Dynamic Equilibrium of the Total Cultivated Land in China in a New Situation

Cultivated land plays an important role both in agricultural development and in economic development of China.Cultivated land protection has been regarded as a basic national policy of China.In order to solve the increasing problems of cultivated land resource shortage and food security in China,a land management policy of dynamic equilibrium of the total cultivated land has been implemented since 1996.However,the fierce trend of cultivated land resources' quantity decrease and quality degradation is still out of control.Based on the severe condition of dynamic equilibrium of the total cultivated land and the land resources change tendency in China,this paper defines the connotation of dynamic equilibrium of the total cultivated land in new situation from the new perspective,pointes out that the dynamic equilibrium of the total cultivated land is a systems engineering,this system includes at least three subsystems,namely cultivated land subsystem,population subsystem and output of per unit area subsystem,these three subsystems must be compatible.Then this paper establishes the dynamic equilibrium index which is used to evaluate the dynamic equilibrium of the total cultivated land.The status quo of dynamic equilibrium of the total cultivated land is evaluated by the dynamic equilibrium index,the evaluation results indicate that the number of provinces which have realized the dynamic equilibrium of the total cultivated land decreased from 13 to 7.This reflects the severe situation of cultivated land further.Furthermore,the spatial-temporal differences of dynamic equilibrium of the total cultivated land in China are analyzed,the analysis results indicate that both the quantity of cultivated land area and the quantity of grain-sown area are decreasing in most of provinces;the population of our country will be inevitably increasing in the next decade;the output of per unit area in 17 provinces has increased in the past 7 years,but the average output of per unit area of the whole country is still decreasing.Accordingly,countermeasures for achieving the overall dynamic equilibrium point of Chinese cultivated land have been thought out,such as rational proportion between grain crops and cash crops,the more attention to the quality of cultivated land and the high-efficient utilization of agricultural resources etc.