Abstract:
Abstract: To understand the spatial-temporal variations of cultivated land and grain production and the sensitivity of grain production in counties to cultivated land variation in China during 2000-2010, this paper analyzed the distribution, variation and the shifting of barycenter of cultivated land and grain production, and the response of grain production to the change of cultivated land by means of statistical analysis using the 30 m resolution global land cover data (GlobeLand30) in the year of 2000 and 2010. The results showed that: 1) Cultivated land was mainly distributed in the eastern region of China, and the variation of cultivated land was characterized by the increase in the west, the decrease in the east and the decline of total amount of cultivated land. And the net decreased area of cultivated land was 1 040 300 hm2, and the average annual decrease area was 104 000 hm2. In the conversion of other land types to cultivated land, the conversion of forest land, grassland and artificial surface to cultivated land was the most. The conversion between cultivated land and forest land was mainly concentrated in the southern region; the conversion between cultivated land and grassland was mainly distributed in the northeast, Inner Mongolia, Qinghai-Tibet area and the area along the Great Wall, and the ecological construction projects in these areas have achieved remarkable results; the conversion between cultivated land and construction land was mainly distributed in the North China Plain; and the reserve cultivated land resources in Xinjiang were rich, and the conversion between cultivated land and bare land was the most. 2) Grain production was mainly concentrated in Northeast, North China and South China, and the variation of grain yield was characterized by the reduction in the south, the increase in the north and the increase of the total grain output. 3) From the concentration degree of cultivated land and grain production, the concentration degree of cultivated land distribution affected the concentration degree of grain production distribution, and the concentration degree of grain production was generally higher than that of cultivated land. With the opposition of the direction that the barycenter of cultivated land moved, the barycenter of grain production moved toward the north and the east. The contradiction between grain supply and demand in China has increased, and the pattern of grain production in China has changed to “north-to-south grain diversion”. 4) The grain production of 32.24% of counties showed the dependence on the quantity of cultivated land, which was mainly distributed in the northeast, North China, western region, the area along the Great Wall, southwest area and southeast coastal area. Grain output is not only affected by the quantity of cultivated land, but also affected by the sown area and the intensity of grain planting. In the areas with high sensitivity of grain production to cultivated land variation, we should strengthen the protection of the quantity and the quality of cultivated land and improve farmers’ enthusiasm of grain planting, and in the areas with less sensitivity, more attention should be paid to the protection of cultivated land fertility and the improvement of grain yield per unit area, so as to ensure food security in China. At the same time, the rotation and fallow can be implemented in less sensitive areas, to recover the land fertility without losing the grain production. This study also did the exploring work for the selection and allocation of rotation and fallow areas in China.