Spatial shifts in grain production increases in China and implications for food security

China's food security remains a worldwide concern due to its huge population and rapid urbanization. As demonstrated by statistics, China's total grain output has been continuously increasing since 2003. Meanwhile, the grain production growth has shown various spatial disparities across the country. This paper explores the spatial shifts in grain production increase and their potential impacts at county-level in China. The results show that the barycenter of grain production has moved northward obviously and crossed the Yellow River, which served as the main irrigation water source for agriculture in North China. Both absolute grain output growth and relative growth patterns demonstrate that North China, especially the region of north bank of the Yellow River, has been the significant area contributing to grain production. China has shifted grain production to the marginal regions with lower land productivity and higher natural risk. Although China's grain output has increased continuously, the grain output system is now more vulnerable and unstable than before. In the final part, the paper discusses the three main factors influencing the spatial shifts in grain output, which are farmland protection system, farmer-protecting grain subsidy policies and the dramatic improvement in agricultural infrastructure, and gives some suggestions on the improvement of farmland protection system and agricultural support policy.