Effects of Land Use on Soil Quality in Karst Hilly Area

The effects of land use on soil nutrients and soil bulk density in Karst hilly area was studied.The results indicated that deforestation and cultivation led to increase in soil bulk density and decrease mostly in soil nutrients.Compared to forest,the bulk density value of bush forest,low growing bushes,grassland and 3 years decultivated land increased by 32%,20.3%,46.9% and 52.3% respectively.Most soil nutrients except total K in grassland and 3 years decultivated land decreased significantly in comparison with forest.Grassland wintnessed a decrease in soil organic matter by 29.3%,total N by 48.2%,total P by 66.3%,alkalysis N by 45.8%,available P by 56.3% and available K by 60%;While 3 years decultivated land saw a decrease in soil organic matter by 85.6%,total N by 84.7%,total P by 81.4%,alkalysis N by 74.9%,available P by 87.5% and available K by 90.6%.The results of soil degradation index showed a severe degradation occurred to grassland and 3 years cultivated land.