The Evaluation of Soil Nutrient on Different Restoration Measures in Three Gorges Reservoir Region

We measured soil nutrients in different restoration measures of in Three Gorges Reservoir Region. The effects of different restoration measures on soil pH, organic matter, nutrients and available nutrients were studied, and soil nutrients were analyzed by principal component analysis. The results showed that soil pH values were acidic in the study area, which was relatively low in the soil of profile surface, and it increase with the increasing of soil layer. The organic matter content of soil 0~20 cm under different restoration measures was the highest, and compared with the bare land, it increased significantly under Koelreuteria bipinnata+Cassia suffruticasa, biological border and closed forest measures. The distribution of total phosphorus content showed a great fluctuation with the increase of the soil depth. The available nitrogen declines from the surface soil to bottom soil, at the same time, it showed a surface gathering phenomenon under different restoration measures, except and traditional planting bare land control plot. In addition to the control of bare land, the available phosphorus content decline with the soil depth increased, and it was the highest under the biological border measures. Evaluation of soil nutrients in different restoration measures of comprehensive effect of K.bipinnata + C. suffruticasa measures was maximum (2.308). The bare land control plot was minimum (-2.667). In general, soil nutrient contents decrease with the increase of soil depth, and soil nutrient content can be improved through restoration measures.