1. USDA‐ARS, Coastal Plains Soil, Water, and Plant Conservation Research Center Florence SC 29501 USA
2. Instituto de Ciências Agrárias Univ. Federal dos Vales do Jequitinhonha e Mucuri Unaí MG 38610‐000 Brazil
3. Dep. of Natural Resources and the Environment Univ. of New Hampshire Durham NH 03824 USA
4. USDA‐ARS, Pasture Systems and Watershed Management Research Unit University Park PA 16802 USA
5. Dep. of Agriculture, Nutrition, and Food Systems Univ. of New Hampshire Durham NH 03824 USA