Influence of initial C/N ratio on chemical and microbial composition during long term composting of straw
Influence of initial C/N ratio on chemical and microbial composition during long term composting of straw
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DOI：
10.1007/s002480000071
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发表时间：
2001-04-01
影响因子：
3.6
通讯作者：
Bååth, E
中科院分区：
文献类型：
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作者：
Eiland, F;Klamer, M;Bååth, E
在800 l箱中添加不同量的猪浆作为氮源，对芒草秸秆碎料进行堆肥处理。在12个月的堆肥过程中，通过检查化学和微生物参数来评估不同初始CIN比（11、35、47、50和54）对堆肥过程和最终产品的影响。较低的初始C/N比率导致堆肥前三个月纤维的快速降解（半纤维素：50-80%，纤维素：40-60%），而较高的初始C/N比率导致半纤维素和纤维素降解10-20%。这些差异反映在微生物生物量和呼吸量上，低碳氮比处理的微生物生物量和呼吸量最初高于高碳氮比处理。经过12个月的堆肥处理，情况发生了逆转。与初始C/N比较低的处理(小于10杯ATP g（-1) OM和25杯CO2 h(-1) OM）相比，高初始CIN比的堆肥具有较高的微生物生物量（15-20杯ATP g(-1) OM）和呼吸速率(200杯CO， h（-1) g(-1) OM）。这可以解释为在高碳氮比处理下微生物受到氮限制。在低碳氮比处理中，不限制氮的情况下，由于易有效碳的耗尽，开始时的高活性随着时间的推移而下降。不同的氮有效性也体现在硝化模式中，因为硝酸盐只有在初始C/N比为11和35的处理中才有显著的量。微生物群落结构（以磷脂脂肪酸、PLFA、剖面测量）也受到初始C/N比率的影响，堆肥12个月后，与高C/N处理相比，低C/N处理的真菌/细菌比率较低。然而，在低C/N处理中，与高C/N处理相比，发现更高水平的PLFAs表明嗜热革兰氏阳性细菌。这是由于低碳氮比处理的初始加热阶段比高碳氮比处理的长。不同的真菌/细菌比例也可以用初始加热阶段来解释，因为这个比例与初始堆肥阶段产生的热量之间存在显著的相关性。
Shredded straw of Miscanthus was composted in 800-L boxes with different amounts of pig slurry added as nitrogen source. The impact of the different initial CIN ratios (11, 35, 47, 50, and 54) on the composting process and the end product was evaluated by examining chemical and microbiological parameters during 12 months of composting. Low initial C/N ratios caused a fast degradation of fibers during the first three months of composting (hemicellulose: 50-80%, cellulose: 40-60%), while high initial C/N ratios resulted in 10-20% degradation of both hemicellulose and cellulose. These differences were reflected in the microbial biomass and respiration, which initially were higher in low C/N treatments than in high C/N treatments. After 12 months of composting, this situation was reversed. Composts with high initial CIN ratios had high microbial biomass (15-20 mug ATP g(-1) OM) and respiration rates (200 mug CO, h(-1) g(-1) OM) compared to treatments with low initial C/N ratios (less than 10 mug ATP g(-1) OM and 25 mug CO2 h(-1) g(-1) OM). This could be explained by the microorganisms being nitrogen limited in the high C/N ratio treatments. In the low C/N ratio treatments, without nitrogen limitation, the high activity in the beginning decreased with time because of exhaustion of easily available carbon. Different nitrogen availability was also seen in the nitrification patterns, since nitrate was only measured in significant amounts in the treatments with initial C/N ratios of 11 and 35. The microbial community structure (measured as phospholipid fatty acid, PLFA, profile) was also affected by the initial C/N ratios, with lower fungal/bacterial ratios in the low compared to the high C/N treatments after 12 months of composting. However, in the low C/N treatments higher levels of PLFAs indicative of thermophilic gram-positive bacteria were found compared to the high C/N treatments. This was caused by the initial heating phase being longer in the low than in the high C/N treatments. The different fungal/bacterial ratios could also be explained by the initial heating phase, since a significant correlation between this ratio and heat generated during the initial composting phase was found.