Comparison Of Current Situation And Effect Of Biogas Utilization In Lin'an District

Agricultural non-point source pollution such as excrements of livestocks are thought to be one of key limiting factors in beautiful countryside construction.Excrements of livestocks contains large amounts of organics,pathogenic microorganism,parasite and heavy metals,and thus decreased the quality of livestocks and further affects the environments.Resourceful disposal of excrements such as biogas fermentation are considered as an effective measurement to resolve the excrements pollution.However,the application of biogas fermentationdifferentiated dependent on the areas,and only a few researches concerned on the effects of biogas slurry on vegetables quality.Thus,the present study investigated the status of resourceful disposal of biogas slurry in Lin'an district of Hangzhou City by document retrieval,and studied the effects of biogas slurry on the fruit quality of corns.The main results were as follows.1.We combed the policies and measures on supporting the resourceful disposal of biogas slurry by Zhejiang Province and Hangzhou City through document retrieval and spot investigation in Lin'an District.Also we summarize the achievements of resourceful disposal of biogas slurry in Lin'an District.These achievements included construction of comprehensive utilization of biogas slurry,improvement of efficiency of utilization,and so on.Besides,we analyzed the economic benefits,the ecological benefit and social benefit as well.The economic benefits were represented by the reduce of cost,which was about 300 Yuan/667 m~2.Furthermore,we abstracted the existing problems during the utilization,such as the safety of biogas slurry,surplus production,and lack of technology supporting.Meanwhile we put forward the development countermeasure,including promotion of research,development of ecological elimination places,strengthen the input of biogas fermentation,and aggrandizing propaganda.2.We investigated the effects of biogas slurry on the quality of corn and sweet potato in field conditions.As to corn,application of biogas slurryincreased the production by 33.3%,increased the water content,Vitamin C,ash and amylose by 33.3%,12.3%,37.5%and 333.1%,respectively,while decreased the content of protein,total starch and sugars by 36.3%,58.8%and 54.5%,respectively.Meanwhile,application of biogas slurryreduced the rind hardness,toughness and flesh hardness.As for sweet potato,application of biogas slurry increased the production by 7.6%,enhanced the water content,Vitamin C and ash by 7.5%,16.2%and 12.5%,respectively,while decreased the content of protein,total starch and sugars by 49.8%,12.2%and 55.6%,respectively.Besides,application of biogas slurryreduced the hardness of both rind and flesh.These results suggested that effects of biogas slurry on fruit quality depended on the variety of vegetables and components.