Dynamic Change and Forecast of per Unit Area Grain Yield Based on Grey System Theory in Suzhou City

Based on the statistical data from 1991 to 2010, the dynamic change of per unit area grain yield were discussed in Suzhou City. In the last 20 years, the per unit area grain yield took on an increasing trend in the fluctuation, using the GM (1, 1) model, per unit area grain yield will continue to grow in the next five years. According to the grey system theory, factors affecting per unit area grain yield are analyzed and correlative degree between factors and per unit area grain yield is quantitatively measured. The results show that the level of urbanization, modernization of agricultural science and technology and precipitation are the most important factors that affect per unit area grain yield, but economic factors such as GDP have less impact on per unit area grain yield in Suzhou City. Moreover, the construction of water conservancy should be strengthened to improve food production and disaster prevention capacity and focus on raising the level of agricultural modernization in the future. Relying on technological progress to improve per unit area grain yield is an important foundation for the future to ensure food stability during urbanization and economic development, which the cultivated area will continue to decrease.