Study On Biogas Development And Comprehensive Utiliazation In Rural Area Of Longdong Plateau Of Gansu Province

Xifeng district in Longdong plateau of Gansu Province is a rainfed farming region with comparatively fragile ecological environment and energy shortage. The average available energy per farm household on whole district is only 3284 kilocalories per day, accounts for 57% of actual requirement, annual energy shortage time is 5.4 months (163 days). This paper based on analysis of natural agricultural climatic conditions and current energy supply situation of Xifeng district, the technology of biogas development and comprehensive utilization were studied systematically. The progress and conclusions of the study are as follows:1. The restriction factors of biogas development and utilization in rural area of Xifeng were analyzed, and the countermeasures and suggestions have been proposed. Based on comments of principle and conditions of biogas production and patterns of rural biogas eco-agriculture of China, the model distribution suggestions of farm household biogas production in Xifeng district were proposed, i.e. the undeveloped hilly and gully area should lay emphasis on the model of " combining by three-in-one "; The vegetables production of suburb area should pay attention on the model of " four-in-one "; The orchard area should lay emphasis on the model that " five forms a complete set"; Vegetables, fruit and animal raising combing area should pay attention on the model of" animal-biogas pond-fruit (or vegetable)2. Study on "two steps mixture biogas pool " localization have been carried out, and adaptable technological criterions of biogas pool build, operation and management in Longdong plateau of Gansu Province have been summarized, This laid technological guarantee foundation for instructing biogas extension of local area. The ability of animal husbandry, benefit, labor force status, biogas potential productivity of Xifeng district should be considered when biogas pool capacity is chosen. The suitable biogas pool capacity of the region is 10-15 m~3. The best structure and scale of animal raising for a farm household to produce biogas is "1 cattle + 5 pigs + other little domestic animal (poultries)", or "2 cattle +3 pigs + other little domestic animal (poultries) ", or "3 cattle + other little domestic animal (poultries)", or "7 pigs + other little domestic animal (poultries)".3. The experiment of fluid and mud of biogas pool, which are byproducts of biogasproduction, used as fertilizer on field crop and apple tree have been conducted. The results of the experiment indicated that the fluid and mud of biogas pool can increase the output in various degrees on different crops; it is superior to same type of composts or chemical fertilizers, and it is good for improving quality of crop products. Meanwhile, it can enhance anti-disease ability of crop and decrease cost of chemicals, so it is an ecological safety, labor-saving, money-saving and simple yield increase measures.4. The comprehensive benefit of different ecological models has analyzed, several kinds of different ecological models have different benefits , and all biogas eco-agriculture models has obtained five good effects, i.e. energy benefits, economic benefits, ecological benefits, social benefits and sanitation benefits. Combining with 5 years work experiences of technology extension on rural biogas development and utilization, 7 points of the work experiences in region have been summarized. This laid theoretical foundation for local area and is beneficial reference to other district.