A Primary Study on Phosphorus Adsorption of Forest Soils in Xizhang Watershed,Baoshan Yunnan

Soils sampled from the forests in Xizhuang Watershed,Baoshan,Yunnan Province were studied for phosphorus adsorption in this paper.The experiment results showed that P adsorption of the soils could be simulated well by Langmuir equation.Soil parent materials had a significant effect on P adsorption.The P adsorption of the soils derived from limestone was higher than the soils derived from sandstone,but lower than the soils derived from shale.Fe 3+ and Al 3+ in the soils were the most important factors which influenced the P adsorption capability,and the other soil characteristics influenced P adsorption by influencing the content or the activity of Fe 3+ and Al 3+ .Highly significant positive correlation was found between P adsorption capability and the content of Fe 3+ ,Al 3+ ,total nitrogen,organic matter in the soils,and the correlation coefficients were 0 6215,0 6853 and 0 6819,respectively;while negative correlation was found between P adsorption capability and the content of Ca 2+ ,pH,exchangeable base,base saturation,and the correlation coefficients were -0 7366,-0 6802,0 6383 and -0 8730,respectively,all at a significance level of 1%.