Energy analysis on planting-breeding circulating agriculture ecosystem linked by biogas

Based on combining biogas engineering with planting, constructing circular agriculture model including planting and culture linked by biogas project is used to dealing with pig slurry at present. Taking model Ⅰ(system with only pig-breeding )as a reference, cycle agricultural system of livestock farm in Xingyuan Fuqing (the modelⅡ)was evaluated using energy theory. Results indicated that whole benefit of the modelⅡ was better than the the modelⅠ; Compared with the modelⅠ, the modelⅡ decreased environmental loading ratio by 15.00%, increased sustainable development index by 15.71% and increased economic benefits by 18.96%, however slightly lowered at production efficiency. It was concluded that the modelⅡ realized the aim that "reduction of resource, material recycling and reuse", and then eco-efficiency and economic benefits had been improved. This paper provides a scientific basis for extension of cycle agricultural system with planting and breeding.