POTENTIAL AND LIMITATIONS OF COVER CROPS, LIVING MULCHES, AND PERENNIALS TO REDUCE NUTRIENT LOSSES TO WATER SOURCES FROM AGRICULTURAL FIELDS T.C. Kaspar, Plant Physiologist, USDA-ARS, National Soil Tilth Laboratory; E.J. Kladivko, Professor of Soil Physics, Agronomy Dept., Purdue University; J.W. Singer, Research Agronomist, USDA-ARS, National Soil Tilth Laboratory S. Morse, Senior Fellow, Agronomy/Plant Genetics, University of Minnesota D. Mutch, Cover Crops/Field Crops IPM Specialist, KBS, Michigan State University