School of Environmental Science and Engineering, Tianjin University, Weijin Road, Tianjin 300072, China.
School of Environmental Science and Engineering, Tianjin University, Weijin Road, Tianjin 300072, China; College of Natural Science, Arba Minch University, Arba Minch 21, Ethiopia.
Sci Total Environ. 2022 Aug 25;836:155671. doi: 10.1016/j.scitotenv.2022.155671. Epub 2022 May 4.
It is widely thought that organo-mineral complexes (OMCs) stabilize organic matter via mineral adsorption. Recent studies have demonstrated that root exudates can activate OMCs, but the influence of OMCs on plant rhizosphere, which is among the most active areas for microbes, has not been thoroughly researched. In this study, a pot experiment using Brassica napus was conducted to investigate the effects of OMCs on plant rhizosphere. The result showed that OMC addition significantly promoted the growth of B. napus compared to the prevalent fertilization (PF, chemical fertilizer + chicken compost) treatment. Specifically, OMC addition increased the relative abundance (RA) of nitrogen-fixing bacteria and the bacterial α-diversity, and the operational taxonomic unit (OTU) group with RA > 0.5% in the OMC-treated rhizosphere was the result of a deterministic assembly process with homogeneous selection. Gene abundance related to nitrogen cycling and the soil chemical analysis demonstrated that the OMC-altered bacterial community induced nitrogen fixation and converted nitrate to ammonium. The upregulated carbon sequestration pathway genes and the increased soil microbial biomass carbon (23.68%) demonstrated that the bacterial-induced carbon storage in the rhizosphere was activated. This study shows that the addition of OMCs can influence the biogeochemical carbon and nitrogen cycling via regulating microorganisms in the rhizosphere. The findings provide fresh insights into the effects of OMCs on the biogeochemical cycling of important elements and suggest a promising strategy for improving soil productivity.
人们普遍认为有机-矿物复合体（OMC）通过矿物吸附来稳定有机物。最近的研究表明，根分泌物可以激活 OMC，但 OMC 对植物根际的影响，根际是微生物最活跃的区域之一，尚未得到深入研究。在这项使用油菜的盆栽实验中，研究了 OMC 对植物根际的影响。结果表明，与常用施肥（PF，化肥+鸡粪）处理相比，添加 OMC 显著促进了油菜的生长。具体来说，添加 OMC 增加了固氮菌的相对丰度（RA）和细菌α多样性，而 OMC 处理根际中 RA>0.5%的 OTU 组是同质选择的确定性组装过程的结果。与氮循环和土壤化学分析相关的基因丰度表明，OMC 改变的细菌群落诱导了氮固定并将硝酸盐转化为铵。上调的碳固存途径基因和增加的土壤微生物生物量碳（23.68%）表明，细菌诱导的根际碳储存被激活。本研究表明，添加 OMC 可以通过调节根际微生物来影响生物地球化学碳和氮循环。这些发现为 OMC 对重要元素生物地球化学循环的影响提供了新的见解，并为提高土壤生产力提供了一种有前途的策略。
