Soil Fertility Comprehensive Evaluation Of Cultivated Land Based On GIS At Town And Township Level

Soil fertility comprehensively represents the multiple-fold soil function. It plays an important role in agricultural production. So cultivated land conservation and proper utilization, scientific and precisely evaluation of cultivated land is important to proper development and management .It also has important significant to promote agriculture sustainable development.The paper was conducted on typical towns in Jiaomei and Dongyuan, Longhai, with paddy field, vegetable plot and dry land as main cultivated land use types. The four major evaluating factors to assess the soil fertility Comprehensive evaluation of cultivated land at town and township level were selected and determined by theory of quantification I based on the data of field investigation and soil analysis of the representative plots of cultivated land , and then the soil fertility comprehensive evaluation of cultivated land at town and township level was evaluated by disjoint cluster analysis. The paper compared the evaluation based on 15 evaluating factors with the evaluation based on 4 evaluating factors based on 112 samples by disjoint cluster analysis. The results showed that four factors, including texture, irrigation condition, organic matter content and Pb content were most closely related to crop yields of cultivated land so that these four factors could be used as major evaluating factors to assess the soil fertility comprehensive evaluation of cultivated land in Dongyuan and Jiaomei town. The four factors can represent the most information we need, so the four factors are reasonable and convenience evaluating factors.The evaluation of cultivated land with the four factors by GIS technology and disjoint cluster analysis in Jiaomei and Dongyuan town showed that the cultivated land in Dongyuan town was mainly high level, and the ratio of soil area with high, middle and low fertility amount was to 69.00%, 29.34%, and 1.66% respectively. The cultivated land in Jiaomei town also was mainly high level, and the ratio of soil area with high, middle and low fertility amount was to73.30%, 10.66%, and 16.04% respectively. Compared with the evaluation result of the scale with 1: 50000, the evaluation of cultivated land came close the production more actual, and it was more convenient to application.