Abstract:

Implementation of agricultural land use policies may greatly impact regional agriculture in production mode and development path. A case study of the Dianshan Lake region of Shanghai was performed using a multi-criteria analysis framework for land use policy effects and a comprehensive index system encompassing societal,economic and ecological factors established in the study,to simulate and evaluate effects of agricultural land use in different scenarios( basic scenario,benchmark scenario and scenarios of three different policies),with the scenario analysis method and Techno GIN model. Results show that the policy of soil-testing-based fertilizer recommendation encourages the farmers to raise K / N ratio in fertilization,and as a result,the yield of rice increases somewhat,but the policy does not significantly reduce total N input and consequent N leaching. However,the policy of site-specific nutrient management( SSNM) further rationalizes the K / N ratio,while reducing total N input and consequent N leaching,but it calls for too much labor,which limits implementation and popularization of the policy. The major effect of the moderate-scale management policy is reduction of labor input,thus freeing more rural labor for off-farm employment. The methodological framework as presented here proves to be a useful tool for evaluation and prediction of agricultural land use effects in China,and the findings in this study may serve as reference for the scientific management of suburban agricultural sustainable development in Shanghai.

Key words: suburban agriculture, land use effect, policy effect, scenario analysis, simulation analysis