强还原处理所使用有机物料与其杀菌效果的相互关系

Relationships between different types of organic matters and disinfestation effects during reductive soil disinfestation

创造土壤厌氧环境并添加大量有机物料的强还原处理(reductive soil disinfestation,RSD)是一种有效的土壤消毒方法,但对于RSD过程中添加不同有机物料与其杀菌效果间的相互关系研究甚少。本试验采集两种连作土壤,分别进行添加稻壳(RSD1)、麦麸(RSD2)和芦苇(RSD3);甘蔗渣(RSD4)、葡萄糖(RSD5)和纤维素(RSD6)的RSD处理,采用荧光定量PCR、变性梯度凝胶电泳等方法研究物料理化性质与杀菌效果的相互关系。结果表明:RSD处理显著地降低了土壤中的NO-3-N含量和电导率Ec,增加了NH+4-N含量;稻壳、麦麸和芦苇RSD处理的杀菌效果分别为88.60%、90.76%和85.91%,甘蔗渣、葡萄糖和纤维素RSD处理的杀菌效果分别为72.30%、85.87%和30.65%;有机物料中的总有机碳(total organic carbon,TOC)、易氧化有机碳(easily oxidized organic carbon,EOC)和总氮(total nitrogen,TN)与杀菌效果及细菌数量都呈显著正相关(P<0.05),土壤中添加有机物料初始C/N与杀菌效果呈显著负相关,与细菌数量显著正相关。综上所述,添加高EOC和TN及低C/N的有机物料的RSD处理杀菌效果更好。

Although reductive soil disinfestation（RSD）through creating anaerobic condition and incorporating soil with large amounts of organic matters is an effective method for soil disinfestation,there is limited information about the relationships between the type of organic matter and disinfestation effects（DEs）.Hence,in this study,various RSD treatments incorporated with rice hull（RSD1）,wheat bran（RSD2）,and reed（RSD3）,sugarcane residue（RSD4）,glucose（RSD5）,and cellulose（RSD6）were respectively conducted,and quantitative real-time PCR and denaturing gradient gel electrophoresis（DGGE）were performed to investigate the relationships between organic matters and DEs.The results showed that the content of soil NO-3-N and electrical conductivity（Ec）significantly decreased in the RSD treatments,whereas the content of NH＋4-N significantly increased.The DEs of these RSD treatments（RSD1-6）were 88.60%,90.76%,85.91%,72.3%,85.87%,and 30.65%,respectively.Total organic carbon（TOC）,easily oxidized organic carbon（EOC）,and total nitrogen（TN）in the organic matter had a significant positive correlation with DE and bacterial population（P〈0.05）.Besides,the in-itial soil C/N after incorporating the organic matters had a significant negative correlation with DE,and had a significant positive correlation with bacterial population.Therefore,the RSD treatments incorporated with the organic matters with higher EOC,TN and lower C/N would obtain a better disinfestation effect.