. Modeling alternative agricultural management practices for High Island Creek watershed in south-central Minnesota. Journal of Environmental Hydrology, Vol. 14, Paper 13. CONTACT: Prasanna H. Gowda Agricultural Engineer CPRL-USDA-ARS P.O. Drawer 10 Bushland, TX 79012-0010 E-mail: pgowda@cprl.ars.usda.gov |
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