Niche-Fitness Theory and Its Application to GIS-Based Multi-Suitability Evaluation of Tillage

With the theory of sustainable development as guide for the agriculture of China, farmland in Houhu region of the Jianghan Plain in China was selected for case-study on introduction of the niche-fitness theory into multi-suitability evaluation of tillage. Quantitative analysis of niche-fitness and restrictive factors for rice, wheat, cotton and rape, were carried out by means of calculating niche-fitness and limiting factors models. The results indicate that the niche-fitness value in this area is in medium and high side which can be able to meet basic requirement of crops, and the maximum of niche-fitness value reaches 0.7719. The 1,2 level of suitable level is primary, and their percentage averagely accounts for 80%. The suitable area of wheat in this area is maximal, which gets to 30.59%. Contrarily, the unsuited area for crop growth only has to 3.68%. It is proved that available phosphorus, CEC and accessibility level of road are the primary niche factors that restrict tillage productive potential in this area. These results of the study can find direct application to supervision of agricultural production, to reasonable utilization and scientific management of tillage resources.