Survey Of Main Organic Fertilizer Resources In Guangxi And Rapid Composting Of Silkworm Excrement

Application of organic fertilizer is the efficient way to solve the problems such as the decline of land productivity and environmental pollution in China rural areas. In this study, by analyzing the data from Guangxi Statistical Yearbook during2005to2010and field investigation, it was found that there are major problems for the utilization of the organic fertilizer resources, including low utilization rate, low industrialization rate and the difficulties in popularized utilization. The following suggestions were advanced to solve the problems including (1) to develop industrialization of organic fertilizer by improving techniques and increasing financial and policy supports,(2) to strengthen propaganda efforts for the popularization of the utilization of organic fertilizer,(3) to build more infrastructures for the composting of organic fertilizer and (4) to enhance the recycling and reuse of rural wastes and so on.The rapid composting of silkworm excrement not only reduces the pollution of the silkworms to the silkworm field, but also utilizes the silkworm excrement as fertilizer for mulberry. In this study, four batches of aerobic fermentation experiments at high temperature were carried out after mixing the excrement from silkworm at the4th or5th age with appropriate proportion of accessory materials and seven fermentation agents. No.1to No.5agents were microbial agents, No.6and No.7fermentation agents were agents with cellulose degradation enzymes. Results show that adding No.1agent mixed with No.6or No.7agent (combination of best microbial agent and the agent with cellulose degradation enzymes) shortened the fermentation time from more than6months to10days, and silkworm excrement: fermentation agent:accessory material is1000:1:5. And all indexes in the silkworm excrement compost were in accordance with the national standard for the organic fertilizer. The organic matter was>30%, total N+total P2O5+total K2O>4.0%, C/N<20:1and pH5.5-8.0, respectively. The results suggest that aerobic fermentation at high temperature is an affective technology for fast composing of the silkworm excrement as organic fertilizer resources by adding appropriate proportion of accessories and fermentation agent.