Chen Songhe, Xiang Xiaoling, Ma Hongliang, Penttinen Petri, Zhao Jiarong, Li Han, Gao Rencai, Zheng Ting, Fan Gaoqiong
Key Laboratory of Crop Eco-Physiology and farming system in Southwest China, Ministry of Agriculture, College of Agronomy, Sichuan Agricultural University, Chengdu, China.
Department of Microbiology College of Resources, Sichuan Agricultural University, Chengdu, China.
Front Microbiol. 2021 May 21;12:658668. doi: 10.3389/fmicb.2021.658668. eCollection 2021.
Diazotrophs that carry out the biological fixation of atmospheric dinitrogen (N) replenish biologically available nitrogen (N) in soil and are influenced by the input of inorganic and organic substrates. To date, little is known about the effects of combined organic substrate addition and N fertilization on the diazotroph community composition and structure in purple soils. We investigated the effects of N fertilization and straw mulching on diazotroph communities by quantifying and sequencing the gene in wheat rhizosphere. The abundance and richness of diazotrophs were greater the higher the fertilization level in the mulched treatments, whereas in the nonmulched treatments (NSMs), richness was lowest with the highest N fertilization level. The abundance and α-diversity of diazotrophs correlated with most of the soil properties but not with pH. At the genus level, the relative abundances of , , and were higher in the NSMs and those of , , , , , , , and in the mulched treatments. The differences in community composition between the mulched and the NSMs were associated with differences in soil temperature and soil organic carbon and available potassium contents and C:N ratio. Overall, straw mulching and N fertilization were associated with changes in diazotroph community composition and higher abundance of gene in alkaline purple soils.
进行大气中二氮（N）生物固定的固氮菌会补充土壤中生物可利用的氮（N），并受到无机和有机底物输入的影响。迄今为止，关于添加有机底物和氮肥对紫色土中固氮菌群落组成和结构的影响知之甚少。我们通过对小麦根际的 基因进行定量和测序，研究了施肥和秸秆覆盖对固氮菌群落的影响。在覆盖处理中，施肥水平越高，固氮菌的丰度和丰富度越高，而在未覆盖处理（NSMs）中，氮肥施用量最高时丰富度最低。固氮菌的丰度和α多样性与大多数土壤性质相关，但与pH无关。在属水平上，NSMs中 、 和 的相对丰度较高，而在覆盖处理中 、 、 、 、 、 、 和 的相对丰度较高。覆盖处理和NSMs之间的群落组成差异与土壤温度、土壤有机碳、速效钾含量和碳氮比的差异有关。总体而言，秸秆覆盖和施肥与碱性紫色土中固氮菌群落组成的变化以及 基因的较高丰度有关。
