The impact of human disturbances including grazing
cultivation and anti-grazing(from 1987
1997
2003 respectively) on nutrients contents(N
P
K and organic matter) in typical grassland soil was studied in the paper.The result showed that cultivation and grazing can lead to a decrease in nutrient contents of soil
especially topsoil
and cultivation affects it more significantly than grazing;Banned-grazing can increase nutrients contents of soil
which increase with banned-grazing period.At the same time
there exist significant minuslinear dependency relationship between the total N
available N
organic matter and soil depth;there exist second power function relation between available P
available K and soil depth.The total P contents increases with the soil depth
and the total K decreases with it
but the dependency relations were not significant.It is concluded that anti-grazing can increase the nutrient contents in grassland soil and restrain the degradation of grassland soil.