论文部分内容阅读
【目的】对比设施菜田与棚外粮田土壤菌群以及N2O产生模式的差异。【方法】采用变性梯度凝胶电泳(DGGE)和反硝化功能基因(nir S,nos Z)方法分别比较两种土壤细菌群落以及功能基因类群丰度的差异,利用自动连续在线培养监测体系(Robot系统)测定两种土壤在好氧、厌氧阶段N2O等反硝化相关气态产物产生模式,分析N2O/(N2+N2O+NO)产物比。【结果】设施菜田与棚外粮田具有不同的土壤细菌群落结构,并且土壤细菌总量得到了显著的提升,然而两种反硝化功能基因(nir S,nos Z)丰度并没有显著变化。与设施菜田相比,棚外粮田有相对低的N2O积累量以及产物比,并且在厌氧初期气体产生模式有所不同。培养后铵态氮和亚硝态氮含量上升。【结论】设施菜田长期有别于棚外粮田的管理方式造成了土壤细菌群落的显著改变,增大了活跃微生物总量,造成土壤酸化,并导致N2O在气态产物中的比例升高。设施菜田土壤微生物进行了与棚外粮田不同的硝酸盐呼吸过程,异化硝酸盐还原成铵(DNRA)过程有可能贡献了两种土壤的部分厌氧N2O产生量。
【Objective】 The purpose of this study was to compare the differences in soil microbial communities and N2O production patterns between vegetable fields and outside grain fields. 【Method】 The differences of bacterial community and abundance of functional gene groups in two soil samples were compared by denaturing gradient gel electrophoresis (DGGE) and denitrifying functional gene (nir S, nos Z), respectively. The automated continuous online culture monitoring system System) was used to determine the production patterns of N2O and other denitrification-related gaseous products in aerobic and anaerobic stages. The product ratio of N2O / (N2 + N2O + NO) was analyzed. 【Result】 The results showed that there was a different soil bacterial community structure between the vegetable field and the grain field outside the greenhouse, and the total amount of soil bacteria was significantly increased. However, the abundance of the two denitrification genes (nir S, nos Z) did not change significantly . Compared with the vegetable fields in the facilities, the crop fields outside the greenhouse had relatively low N2O accumulation and product ratio, and gas generation patterns differed in the early stages of anaerobic. Ammonium and nitrite nitrogen levels increased after culture. 【Conclusion】 The long-term different management methods of vegetable fields from the shed grain fields resulted in significant changes in soil bacterial communities, increased the total amount of active microorganisms, caused soil acidification and led to an increase in the proportion of N2O in gaseous products. The soil microorganisms in the vegetable field had different nitrate respiration processes from the grain fields outside the greenhouse, and the process of reducing nitrate to ammonium (DNRA) might contribute to the partial anaerobic N2O production in both soils.