Renewable resource for agricultural ecosystem in China: Ecological benefit for biogas by-product for planting

In China, renewable resources have attracted rising concerns in the sustainable development of circular agricultural economy because renewable resources are considered as a clean energy source and substitutes for chemical fertilizer in rural areas. However, a comprehensive analysis on renewable resources' effect on agricultural ecosystem is still absent. To fill the blank, this paper chose two typical planting-soil ecosystems including greenhouse-soil ecosystem and orchard-soil ecosystem to evaluate the amount of nonrenewable energy (NE) saving, ecological benefits and economic benefits by utilizing biogas fertilizer, in comparison to those by using chemical fertilizer. The results show that compared with chemical fertilizer treatment, in the greenhouse-soil ecosystem, the biogas fertilizer treatment can save 82667.18 MJ NE per hectare, reduce 6554.12 kg carbon dioxide (CO2) emission per hectare, improve soil fertility (soil organic matter, ammonia nitrogen, available phosphorus and available potassium), enhance plant quality (dry matter, solid content, reduced sugar, VC and soluble protein content), increase plant yield and add to 59,232.5 Yuan net income per hectare. We also found out that the optimum ratio of irrigation water and biogas fertilizer is water irrigated with 50% biogas slurry, which can lead to best fruit yield and quality in the orchard-soil ecosystem. It is concluded that promotion of biogas fertilizer can help China to realize low-carbon circular development of agriculture.