1. U.S. Salinity LaboratoryRiversideCA92507
2. Dep. of Environmental SciencesUniversity of CaliforniaRiversideCA92521
3. Dep. of Crop and Soil Sciences116 ASI Building The Pennsylvania State UniversityUniversity ParkPA16802
4. Pasture Systems & Watershed Management Research UnitUSDA– ARSBuilding 3702 Curtin RoadUniversity ParkPA16802