Changing Of Cultivated Land Resource And Its Effect On Grain Production In Sanjiang Plains

Cultivated land is the basic of human existence and development, bearing human activity and grain production. Sanjiang Plains is an important marketable grain base in China, and its advantageous natural conditions for agriculture and forestry provided round development of a good foundation. Sanjiang Plains plays an important role in maintaining the supply of grain and the food security of China. This paper study on the changing of cultivated land resource and its effect on grain production, aimed at mastering the influence of cultivated land on grain production under the background of decreasing of cultivated land area, in order to provide reference to the grain production in Sanjiang Plains. The article includes three aspects as follows:1. Analyze the variation characteristic of cultivated land in Sanjiang Plains. The paper analyze the change state of cultivated land in the 27 years from 1986-2012 based on the temporal changes and spatial pattern as well as transfer characteristics of farmed land; Sanjiang Plains has rich farmed land, and the increased speed and range of cultivatedcul land tends to decrease. At the same time the mutual transformation between farmland and other land use type lead to the increase of farmland area, providing guarantee for grain production in Sanjiang Plains; with the gradual reclamation of cultivated land on northeast of Sanjiang Plains, the spatial agglomeration of cultivated land is significant, it determines the concentration region of grain production in Sanjiang Plains.2. Measure the grain production in Sanjiang Plains. Analyze the change state of grain yield,unit area grain yield and per capita account for grain yield, as well as its role in Heilong Jiang province. The results showed that, Sanjiang Plains has formed grain production pattern depend on soybean,corn and rice; and formed spatial pattern of grain production on the northeast of Sanjiang Plains; the status of Sanjiang Plains in food supply continue to strengthen, as well as its role on ensuring food safety.3. Analyze the influence of cultivated land on grain production. The paper study the relationship between grain production and farmed land depends on the gravity center model, correlation analysis and the logarithmic mean weigh division index method(LMID). The results showed that there is a significant correlation between the cultivated land and grain production, and the cultivated land influences the increase and spatial distribution of grain production. Especially in the county whose cultivated land area is reducing, the cultivated land area begin to prevent the grain production from increasing. We also explore the influence of the use quality of farmed land for unit area grain yield. And we should pay more attention on the use quality of farmed land and enhancement the influential effect of farmland quality in order to remedy the negative effect of farmland area.