Comprehensive Evaluation Model Of Soil Nutrient

With the social and economic development. Human destruction of the environment become serious with the population increasing. It becomes increasingly significant that the loss of the content of each element in the soil. Soil conditions directly affect the growth of plants. It’s important for us to do the investigation, analysis and control the loss of soil nutrient. With reference to soil classification criteria of Anhui Province, we give a brief summary of the issues of rural surface soil nutrient loss through the study of the major element content of the soil differences. We established the soil loss model, according to some of the data and information abstracted from the soil test report on the mountain areas of south Anhui Province. Finally we could confirmed the main factors affecting the soil and presented the soil nutrient loss distribution intuitive by these mathematical model.At the same time. in the study of soil nutrient loss also can’t ignore the influence of soil erosion, because soil nutrient loss is closely related to soil erosion process. Soil erosion model as an effective and quantitative study of soil erosion tool plays an important role in study of soil erosion process and guide the practice of water loss.As the background of the soil nutrient loss status for She County the mountain arear in south of Anhui province, the topics obtained the main results as follows:(1) A reasonable sampling techniques is important to select characteristics of sampling points. It provides a reliable basis for the follow-up study. By using direct sampling to select sample, which to portray the whole region of the nutrient distribution, in order to evaluate the whole area of the soil nutrient balance, and then form the best nutrient management strategy of the region.(2) Through research on the spatial variability features and rules of soil nutrients in the study area of farmland for 11 kinds of elements(Organic matter, N, P, S. K. Cu. Fe, Mn, Zn, B, PH value, etc.). we produced a distribution of mountains in southern She County effective nutrient and soil variation diagram. In the basis of the actual situation that soil erosion leads to soil nutrient loss and the differences in soil nutrient loss, nutrient loss model is set up, and then give guidance in order to improve and protect the soil for the reasonable farming.(3) Make full use of advanced technology of RS, GIS and BP neural network theory combined with the development of the trend.And compare the associated gray to principal component analysis model, we final give the soil hierarchy model of BP neural network.