This dissertation will help to the establishment of policy to strength food security, facilitating structure adjustment, enhancing resource usage efficiency according to comparative advantage.

• 本论文的结论将有助于为我国在新的国际经济环境下保障粮食安全，调整农业结构，发挥农业比较优势，充分利用国内外两个市场、两种资源，提高农业比较利益提供科学决策依据.