Estimation of Land Production and Its Response to Cultivated Land Conversion in North China Plain

Key words: 
• land productivity /
• land production /
• cultivated land /
• cultivated land conversion /
• North China Plain

Abstract:  Food safety and its related influencing factors in China are the hot research topics currently, and cultivated land conversion is
one of the significant factors influencing food safety in China. Taking the North China Plain as the study area, this paper examines the
changes of cultivated land area using satellite images, estimates land productivity from 1985 to 2005 using the model of Estimation
System for Land Productivity (ESLP), and analyzes the impact of cultivated land conversion on the land production. Compared with the
grain yield data from statistical yearbooks, the results indicate that ESLP model is an effective tool for estimating land productivity. Land
productivity in the North China Plain showed a slight decreasing trend from 1985 to 2005, spatially, increased from the north to the south
gradually, and the net changes varied in different areas. Cultivated land area recorded a marginal decrease of 8.0 × 105 ha, mainly
converted to other land uses. Cultivated land conversion had more significant negative impacts on land production than land productivity
did. Land production decreased by about 6.48 × 106 t caused by cultivated land conversion between 1985 and 2005, accounting for
91.9% of the total land production reduction. Although the land productivity increased in Anhui and Jiangsu provinces, it can not offset
the overall adverse effects caused by cultivated land conversion. Therefore, there are significant meanings to control the cultivated land
conversion and improve the land productivity for ensuring the land production in the North China Plain.