不同辅料对蚕沙堆肥的影响

Impacts of various materials on composting of silkworm excrement

【目的】实现蚕沙的无害化处理和资源化利用。【方法】以新鲜蚕沙为原料分别按质量比添加5.21%熟石灰、0.20%EM菌剂和10%桑枝屑,以未添加任何物质的新鲜蚕沙为对照,制定4种好氧堆肥体系,分析堆肥过程中的理化指标及微生物菌落数量的动态变化。【结果】添加5.21%的熟石灰使堆体温度升至50℃的时间比对照推迟了5 d,堆体pH比有机肥标准高1.05,细菌菌落数减少,但有利于真菌和放线菌的繁殖,使堆体有机质含量下降、全氮量增加和含水率下降显著。添加0.20%EM菌剂,使全磷含量比对照增加了28%,有利于提高细菌菌落数,但真菌在堆肥中、后期的繁殖受影响,放线菌在整个堆肥期繁殖都受影响,其他指标的变化与对照差别不大。添加10%桑枝屑能使堆体含水率比对照降低40%,造成温度偏高而不利于真菌和放线菌的繁殖,其碳氮比的下降亦显著低于其他堆体,同时会造成堆体pH高0.66。4个堆体发芽指数均超过100%;堆体在50℃以上持续的时间均超过7 d。【结论】经堆肥处理后,4个堆体均可以使蚕沙达到资源化利用的要求。

[ Objective] To acheive the innocuous treatment and resource utilization of silkworm excre- ment. [ Method] Fresh silkworm excrement pile was mixed with 5.21% hydrated lime, 0.20% EM agent, or 10% mulberry sawdust in mass fraction. The silkworm excrement pile without any addition served as the control. These four different aerobic composting systems were used for investigating the dy- namic changes of physicochemical indexes and population of microbial flora during the composting process. [ Result] The treatment with 5.21% hydrated lime,facilitated the reproduction of fungi and acti- nomycetes, decreased the organic matter content and the moisture content of the pile, increased the total nitrogen content of the pile, delayed 5 d before the temperature of the pile heating up to 50 ~C, resulted in 1.05 higher pH compared to the organic fertilizer standard, and decreased the number of bacterial col- onies. The treatment with EM improved the total phosphorus content by 28 %, which increased the num- ber of bacterial colonies, but negatively affected the reproduction of fungi in the middle and later periods and the reproduction of actinomycetes throughout the composting process. No significant differences of other indicators were observed between the treatment with 0. 20% EM and the control. The treatment with 10% mulberry sawdust reduced the moisture content by 40% , led to higher temperature which was disad- vantageous for the reproduction of fungi and actinomycetes, and caused a significantly lower C/N ratio and 0. 66 higher pH of the pile compared to other treatments. Germination indexes of four piles were a- bove 100% , and all pile temperatures kept above 50℃ for more than 7 d. [ Conclusion] All four piles of silkworm excrement can meet the demand of resource utilization after composting.