Suitability evaluation on high quality capital farmland consolidation based on niche-fitness model

Abstract: It is China's significant strategic move to carry out rural land consolidation and construct high quality capital farmland on a large scale, which ensures stable yields despite drought or excessive rain. However, the construction project of high quality capital farmland is currently with the lack of scientific instruction in line with local conditions in respect of project site selection and design approach. An empirical research was conducted in Xinzheng City to study suitability evaluation and obstacle indicators of high quality capital farmland. Based on the theory of ecological niche and the construction target of high-quality capital farmland, this paper proposed the very concept of high quality capital farmland niche, and established the index system from the different aspects of natural resource endowment, infrastructure, sustainability of high quality capital farmland and its space stability. Thirteen indicators were selected during the evaluation. Then this paper built the niche-fitness evaluation model. Throughout the evaluation model as well as the matching degree between the actual niche and the first-rate niche, 4 levels were divided to pinpoint the niche of the high quality capital farmland in different regions. The farmland in the first level areas was high quality capital farmland; the farmland in the second level areas needed to be improved; the farmland in the third level needed to be comprehensively renovated; and the farmland in the fourth level was not appropriate for exploitation. This paper clarified the niche of the high quality capital farmland in different regions, took the first-rate niche as the sole criterion to establish the diagnosis model of obstacle indicators, analyzed the restricted degree and diversity of the obstacle indicators, clarified the priority and orientation on capital farmland construction in different regions, and sought countermeasures and valid paths. The results were as follows: 1) 14 017.72 hm2 farmland was high quality capital farmland, accounting for 25.88% of the city's farmland, 21 121.15 hm2 farmland needed to be improved, accounting for 38.99% of the city's farmland, 4 559.37 hm2 farmland needed to be comprehensively renovated, accounting for 8.42% of the city's farmland, and 14 469.70 hm2 farmland was not appropriate for exploitation, accounting for 26.71% of the city's farmland; 2) In Xinzheng City, the arable land was in a good natural endowment, and the security of irrigation and soil pollution index were the main obstacle indicators; 3) Using the niche-fitness model to pinpoint the niche of high quality capital farmland, could extend the application range of the theory of ecological niche, solve the problems including indeterminate key rectification regions and unreasonable project locations, and provide the theoretical basis for project site selection and design approach.