Abstract:

As the most valuable land resources，cultivated land is very important to agricultural production，which has some functions，such as production，the landscape culture，ecosystem services and so on. Evaluation on cultivated land ecological security is greatly helpful for improving the state of cultivated land ecosystem and sustainable cultivated land use. On the basis of defining the meaning of cultivated land ecological security，the evaluation index system for cultivated land ecological security was constructed based on the PSR model，then an empirical analysis was conducted in China by entropy method and obstacle degree model. The results showed as follows.（1） The level of cultivated land ecological security in China had been gradually improved from 1996 to 2010，with the index increasing from 0.484 4 to 0.626 9. The degree of cultivated land ecological security in China generally experienced two stages，i.e.，criticality safety and Safer. （2） The pressure index generally showed a downward trend，while status index and response index showed a rise trend. （3） In the long run，the system pressure was found to be the major factor affecting cultivated land ecological security in China. The obstacle degree of system pressure and system status increased by an annual average of 5.33% and 0.52%，respectively，but the obstacle degree of system response decreased by an annual average of 8.02% in China. （4） The pesticide load per unit of cultivated land，fertilizer load per unit of cultivated land，per capita cultivated land，land reclamation rate，and extent of soil erosion were verified to be the key obstacle for further improvement of cultivated land ecological security in China. The cultivated land ecological security was continuously improved by further transformation of economic development mode，promoting the strategic adjustment of economic structure，optimizing the layout of industrial upgrading，strengthening supervision and management for land utilization，improving the degree of land resources market allocation，effectively increasing the land use intensity，reducing economic growth on excessive consumption for land resources，vigorously developing green agriculture，accelerating the agricultural science and technology innovation，rational application of pesticides and fertilizers，effectively reducing pollution for cultivated land resources，carrying out rural land consolidation，strengthening highstandard basic farmland construction，increasing the amount of cultivated land，improving the quality of cultivated land，increasing the investment for environmental protection，increasing the intensity of environmental governance，effectively controlling soil erosion，and so on.