A Comparative Study on the Changing Yield Trends of Three Major Grains between China and Major Grain Producing Countries
The yield of major grain crops per unit is not only an important indicator of food security,but also an important embodiment of scientific and technological progress.This study compares the changing trends of yield on rice,wheat and maize between China and the major crop producing countries during the past 60 years.The Tornqvist index method was used to measure the changes in total factor productivi-ty and input-output index was used to analyze the reasons of the changes in yield of rice,wheat and maize yields in China.The results show that since the reform and opening up,China's yields of major grains have shown different trends in growth compared with those of developed countries,and that this difference is related to differences in the government's R&D system and the adoption of new technologies.China has not adopted genetically modified(GM)maize technology in time further widened the maize yield differ-ence with the United States.Compared with hybird wheat varieties——the intellectual property rights of which are hard to protect,the seed companies,dominated by multinational corporations(MNC),invested more on the development of hybird maize varieties(intellectual property rights are easier to protect).As a result,the wheat yield per unit area in the United States increases more slowly than that of China.The commercial production of GM maize in the United States and Brazil has widened the yield gap between the countries that have not approved GM technology.The total factor productivity per unit of the three crops increased the fastest in wheat and the slowest in maize.The increase of the three crops yield is char-acterized by labor saving and capital substitution of labor.
food securityPer unit yieldinternational comparisontotal factor productivitygenetically modified
万方数据
维普
