|Mulla, David - UNIVERSITY OF MINNESOTA|
Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 10, 2006
Publication Date: July 10, 2006
Citation: Gowda, P., Mulla, D.J. 2006. Evaluating alternative agricultural management practices for a minor agricultural watershed using the ADAPT method. In: Proceedings of the ASABE Annual International Meeting, July 9-12, 2006, Portland, Oregon. 2006 CDROM. Paper No. 062044. Technical Abstract: 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 r**2 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. The model predicted a 41% reduction in annual nitrate losses can be achieved if all farmers were to adopt injection as a method for animal manure application.