Safety Threshold Of Arable Land Based On Demand Of Agricultural Comprehensive Production Capacity

Since the 90s of the 20th Century, the increasing rapid of food production has slowed down, even became negative in some year, while the demand of food has been increasing continually. As a result the demand of food has exceeded its supply in 2002, and the stock of grain is also declining in the world. The recent price rising of food has aroused attention of the whole world. According the study of many experts, the reason of food price rising is decrease of food supply, and the further reason is continual decrease of arable land used to produce food. Arable land resource is the carrier of agricultural comprehensive production capacity. Considering the consistent development of agriculture and final factor of food security, the guarantying capacity of agricultural produce by arable land resource must be advanced to solve the problem of farm produce supply, especially food.This dissertation studied the critical issues of food security and arable land resource. The ultimate aim of agricultural production is to satisfy demand of the development of society and economy, beginning with the analysis of this aim, the dissertation measured the demand of arable land resource in 2020 and 2030 in China based on the forecast of farm produce demand, and evaluated the safety status of arable land resource. The dissertation expects a quantificational conception of arable land tension in China to offer more scientific reference for establishment of the policy of arable land security, agricultural production and farm produce trade.The dissertation includes following contents: (1) The conception of agricultural comprehensive production capacity, arable land resource security and safety threshold based on the existing study achievements; (2) The driving forces of arable land change and its operation mechanism were analyzed, quantity of arable land was confirmed from 1987 according to the data issued by the land and resources department, and tenure amount of arable land in 2020 and 2030 was forecasted considering the distribution of changing rate of arable land amount; (3) According to the conception and meaning of agricultural comprehensive production capacity, the dissertation took the production of grain, cotton, Oil Crops, and sugar plants as the representation of production capacity of arable land, because they count for much to the people's livelihood and society stable, and analyzed spatio-temporal changes of these farm produces; (4) Factors influencing demand of farm produces were analyzed, and demand of farm produces in 2020 and 2030 were forecasted based on the farm produce consumption data which includes information of consumption and meal habit forming in long period; (5)The study established measuring model of arable land demand, and calculated the safety threshold of arable land in 2020 and 2030 after the forecast of cropping index, utilization structure of arable land, adjusting coefficient of grain production capacity, yield of crop, sufficiency rates of farm produces, and influencing coefficient of natural disaster. And the security status of arable land was evaluated also; (6) Some measurements were put forward to ensure the agricultural comprehensive production capacity guaranteed by arable land resource according to the conclusions of the dissertation.The dissertation educed the following conclusions:(1)The arable land area was increasing as a whole before the beginning of 90s of the 20th century, but after that time it has been decreasing. The tenure amount of arable land will be 1.17×108hm2 in 2020 and 1.13×108hm2 in 2030;(2)The agricultural comprehensive production capacity has gain a huge increase, but because it becomes very difficult for cropping index and yield to increase greatly the improvement of agricultural comprehensive production capacity will be difficult also in China;(3)With the increase of population, income and urbanization rate, demand of farm produce will continually increase. According to the result of forecast, the demand of grain, Oil Crops, sugar plants and cotton will reach 5.706×108 tons, 1.119×108 tons, 1.32×108 tons and 0.146×108 tons in 2020,6.123×108 tons, 1.443×108 tons, 1.565×108 tons and 0.188×108 tons in 2030;(4)The safety threshold of arable land will be 1.10×108hm2 in 2020 and 1.12×108hm2 in 2030,and the arable land guarantying of agricultural comprehensive production capacity will decrease ceaselessly before 2030. Under the same combination of sufficiency rates of farm produces, the pressure index continually increases which indicate that improvement of agricultural comprehensive production capacity is slower than the increase of farm produce demand.According to the conclusions, some suggestions was put forward, such as to establish effective basic protective system to ensure security of arable land resource, to improve arable land quality, and to enhance the contribution of science technology progress.