1. USDA‐ARS, GrasslandSoil and Water Research Lab.808 East Blackland Rd.TempleTX76502USA
2. Dep. of Geography and Environmental ManagementUniv. of Waterloo200 University Ave. W.WaterlooONN2L 3G1Canada
3. USDA‐ARS Pasture Systems and Watershed Management Research UnitBldg. 3702, Curtin Rd.University ParkPA16802USA
4. Centre for Ecology and HydrologyWallingfordOX10 8BBUK
5. USDA‐ARS, Soil Drainage Research UnitColumbusOH43210USA