关键词: 细胞因子, 细胞因子

Abstract:

In order to study the security status of cultivated land of Jiangsu Province to provide the basis for effective utilization, protection and administration of cultivated land, the degree of pressure of cultivated land use in Jiangsu Province and causes of that were analyzed, based on which revised data of Jiangsu province from 1971 to 2009 were selected, and the minimum area of cultivated land per capita and pressure index of cultivated land in this region during this period were calculated. The results indicated that pressure index of cultivated land showed a downward tendency in the fluctuation due to implementation of the household contract responsibility system; since the 2000s, the grain comprehensive production capacity that was decreased by natural calamities frequently occurred and the slipped grain growing activism of the peasant, began to impose pressure on the cultivated land of Jiangsu Province, but the pressure had been relieved in recent years. By the end of 2009, there had been a considerable discrepancy in the degree of cultivated land pressure between the thirteen prefecture-level cities of Jiangsu Province, among which the cultivated land of Nanjing, Wuxi, Suzhou and Changzhou had been bearing a tremendous pressure, and the cultivated land pressure of Xuzhou, Zhenjiang, Nantong had began to emerge, while that of the others had bear no pressure. The study on the cultivated land pressure based on grain security showed that there were two approaches to relive the cultivated land pressure of Jiangsu Province, one of which was to enhance the grain comprehensive production capacity of the cultivated land, while another one of which was to prevent continued loss of the cultivated land.