1. USDA‐ARS Appalachian Farming Systems Research Center 1224 Airport Rd. Beaver WV 25813
2. Dep. of Crop and Soil Environmental Sciences Virginia Polytechnic Institute and State Univ. 245 Smyth Hall Blacksburg VA 24061
3. West Virginia Univ. 1078 Agricultural Science Building, P.O. Box 6108 Morgantown WV 26506‐6108