The Study Of Food Security Based On Cultivated Land Production Capacity Evaluation With AEZ Method

As the important material of national economic development, food is the foundation for any country to maintain social stability and realize economic development.The cultivated land, which is the main land use form, combining the light, temperature, rainfall, terrain with other natural resources factors, forms crop production function mainly in food. The cultivated land meets the human reproduction meanwhile provides location and material conditions for the development of human civilization. Since the human society entered the 21st century, society and economy develop rapidly and need more land. At the same time, with the population dramatically increasing, the grain production capacity of land cannot satisfy the needs of society in some areas and certain dates, which threatens food security to a certain degree.The FAO food security commission has made a new expression on food security in 1996, "only when all people gained nutritious, security, and enough food in physical and economic to meet its positive healthy dietary needs and food preferences at any time, can we realize the food security". Therefore, food security involves grain production, grain circulation and grain consumption. But food production is the primary problem of food security. The grain production depends on the ability of grain production, thus the comprehensive grain production ability of farmland is the first to ensure for food security. To a certain degree, in order to realize the sustainable utilization of cultivated land resources, the core to solve the food security problemin our country is to protect and enhance the cultivated land security.Agriculture ecological zone (AEZ) is a kind of land production potential evaluation method widely applied in the world. The essence of the method is to divide into small land units with the same properties, consider all factors in land resource productivity comprehensively and systematicly, adopt advanced dynamic simulation model of crop growth to calculate crop prodution through simulating crops growth environment. The result can be inosculated well with actual situation.The research related to the food security and grain production capacity mostly exists in theoretical level at present, and only a few local tests and individual tests did theory verified. Most scholars studied food security with statistical data. But because of different data sources, doubtful systematic theory, small research region, short time span, the reality guiding significance is poor. The case study on grain production capacity and food security evaluation based on ecological method has been reported rarely. Based on the AEZ method and supported by land resources data, the study measured farmland grain production ability of 12 years in Shandong province firstly and systematically. Combining with the trend of population change and the situation of economic and social development, the study dynamically analyses cultivated land change, grain production capability change, regional grain security spatio-temporal rule, evolution tendency and the inner relationship among each factor. The study method had a high enlightenment function in grain production, land management, and food security for better system, detailed data and reliable conclusion comprehensive.Regional grain production capacity is the comprehensive embodiment of cultivated land quantity and quality. Based on the AEZ method, using algorithm design as the technical platform, this research established the relation model on the quantity and quality of arable land and realized the dynamic association between cultivated land change and grain production ability. With wheat and corn as benchmark crops, the study established regional land production capacity analysis model, which combined arable land realistic production capacity calculation, the arable land production potentia calculation with the arable land production ability change analysis. Mastering the quantity change in regional cultivated land dynamically, the model also mastered the production ability and the increase or decrease of the cultivated land dvnamically at the same time. By analyzing the influence degree of the grain production ability caused by farmland change and the change of grain production ability caused by different cultivated land change, combining with economic social development and population changes in Shandong province, the article made an objective evaluation on the level of regional food security. At the same time, it put forward countermeasures and suggestions on the cultivated land protection and the insurance of food security level in Shandong province.The main conclusion was made from this study.1 The total arable land in Shandong province is 7730000 ha. in 2007. while the weighted grade is 6.75. The higher quality of cultivated land is mainly distributed in the northwest and the southwest of Shandong province. The percentage of cultivated land, construction land, hydraulic structure land and transportation land is 52.2%.16.7%.1.7%and 1.1% respectively.From 1996 to 2007. the cultivated area decreased 264 3000 ha.. with the reduction proportion of 3%.The decrease speed of cultivated land area speeds up while construction land has increased significantly since 2001. The relationship between the reduction of cultivated land area and the increases of construction land is linear relation obviously. 2 The grain production capacity change of the cultivated land is the integrated performance with coupling effect of quantity and quality in cultivated land. Besides the arable land area decreased, the falling quality of cultivated land is the important reason of the grain production ability continuing to decline in recent years in Shandong province. Thus, in order to stabilize the grain production ability, the protection efforts in the cultivated land should be strengthen, and the measures of dynamic balance to attach importance to the quantity and quality of cultivated land should be carried out.3 Though the food security of Shandong is in the above the cordon, it continued to decline in recent years. The food reliability had reached on the edge of level, descending from109%to 100%. The food security situation is not optimistic. The population in the period has risen from 843 million to 934.6 million, with the growth of 10.86%. The main factor of food safety risk is the increasing population. The population growth was 5.0932 million people every year and there was no obvious sign of slowing.4 The weighted average of the factors occupied the grain production ability change from.1996 to 2007 showed that the construction occupied the cultivated land is the first factor with the proportion of 33%, while the second is land consolidation with 25%and the third is land development with 22%. Construction occupying cultivated land was the main factors which caused the decrease of the grain production capacity. Land consolidation and land development could not compensate for the reducing number of arable land fully, but played an important role in stabilizing grain crop production。5 Shandong Province should not only protect arable land strictly, but also strengthen the construction land management. Economic developed regions strengthen land consolidation and land development, while undeveloped areas should control the rapid growth of population and increase grain yield level continuously.