The Research On The Potential Of Cultivated Land Productivity Increase In The Three Gorges Reservoir Based On Food Security

Food security is a hot issue in21th century. With the process of industrialization and urbanization, the quantity of cultivated land was gradually decreasing nationwide, which has been a threat to China’s food security. It is not only a significant strategy issue related to the national economic development and social stability, but also a realitic question on the guarantee of food security and the demand for agricultural product to control the decrease of cultivated land, increase the effective area of cultivated land through various approach and improve the quality of the existing cultivated land.Therefore, it is extremely important to promote the productivity through researching the quantity and quality of cultivated land.Wanzhou, where full of mountainous and hilly,with various landform, complex geological condition, located in the core of the Three Gorges reservoir, is the ecological conserving region according to the functional division in Chongqing. However, the ecological conditions with both advantages and vulnerability. There are several important problems should be solved, including how to guarantee the ecological construction, the responsibility of the ecological barrier for Chongqing metropolis, developing the economic and guarantee the life of people as well as developing the economy in reservoir area and take advantage of the limited cultivated land.In this study, we analyzed the problem of cultivated land utilization in Wanzhou district by field reconnaissance and investigation among townships together with collecting the data and figure material from the related department. The potential to enhance the quantity and quality of cultivated land is analyzed and graded through the method of mathematical statistics and studying on the potential of production improvement after readjustment by calculating the reality production capacity、 realizable capacity and theoretical capacity. Additionally, principal component analysis and cluster analysis have been used to synthetical classify, readjustment and regionalize aimed to provide the evidence of food security in this area. The main conclusions concluded as followed:1. Cultivated land is limited and its utilization is not reasonable. The slope land covers large area as well as the land with lower production. The slope land over15°covers46.99%of the total area, and those inappropriate farming land over25°covers6.44%. Among all the cultivated land, the low productive land covers36.06%and37.57%for middle productive land, which indicated the potential to be readjustmented. The population of Wanzhou reached to1.7509million in2012and the food consumption was700491.84t, the area of cultivated land was99371.41hm2, food production was521523.00t the deficit of food is179468.84t, the coefficient of food security was74.45%.The productive capacity of cultivated land is too low to guarantee the food security of Wanzhou. It plays a positive role in the economic development and food security with limitedly exploit the reserved resource of cultivated land in Wanzhou, and improve the quality and productive capacity through readjustment as well as strictly control the occupation of cultivated land.2. The backup resources of arable land in Wanzhou is insufficient and they are limited to develop into cultivated land. However, it is still potential to increase cultivated land by enhancing net cultivated land coefficient through decreasing the field ridge coefficient, consolidating cultivated land and reclamation. Based on the new exploited cultivated land coefficient, the area of effective cultivated land can be increased by7408.22hm2by consolidating the slope land among6°o25°which is covering81376.65hm2, using the method of calculating the potential, the area of effective cultivated land can be increased by1124.84hm2by exploiting the proper reserved cultivated land of1730.52hm2. The synthetical could be increased cultivated land area reaches to8533.06hm2,average increased cultivated land coefficient is9.10%,the total acreage of cultivated land could reach to107904.47hm2.3. There is lot of advancement in the quality and productive. The quality of cultivated land can be enhance1-2level by consolidating and improving the condition of cultivated land. According to the yield per unit in farmland grading and the grain yield per unit after improvement of cultivated land area and quality by consolidating, the theoretical total production is980696.05t and the realizable total production is891266.87t.4. Wanzhou can be divided into5grades potential regions according to the realizable improvement coefficient>100.00%>75.00-99.99%、50.00-74.99%、25.00-49.99%、<25.00%.The comparison of theoretical potential and realizable potential indicates that the number of towns with boost of productive capacity of cultivated land is much smaller than theoretical number, which is caused by the limitation of condition for development.5. The study on synthetically cultivated land readjustment and regionalizing. By Cluster Analysis with the main index factors influencing the quality of cultivated land which are obtained through Principal Component Analysis, the52towns(streets) can be classified with4categories according to the similarity of potential to be synthetically consolidated. The first category includel2towns like Yanshan Township; The second one includes9towns like Longsha Town; The third one contains26towns within Town of Danzi and the fourth category includes Ganning Town. In terms of the similarity of potential to be synthetically consolidated and combined with different requirement of economic development, orientation of land utilizing and construction of ecology in different regions, it can be divided to different consolidating regions (1) Ecological consolidated region at the edge of mountain, including11towns like Lishu Township;(2) Synthetically consolidated region along the river, including21towns like Longdu Street;(3)Farmland consolidated region in hilly areas, including19towns like Sunjia Town.The potential of cultivated land readjustment would only demonstrate the possibility of improvement of grain productive capacity by enhancing the quantity and quality of cultivated land on the current basis, under the circumstance of the cultivated land is occupied for city construction continuously along with population increase and urban development, it is necessary to control the cultivated land decrease strictly and balance the cultivated land relatively in order to ensure food security through cultivated security. The population of Wanzhou is predicted to be2.085million and the demand for food is834006.00t in2020, compared with the data of2012,the population has increased by19.08%and the demand for food has increased by133514.00t; Besides, the increased part can’t counteract the decrease caused by various factors according to the prediction for increase and decrease part of cultivated land in Wanzhou in2020. The area of cultivated land in Wanzhou will be97453.52hm2and the quantity of cultivated land will decrease by1917.89hm2compared with it in2012. Calculated with the realizable yield per unit of food by improving the productive capacity after readjustment, the total capacity of cultivated land in theoretical will be885757.50t in2020and the realizable total capacity will be804837.60t. In terms of the realizable total production, it is close to the demand for food in2020in Wanzhou which is834006.00t and the food security coefficient will be96.50%, the deficit of food decrease from179469.00t in2012to29168.40t in2020and the food security coefficient will increase by22.05%, but the challenge about cultivated land and food security in Wanzhou still exists.As the reservoir area, plenty of the cultivated land in Wanzhou has been drowned and it is required to conduct the ecological construction on the slope land over25°by returning the grain plots to forestry as a ecological defence for metropolis, which is the cost and dedication of Wanzhou as the Three Gorges reservoir. However, it also attains a good opportunity to make great progress, not only the support from the country but also the financial and technique support from other developed provinces, which providing good foundation and powerful policy and fund support to the readjustment of cultivated land, the improvement of productive capacity and adjustment of agriculture construction. In the future, although the development of agriculture is mainly based on excavation the content while partially based on extension and the improvement of productive capacity could alleviate the contradiction food supply and demand, It is a urgent affair to control the development intensity of the other industries except agriculture properly and ensure the quantity of cultivated land in the ecological conserving region like the Three Gorges reservoir region.