Evaluation on multi-suitability of cultivated land based on GIS and niche-fitness model

The cultivated land in Poyang Lake region and its surrounding area of Jiangxi province was selected for multi-suitability evaluation by introducing the niche-fitness theory and Kriging method. The means of weighted average and limiting factor models were adopted to quantitative analyze niche-fitness and restrictive factors for rice, rape, cotton and sweet potato. The result shows that the niche-fitness value in the area is higher in general with the peak value reaching 0.9824, and habitat conditions in the region can basically meet the requirements of the crops; The farmlands of rice, rape and cotton are mainly in grade 1 and 2, which account for the area of 67%. Sweet potatoes which are grade 1 and 2 account for 56.9%. In terms of niche-fitness evaluation, area of rice ranks first with the ratio amounting to 56.1%, cotton comes the next; Total phosphorus, OM, and thickness of cultivated layer are the primary niche factors which restrict land productive potential in the area. The results provided direct application in supervision of agricultural production, and promoted reasonable utilization and scientific management of farmland.