Spatial-temporal distribution of biogas production from agricultural waste per capita in rural China and its correlation with ground temperature.

Biogas production from agricultural waste has played a key role in recent years in reducing the environmental pollution risk of agricultural waste and alleviating energy shortage in rural China. However, few studies have focused on the effect of ground temperature on biogas production from agricultural waste from a quantitative point of view and the solution to increasing the temperature of biogas digesters in the cold season to improve biogas production from agricultural waste in rural areas at a provincial scale. Here, we calculated the spatial-temporal distribution of biogas production from agricultural waste per capita in rural China from 2001 to 2016 and agricultural waste per capita in rural China in 2016. Furthermore, we analyzed the correlation between biogas production from agricultural waste per capita in rural China and ground temperature. Finally, we proposed a solution to increase the temperature of biogas digesters in rural China in the cold season after analyzing its energy utilization. Results showed that the biogas production from agricultural waste per capita in rural China was correlated with the average and maximum ground temperature in January, February, March, November, and December from 2001 to 2016. The results also indicated that the suggested heating mode of biogas production from agricultural waste in rural China differed greatly among provinces. The provinces with high agricultural waste per capita in rural areas and low averaged biogas production from agricultural waste per capita are Inner Mongolia, Heilongjiang, and Xinjiang, which needed the suggested heating mode of biogas production from agricultural waste for increasing the temperature of biogas digesters in rural China in the cold season. Our findings provide a reference for biogas production from agricultural waste, greenhouse gas emission reduction, and the spatial layout of energy utilization in rural China.