Decomposition Analysis For Spatio-Tempral Variation Of Grain Production In Jiangsu Province

Based on the combining use of qualitative and quantitative analysis methods, the agricultural statistical data from 1978 to 2010 of Jiangsu Province was analyzed, and the timing and spatial variation characteristics of grain production in this province are studied. The factors decomposition method is used to analyze the changes in factors which affect grain production, and the main conclusions are as follows:(1) The grain yield changes in a fluctuating way after fast growth stage. The center of grain production transferred to the north part of Jiangsu Province in the past three decades. As the increase in the rice yield is getting smaller, wheat instead of rice became the main yield-increasing crop in the 1990s. Grain yield and its change are decomposed into grain yield per hectare effect and grain sown area effect. Variance in grain yield per hectare accounts for nearly 67 percent of the variance in grain yield, while there is a weak positive correlation between sown area index and grain yield.(2) The fluctuation of grain sown area depends on the fluctuation of rice sown area. Wheat is the only grain crop that sown area has increased among the three major grain crops in Jiangsu province. The variance in grain sown area is highly correlated to its planting rate followed by the multiple cropping index and cultivated area. The reduction of grain sown area is mainly due to three factors: shrinking share of grain crops, the decrease in arable land,and the increased multiple cropping index which is the only supplement, but it has little effect on the total decrement.(3) Temporal and spatial variation in grain yield per hectare comes from two sources:differences in the yield levels of each crop, and differences in the composition of cropping types. The variance in productivity of grain crops accounts for nearly 96 percent of the variance in grain yield per hectare, while there is a weak positive correlation between composition index and grain yield per hectare. To the late, because of the grain productivity index on the decrease, the increment of the grain yield per hectare has declined, while the composition turns into yield-promoting effect from the negative yield effect, which become the important supplement to increase grain yield per hectare in Jiangsu Province.(4) Grain production in south Jiangsu became atrophic, however, the grain production in north of Yangtze river area has been greatly improved since 1997, especially in Huaian, Yancheng and Lianyungang, city in the north of Jiangsu Province, where have became the most important grain production areas.(5) North Jiangsu has more grain yield increment than south Jiangsu due to the higher increase in grain yield per hectare, and increased grain sown area since 1997. The results show that the decrease of the cultivated area results in the reduction of grain sown area in south, and the increase of the multiple cropping index lead to the increase of grain sown area in north of Yangtze river area. Spatial variation in grain yield per hectare in Jiangsu Province due to productivity effect which strengthened by composition effect. It is thus argued that the high yield levels of grain crops and the high-quality grain production target to shift in south result in the productivity index is smaller there than this in north. The spatial variation in rice cropping area is the main influence factor for the spatial variation in the composition effect.Based on the results of the study, some suggestions were proposed to promote the sustainable development of grain production in Jiangsu Province. First, protecting the cultivated land consciously to stabilize the sown area of the cereal crops. Second, assembling the cultivation technique of the related cereal crops and increasing grain yield per unit area. Third, The north region of Jiangsu should center around grain production to stabilize and improve the ability of grain production, also Jiangsu should consolidate and expand the regional cooperation between productive region and sale region. Fourth, adhering to the path of urbanization with Chinese characteristics and fostering the sound development of urbanization, and developing new industrialization.