微生物促腐剂配施固氮蓝藻对水稻秸秆腐解的影响

Effects of microbial promoting-decomposing agent combined with fixing-nitrogen cyanobacteria on rice straw decomposition

【目的】对比6种市售促腐剂降解水稻秸秆的效果,并探究在不同促腐剂中添加固氮蓝藻是否有利于水稻秸秆腐解,为加快还田过程中秸秆腐解速率及推动秸秆的合理化利用提供理论参考。【方法】利用平板培养法,设14组处理,分别为不加菌剂(CK0)、添加固氮蓝藻(CK1)、6种促腐剂及与其对应的添加固氮蓝藻处理,在培养箱中连续培养35 d,每7 d测定一次秸秆失重率、纤维素酶活性、纤维素和半纤维素降解率,并记录秸秆颜色的变化情况。【结果】随着培养时间的延长,秸秆颜色逐渐加深。6种促腐剂均能促进水稻秸秆的腐解,培养至第35 d时,配施豫启富秸秆发酵菌并添加固氮蓝藻(QF+L)处理的秸秆失重率最高,达30.09%,较单独配施豫启富秸秆发酵菌(QF)处理提高13.23%(绝对值),其次为配施周天秸秆腐熟剂并添加固氮蓝藻(ZT+L)和配施益加益粪便除臭发酵菌液并添加固氮蓝藻(YJY+L)处理,失重率分别为29.00%和28.87%,三者间差异不显著(P>0.05),但均显著高于其他处理(P<0.05)。QF+L处理的纤维素酶活性和半纤维素降解率也在培养第35 d时达最高值,分别为27.41 U和28.99%。培养至第35 d时,YJY+L处理的纤维素降解率达最高,为32.19%,且YJY+L处理的纤维素降解率在整个培养过程中均高于单独配施益加益粪便除臭发酵菌液(YJY)处理。相关性分析结果表明,失重率与纤维素和半纤维素降解率均呈极显著正相关(P<0.01),即纤维素和半纤维素降解是导致水稻秸秆失重率上升的重要因素。【结论】在平板培养过程中豫启富秸秆发酵菌和益加益粪便除臭发酵菌液是较好的促腐剂,且添加固氮蓝藻能促进促腐剂腐解水稻秸秆。

【Objective】The aim of the study was to compare the degradation effects of six kinds of microbial promoting-decomposing agent on rice straw,and to explore whether nitrogen-fixing cyanobacteria could improve the ability of the promoting-decomposing agent to decompose rice straw,to provide theoretical reference for accelerating the rate of straw decomposition during the process of returning to the field and promoting the rational utilization of straw.【Method】In this paper,14 groups of treatments were designed with plate culture method in the incubator for 35 d,these treatments included treatment without adding bacteria(CK0),adding nitrogen-fixing cyanobacteria(CK1),six kinds of promotingdecomposing agents and corresponding promoting-decomposing agents with nitrogen-fixing cyanobacteria.The weight loss rate of rice straw,cellulase activity,cellulose and hemicellulose degradation rate were measured every 7 d,and the color variation of rice straw was recorded.【Result】The results showed that the color of the rice straw gradually deepened with the development of the cultivation time,each of the promoting-decomposing agent could promote the degradation of rice straw.The weight loss rate of rice straw treated by Yuqifu straw fermentation strain+nitrogen-fixing cyanobacteria(QF+L)was up to 30.09%at the 35th d,which was 13.23%(absolute value)higher than that of Yuqifu straw fermentation strain only(QF).Followed by treatment Zhoutian straw decomposing agent with nitrogen-fixing cyanobacteria(ZT+L)and adding Yijiayi manure deodorizing fermentation bacterial liquid with nitrogen-fixing cyanobacteria(YJY+L),their weight loss rates were 29.00%and 28.87%,respectively.There was no significant difference among the three treatments(P>0.05),but they were significantly higher than other treatments(P<0.05).The cellulase activity and hemicellulose degradation rate of QF+L treatment also reached the highest values at the 35thd,which were 27.41 U and 28.99%,respectively.At the 35thd,the cellulose degradation rate of YJY+L treatment reached the highest value(32.19%),and the cellulose degradation rate of YJY+L treatment was higher than that of manure detoxification fermentation liquid(YJY)alone in the whole culture process.Correlation analysis showed that,there were extremely positive correlation between weight loss rate and degradation rate of cellulose and hemicellulose(P<0.01),the degradation rate of cellulose and hemicellulose were important factors leading to the increase of weight loss rate of rice straw.【Conclusion】Based on the results of this experiment,Yuqifu and Yijiayi are better promoting-decomposing agent in the plate culture process,and the nitrogenfixing cyanobacteria can improve the ability of promoting-decomposing agent to decompose rice straw.