[Dynamic of carbon footprint and its composition for double rice production in Southern China during 2004-2014]

The area of rice production in Southern China is one of the most important farming regions in China, due to its great contribution to national food security. To assess the differences in carbon footprints (CF) of double rice production will benefit the achievement of low carbon agriculture. Base on the statistical data of crop yield and farmland investment of double rice production from 2004 to 2014, the spatiotemporal dynamics of CF and its composition of double rice in Southern China was estimated using the theory of CF and life cycle assessment method. The results showed that the CF of early and late rice in each province tended to increase, with the CF of early rice being higher than that of late rice. CF of early and late rice in Anhui were the highest (1000 kg CO₂-eq·hm^-2), and those in Fujian, Hubei and Hunan were the lowest (750 kg CO₂-eq·hm^-2). The highest component of CF in double rice was the production, transportation and utilization of fertilizers (60%), followed with the consumption of diesel. Progressive regression analysis showed that CF of double rice from 2004 to 2014 was mainly affected by diesel, compound fertilizer and K₂O fertilizer. The analysis of net profit income showed that Hubei was a province with low-emission and high-yield, which was conducive to the sustainable development of low carbon agriculture. Given to the large transfer of rural labor from agricultural to non-agricultural sections and the development of mechanization, diesel and other mechanical inputs would increase rapidly in the future. Therefore, improving fertilizer utilization, mechanical and irrigation efficiencies in crop production would be the main approach to promote low-carbon agriculture in rice production of southern China.