碳氮比对有机肥发酵过程中理化性质的影响

Effects of Different C / N on Physical and Chemical Properties of Organic Fertilizer during the Fermentation Process

以玉米秸秆和牛粪为原料,按照不同C/N（20∶1、25∶1、30∶1和35∶1）分层堆积进行有氧发酵,研究不同物料碳氮比（C/N）对有机肥发酵过程中理化性质的影响,以寻找最佳物料C/N.结果表明,不同C/N处理在发酵0～7 d为升温期,8～20 d为高温期,21～30 d为降温期,之后趋于稳定;高于50℃和55℃的时间以C/N为25∶1处理的较长,C/N为30∶1处理的时间最短.各处理在各发酵阶段的氧气浓度供给充足.不同C/N处理发酵堆体积、C/N、有机质含量在发酵阶段总体上均呈下降趋势,总N含量呈上升趋势,各指标均在发酵30d内变化较大.发酵结束后,C/N高的发酵堆体积缩减较多,成品率低;C/N为20∶1、25∶1、30∶1处理的N含量接近;C/N越小,K2O含量越高;P2O5含量、pH各处理间差异较小;各处理在发酵120 d后均达到充分腐熟.4个不同碳氮比处理所产有机肥均达到NY 525-2012要求.综上可知,以牛粪和玉米秸秆作为主要发酵物料,C/N在（20～35）∶1范围内可灵活配比,以选择C/N为25∶1（玉米秸秆与牛粪干物质质量比为6∶4）效果最好.

Corn straw and cow dung were mixed and piled up in layers in accordance with the different C/N （20∶1,25∶1,30∶1 and 35∶1） for aerobic fermentation.The effects of different C/N on physical and chemical properties of organic fertilizer during fermentation process was studied to explore the best material C/N.The results showed that 0 to 7dws was period of heating up,8 to 20 dws was period of high temperature and 21 to 30 days was period of cooling.Then it tended to be stable after piling of different treatment.Days of pile temperature higher than 50 ℃ and 55 ℃ in 25∶1 was the most,30∶1 was the least.Oxygen concentration was inversely related with the change of temperature.Oxygen concentration was lowest in high temperature period.The volume,total N,organic matter of different treatment showed trend of decreaseing.Total N showed an increasing trend with the change greatly within 30 dws.The higher C/N,the more volume reduction and the lower finished product rate.A slightly higher N content was in the 20∶1～30∶1.The smaller C/N,the higher K content.The differenees of pH and P2O5 of different treatment were small.Organic fertilizer reached full maturity after 120 dws.Organic fertilizer of material C/N in the range of 20∶1～35∶1 reached NY 525 2012 requirements.The cow dung and corn straw can be flexibly mixed of material C/N in the range of 20∶1～35∶1.The effecr reached the best when C/N 25∶1 （corn stalk：cow dung as 6∶4was chosen）.