Inputs contribution to grain production increase from 2004 to 2012 in China

This article calculated the input contribution to the production increase and its growth rate of rice，wheat and corn using provincial panel data from 2004 to 2012 in China. Results showed that：（1）The output elasticity of planting area of rice，wheat and corn was much larger than material service input intensity，and the labor input intensity did not pass the significance test.（2）Though the production of rice，wheat and corn increased from 2004 to 2012，the growth rate gradually decreased. The input contribution to the growth rate of rice，wheat and corn was 80% on average and the planting area was the main reason of growth rate decrease.（3）The proportion of contribution of planting area gradually increased for the growth rate change of rice production，and yet decreased for the growth rate of wheat production. The proportion of contribution of input factors of corn had no evident change. This article concluded that， to maintain and to expand the planting area was the base of grain production，while the key measure was protecting the cultivated land. Furthermore，scientific and reasonable agricultural input policy and mechanism should be made targeted to different crop varieties.