Cultivated Land Changes and Agricultural Potential Productivity in Mainland China

With rapid and continuous population growth and the associated declining quality of cultivated land, food security in China has been attracting the attention of scholars both domestically and internationally. In recent decades, the implications of the cultivated land balance policy have promoted spatial changes of cultivated land. Estimating the agricultural potential productivity and assessing its response to cultivated land changes could provide a scientific basis for strategic decision-making concerning grain production and thus guarantee food security. In the present study, the Agro-Ecological Zone (AEZ) model was applied to estimate the agricultural potential productivity. Data from the second national land survey were first applied to characterize the changes of cultivated land (by comparing the cultivated land in 2009 with that in 2012) and their influence on potential productivity in Mainland China. We propose a utilization degree of total potential productivity (UTP) and its ratio coefficient (RUTP) to reveal the utilization status of potential productivity and its change characteristics at the provincial level. It was found that there was a trend for cultivated land to be shifted away from cities, and the average productive capability per hectare of cultivated land declined from 7386.5 kg/ha to 6955.2 kg/ha by occupying highly productive cultivated land generally near the cities and compensating less productive cultivated land in remote areas. UTPs and RUTPs indicate a significant difference in the utilization status of potential productivity among the 31 provinces of Mainland China. Grain production with the aim of sustainable development should be strategized according to the particular facts of each province. The methods we applied can mine the impacts of cultivated land changes on potential productivity and the utilization of potential productivity effectively.