Study About The Least Cultivated Areas Of Chongqing Based On The Grain Security

The problem of grain security dated back to antiquity, but did not become a focus of research arousing wide attention until the 1970s worldwide grain crisis. The word "Grain security", first appeared in China in 1973, was put forward as a policy goal against the word-wide grain crisis at that time. The characteristic of the situation of our country is that our country has more people and less land. The current population is about 1.3 billion, and in 2030 the population will reach about 1.6 billion, so food has always been the most important task that is concerned about and attached importance to by the Chinese government. In recent years, the steady declination in the acreage of cultivated land caused that grain sown area of our country shows a downward trend, it brings directly the grain problem.The cultivated land is the fundamental reliance of human survival and development, and no substitute could be found as the production material to obtain grain and other farm produce, and it plays a fundamental role on the sustainable development of agriculture and the national economy. Therefore, keep a certain amount and quality of cultivated land resources and the basic food supply directly relates to economic development, social stability and national security.Based on description of the connotation and external quality of the least cultivated area, the paper is instructed by land scarcity theory, sustainable and man-land relationship theory, geographical diversity in use efficiency of the cultivated land theory, game theory, the input-output theory, external theory, and so on. The situation of the grain security in Chongqing, the main problems about the cultivated land and the main restricting factors in the use of the cultivated land are analyzed. According as the principle about relation between mummers, The influence on grain production from the number of the cultivated land is analyzed. And the paper makes use of mathematical models to forecast population, per capita grain consumption and demand, the total demand for grain, the output of the grain crops acreage ,duplicate index and the scale of the grain crops acreage accounting for the total sown are analyzed of chongqing. At the above all, considering on self-sufficiency in grain, the least cultivated areas of 2007-2020 are forecasted using the forecasted model, the predictive values are analyzed about the rationality and a reasonable, and measures and proposals are put forward based on the grain security strategies under the cultivated land protection.The conclusions are as follows:Firstly, the thesis analyzed and researched statistical date for grain of Chongqing, the drawed such a conclusion that the trend emerged from the self-sufficiency to the net redeployment about the balance of supply and demand of the grain since 1999. In addition, through evaluating the situation of the grain security in Chongqing by the fluctuations in grain output index, the level of the grain self-sufficiency rate, the level of grain reservation, and so on, the result showed that Chongqing had a higher level of the grain. However, in the process of using the cultivated land resources, it had emerged such problems that the gross of the cultivated land had decreased trend, the quality of the cultivated land declined, the ecological environment of the cultivated land deteriorated, the cultivated land wasted seriously and the use of the cultivated land had low efficiency. The protection of the cultivated land was mainly restricted by the following three aspects: the first is population, the second is economic development, the third is the protection of the ecological environment. So from the point of view of the grain security, the protection of the cultivated land was of great significance.Secondly, through analyzing the impacts of the recent amount of the cultivated land on the sown area of the grain and the output of grain in Chongqing, the results showed that it had the correlation between the change rate of the cultivated land area and the one of the sown area of the grain. The correlation coefficient was 0.825. It showed that the area of the cultivated land had certain restriction on the sown area. But it had positive correlation between the change rate of the cultivated land area and the one of the grain output, and the correlation coefficient was only 0.140 and did not reach significant levels. However, it is rigid that reduction of the area of the cultivated land leads that the grain declines. Therefore, to guarantee a certain amount of the cultivated land is very important to the total grain output.Thirdly, In this paper, based on the certain rate of the grain self-sufficiency and the level of consumption, the forecast of the least cultivated area is the lowest area of the cultivated land that is demanded according as its own regional comprehensive productivity of the cultivated land (it is reflected by the unit grain yield of the cultivated land). That is, in the grain self-sufficiency rate of 90% and 95%, the least cultivated areas that are forecasted are separately 2.1573 million hectares and 2.2771 million in 2010 in Chongqing. And according to the demand of "10th five-year" social economic development plan of Chongqing and the control index of the overall land use planning of the department of Land and Resources, the least cultivated area of the city is 2.3705 million hectares (35.5571 million a) in2010.They are almost close. Therefore, we can use the model to forecast the least cultivated areas of 2015 and 2020 in Chongqing, and it can provide reference guideline for the government to use the cultivated land rationally.In addition, in the face of the word-wide grain crisis, this study inspires that the improvement of the urbanization can not be as the economic development objectives in various regions of our country. It is that ensuring a certain amount of the least cultivated areas achieves the grain security in order to shake off the shadow of hunger. This is the specific reflection to implement scientific development ideas, so that the economy and the society achieve the sustainable development.