Courtyard Ecoagricultural Engineering Model and Its Beneficial Results in North China
北方庭院生态农业工程模式及效益分析

Courtyard eco-agro-engineering model is by generating marsh gas to multi-grade utilization of materials and energy,turn the functions of each subsystem into the linkage of the model,and combine the three systems of producer,consumer and restorer to achieve high economic,ecological and social beneficial results.The annual economic results of this model was aboout 10,000 yuan,light utilization rate,assimilation and bio-energy utilization were increased.This model can solve the problems in combination of vegetable planting and pig raising using greenhouses as well as generating marsh gas in winter.In this model the residues from generating boigas were returned to farmland,then soil fertility was increased.