Change of Cultivated Land and Its Implications on Food Security in China

The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementation of the ＂Conversion of Cropland to Forest or Grassland＂ project make this situation even worse in China. Thus, there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China. Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results, this paper constructs quality index of cultivated land according to different land quality. Regression models are adopted to predicate changes of main factors from 2004 to 2030, which have great effect on cultivated land area or grain productivity, and verify accuracy with coc^cient of determination （R2）. Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita. There results show that China＇s food supply can only be maintained at a low to middle level of 370-410kg per capita, that is, China has enough land productivity to meet primary demand of food independently. However, it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works, when the grain self-sufficiency maintains no less than 80%. To breed productive crops and to improve land productivity by mefiorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply. The results may offer helpful information for the formulation of policies on population growth, land use, protection of cultivated land.

Scenario-based assessment of future food security

This paper presents a scenario-based assessment of global future food security. To do that,the socio-economic and climate change scenarios were defined for the future and were linked to an integrated modeling framework. The crop yields simulated by the GIS-based Environmental Policy Integrated Climate （EPIC） model and crop areas simulated by the crop choice decision model were combined to calculate the total food production and per capita food availability,which was used to represent the status of food availability and stability. The per capita Gross Domestic Product （GDP） simulated by IFPSIM model was used to reflect the situation of food accessibility and affordability. Based on these two indicators,the future food security status was assessed at a global scale over a period of approximately 20 years,starting from the year 2000. The results show that certain regions such as South Asia and most African countries will likely remain hotspots of food insecurity in the future as both the per capita food availability and the capacity of being able to import food will decrease between 2000 and 2020. Low food production associated with poverty is the determining factor to starvation in these regions,and more efforts are needed to combat hunger in terms of future actions. Other regions such as China,most Eastern European countries and most South American countries where there is an increase in per capita food availability or an increase in the capacity to import food between 2000 and 2020 might be able to improve their food security situation.