1. Northwest Watershed Research Center, USDA Agricultural Research Service, 800 Park Boulevard, Suite 105, 83712, Boise, ID, USA
2. Institute of Geographical Sciences and Natural Resources Research, and Graduate School of the Chinese Academy of Sciences, Beijing, China
3. National Soil Tilth Laboratory, USDA Agricultural Research Service, Ames, IA, USA
4. Institute of Geographical Sciences and Natural Resources Research of the Chinese Academy of Sciences, Beijing, China