EVALUATION OF BESTMANAGEMENTPRACTICES TO CONTROL PHOSPHORUSNONPOINTSOURCEPOLLUTION

The Guelph model for evaluating the effects of Agricultural Management Systems on Erosion, Sedimentation and Phosphorus yields (GAMESP) has been used toevaluate potential reductions in downstream sediment and phosphorus loadings from agricultural land when best management practices are applied on problem areas of a small Ontario agricultural watershed. This paper introduces a brief overview ofdifferent means of controlling phosphorus nonpoint source pollution, and reveals that best management practices using a crop residue cover such as no-till and spring moldboard plowing can potentially reduce downstream phosphorus loadings, attributed tosheet and rill erosion during the hydrologically active spring period byas much as 83 and 74%, respectively, when compared to fall moldboard plowing without a crop residue cover.