8[1]Shi Z H,Cai C F,Ding S W.Soil conservation planning at the small watershed level using RUSLE with GIS:a case study in the Three Gorge Area of China.Catena,2004,55:33-48
9[4]Nair P K R.Soil production aspects of agroforestry.International Council for Research in Agroforestry,Nairobi,Kenya,1984
10[12]Soil Survey Staff.Soil taxonomy,a basic system of soil classification for making and interpreting soil surveys.Agric.Handbook,1999,436
