玉米秸秆不同腐解处理还田对黑土碳氮比的影响研究

Effects of Different Maize Straw Returning Modes on C/N Ratios in Mollisol

以东北黑土农田生态系统为研究对象,玉米秸秆配施不同处理的菌剂为还田材料,通过田间试验,探讨在不同菌剂处理方式下,秸秆还田后对土壤碳氮比的影响。结果表明,BNB处理对秸秆的腐熟有显著的促进作用,BNF处理、BB处理与BNB处理可以有效提高土壤可溶性有机碳氮比,说明无论是菌剂、腐熟菌剂还是表面活性剂均可有效提高黑土土壤可溶性有机碳氮比。2011年与2010年相比,秸秆不同腐解处理还田在提高土壤有机质含量的同时,可能更有利于提高土壤全氮的含量,从而导致土壤C/N值的降低。并且能够有效提高土壤微生物C/N,有利于提高土壤供肥水平。

In order to study the effects of straw returning modes with different microbial inoculum on soil C/N ratios in Mollisol, a field experiment was carried out in farmland ecological system in the Northeast China. And the maize straw combined with application of microbial agent was selected as returning materials. The results showed that the BNB agent could significantly promote straw decomposition. BNF, BB and BNB agents could effectively improve the soil soluble C/N. By comparison of 2011 and 2010, we found that different treatments improved soil organic matter contents; at the same time, they could also be more effective in improving soil total nitrogen content, thus resulted in the reduction of soil C/N ratio. And each treatment could effectively improve the soil microbial C/N and therefore enhanced soil fertility. This study elaborated no matter whether the microbial inoculum was un-rotten species or rotten species or surface active agents, they could all effectively improve soil soluble C/N ratios in the Mollisol. These treatments could also improve the activities of urease and catalase in the Mollisol.