Abstract:

Taking Jinchang City as the research area, this paper analyzed the quality grade, soil nutrient characteristics and spatial differentiation of cultivated land within the scope of the city, and provided the basis for scientific fertilization of cultivated land and improving the regional management level of soil nutrient under the condition of ensuring accuracy. As a quantitative method to analyze fuzzy phenomena, fuzzy mathematics has wide application value in many fields. Based on GIS technology, this paper explained how to use the method to evaluate cultivated land quality. Taking Jinchang City as an example, based on the national standard of Cultivated Land Quality Grade, this paper analyzed and studied the spatial distribution of cultivated land quality grade and nutrient content by combination of the county cultivated land resource management information system and GIS technology. The results showed that the quality of cultivated land in Jinchang was in grade 1 to grade 6, with no grade 7 to grade 10. The land of grade 1 was the main cultivated land in Jinchang, with an area of 80024.40 hm², accounting for 64.35% of the total cultivated land in Jinchang. The overall nutrient level of cultivated land in Jinchang was relatively medium, and the content of soil organic matter was mostly low and medium, showing a trend of high in the west and low in the east. Total nitrogen content was mostly low, showing a trend of higher in the southwest and lower in the northeast. The content of available phosphorus was mostly at a high level, and it was generally higher in southwest than in northeast. The content of available potassium was mostly low and medium, with a general trend of high in the west and low in the east. The quality of cultivated land in Jinchang City was good. The soil fertility could be improved by increasing the application of organic fertilizer, increasing the intensity of irrigation, and increasing the popularization of water-saving technology, so as to keep the soil hydrated and fertile.

Key words: cultivated land quality grade, fuzzy mathematics, analytic hierarchy process, county cultivated land resource management information system, soil nutrient