北方庭院生态农业工程模式及效益分析

庭院生态农业工程模式是通过沼气池发酵，使系统内的物质、能量实现多层次转化，集约利用，把各个子系统的功能转换作为系统的纽带，使生产者、消费者、还原者三个系统密切结合，取得显著的经济、生态和社会效益。庭院生态农业工程模式年经济效益可达近万元，光合作用效率、同化效率、生物质能利用效率、土地资源利用效率均提高，直辖市单纯大棚种菜与单纯大棚养猪的矛盾，科学地解决了北方沼气池越冬问题，沼渣、沼液回田，改良土壤，再生能源，美化环境，该模式适于北方推广。

Courtyard Ecoagricultural Engineering Model and Its Beneficial Results in North China

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.