Analysis of driving factors of grain production security in Shaanxi.

According to the statistical data of Shaanxi province in the recent years,the grain total output,cultivated land area,yield per unit area were analyzed.The results indicated that: the grain total output and yield per unit area had similar changing rule,and they all showed a rising trend;the cultivated land area was declining,but the process was slow.The grain total output was controlled by cultivated land area and yield per unit area.When the cultivated land area declined gradually,the increase of grain total output must depend on the great increase of the yield per unit area.The main restrictive factors of yield per unit area included natural disaster,agricultural infrastructure and agricultural input,ecological environment,land policy,quality of cultivated land,the level of agricultural science and technology,culture competence of labor force and so on.