Investigation And Evaluation On Cultivated Land Fertility Of Shenmu County

Under the background of a sharp drop in quantity of arable land area, the quality of cultivated land has become an important guarantee for agricultural development and security.This paper takes the Shenmu county in Shaanxi Province as the study area, using geographic information system and county land resources management system as the platform, divides the basic evaluation units according to the topographical map, geomorphological map, administrative map, soil map and present land-use map. Combined expert evaluation method, analytic hierarchy process, membership function together to complete the assessment of evaluation factors, the determination of weighting coefficient and the selection of membership function. According to the actual situation of Shenmu county, we build the evaluation system after referred to many domestic and international correlational studies.Using the measured data of the hydrologic station, soil and fertilizer station, with Meta-Analysis method after field investigation and data analysis, made the farmland fertility evaluation in Shenmu county from four aspects of site conditions, soil properties, soil fertility and soil management, so as to provide scientific basis for quality construction of arable land and sustainable development of agricultural production.The results showed that the total cultivated land area is 75045.89 hm2, can be divided into 5 grades. And the top-level is 14141.30 hm2, accounted for 18.84% of the arable land, the second-class is 4742.78 hm2, accounted for 6.32%, the third-class is 29203.51 hm2, accounted for 38.91%, the fourth-class is 25809.38 hm2, accounted for 34.39%, the fifth-class is 1148.92 hm2, accounted for 1.53%.The high-quality cultivated land, such as first-class, second-class and third-class, are mainly distributed in valley-flat with better soil fertility and improved management equipment, it should be targeted to applying organic fertilizer, to improving the structure of soil and reasonable rotation of crops in order to maintain the stability of cultivated land productivity. The fourth-class and the fifth-class cultivated land are distributed in loess hills which soil fertility is lower, irrigation facilities are fewer, and site conditions are poorer. We should construct terraces, level land and strengthen construction of agricultural infrastructure, as far as possible to improve the quality of cultivated land.