[1]State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau/Institute of Soil and Water Conservation;
Northwest A & F University;
Yangling 712100;
P.R.China;
[2]College of Forestry;
Shanxi Agricultural University;
Taigu 030801;
P.R. China;
[3]College of Agriculture;
Shanxi Agricultural University;
Taigu 030801;
P.R. China;