菌渣-发酵床废弃垫料堆肥中温室气体排放及与微生物的关系

堆肥是处理农业废弃物最适宜的技术之一,但堆肥产生的有害和温室气体排放导致环境污染问题.本研究以生猪养殖发酵床废弃垫料及菌渣为原料,利用强制通风静态堆肥技术研究垫料和菌渣不同配比及添加EM菌剂对堆肥过程温室气体排放和微生物区系的影响.结果表明,不同堆肥处理温室气体排放通量以堆肥前20 d较大,堆肥中后期降低;微生物总量和种类在不同堆肥处理间没有发生显著性变化;CO_2和N_2O排放速率与细菌、真菌和甲烷氧化菌间具有显著的正相关关系.整个堆肥期间,以菌渣为主料并添加EM菌剂的堆肥处理温室气体减排效果最佳,相对其他3个处理温室气体减排0.7%~10.2%.由此认为,以菌渣为主料和通过添加EM菌剂的堆肥方式可以作为降低菌渣-发酵床废弃垫料堆肥过程温室气体排放的策略.

Greenhouse gas emission and its correlation with microbial in composting of waste packing and fungus chaff

Aerobic composting is an effective way to treat and recycle agricultural waste. However, the aerobic composting is a potential source of the greenhouse gas (GHG) including CO₂, N₂O and CH₄ to the atmosphere, which is closely associated to the global greenhouse effect. Therefore, the control of GHG emission in the process of aerobic composting should be primarily considered. In this study, an experiment was conducted to study GHG emission and its correlation with microbial in composting of waste and fungus chaff by using static forced-air composting boxes. Thereinto, waste packing and fungus chaff were mixed according to the weight ratio (4:6 or 6:4) with or without EM microbial agent addition, respectively. The results show that GHG emission from different composting treatments were larger in the early stage (within 20 days) of composting, and then decreased in later stage of composting. This could probably be explained by the fact that microorganisms rapidly developed in the initial stage of composting. There was not significant difference in microbial quantity and species among different composting treatments. But the correlation analysis shows that the fungi, bacteria and methane oxidizing bacteria had significant positive correlation with CO₂ and N₂O emission rates, especially for bacteria. Comparing with the other three treatments, GHG emissions from the composts with fungus chaff (60% of total) and EM microbial agent addition decreased by 0.7% to 10.2%. It is concluded that the method of composting with fungus chaff as main material supplemented with EM microbial agent could be used to reduce GHG emission during composting of waste packing and fungus chaff.