Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (11): 3039-3059.DOI: 10.1016/S2095-3119(20)63567-5

所属专题: 农业生态环境-土壤微生物合辑Agro-ecosystem & Environment—Soil microbe

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  • 收稿日期:2020-06-11 出版日期:2021-11-01 发布日期:2021-09-17

Linking changes in the soil microbial community to C and N dynamics during crop residue decomposition

Cyrine REZGUI1, Isabelle TRINSOUTROT-GATTIN1, Marie BENOIT2, Karine LAVAL1, Wassila RIAH-ANGLET1
  

  1. 1 AGHYLE Research Unit, UniLaSalle, Rouen-Team, Mont-Saint Aignan 76134, France
    2 Agroecology and Environment Research Unit, Isara, AgroSchool for Life, Lyon 69007, France 
  • Received:2020-06-11 Online:2021-11-01 Published:2021-09-17
  • Contact: Correspondence Wassila RIAH-ANGLET, Tel: +33-2-32829198, E-mail: Wassila.RIAH-ANGLET@unilasalle.fr
  • About author:Cyrine REZGUI, E-mail: Cyrine.Rezgui@unilasalle.fr;
  • Supported by:
    This research was funded by the Normandy region and was supported by the Vivepois Project (D16-12746), France.

摘要:

一方面,中国亚热带红壤区水稻土母质和肥力水平多变;另一方面,细菌多样性和群落组成在土壤生态系统过程和功能中发挥关键作用。但是水稻土的母质和肥力对细菌多样性和群落组成的影响如何仍不清楚,不同母质和肥力水平条件下驱动水稻土细菌多样性、群落组成和特异微生物种群变化的关键因素尚不明确。因此,本研究采集亚热带红壤区具有不同母质(第四纪红黏土或第三纪红砂岩)和不同肥力水平(高肥力或低肥力)的典型样地水稻土样品,通过454高通量测序测定细菌16S rRNA基因的V4−V5区,分析细菌多样性指数和群落组成变化。采用two-way ANOVA和two-way PERMANOVA探明母质和肥力对细菌多样性和群落组成的影响;主坐标分析(PCoA)、冗余分析(RDA)和多元回归树分析(MRT)明确细菌群落的变化,以及驱动该变化的关键土壤因子;共现网络分析阐明属水平特异细菌种群和关键土壤因子的关系;宏基因组差异分析工具(STAMP)确定不同土壤样品间差异物种。结果显示,母质和肥力对水稻土细菌多样性指数变化的贡献相似。但是肥力水平对细菌群落组成的影响要远大于母质。土壤因子,特别是土壤质地与细菌多样性指数密切相关。RDA分析发现土壤有机碳(SOC)是影响细菌群落组成的首要因素,并且25.5 g kg−1有机碳含量是驱动高肥力和低肥力土壤细菌群落组成分异的关键阈值。共现网络分析暗示高肥力水平下,由于土壤环境的改善,细菌趋向于合作关系,并且富营养型细菌占主导地位。STAMP分析发现高肥力水稻土中MassiliaRhodanobacter等富营养型细菌大量富集;而低肥力土壤中Anaerolinea等贫营养型细菌占主导。研究结果表明,不同母质和肥力水稻土中,土壤质地影响细菌多样性指数变化;而养分水平,特别是有机碳水平决定细菌群落组成的变化。


Abstract:

Crop residues are among the main inputs that allow the organic carbon (C) and nutrients to be maintained in agricultural soil.  It is an important management strategy that can improve soil fertility and enhance agricultural productivity.  This work aims to evaluate the extent of the changes that may occur in the soil heterotrophic microbial communities involved in organic matter decomposition and C and nitrogen (N) mineralization after the addition of crop residues.  Soil microcosm experiments were performed at 28°C for 90 days with the addition of three crop residues with contrasting biochemical qualities: pea (Pisum sativum L.), rapeseed (Brassica napus L.), and wheat (Triticum aestivum L.).  Enzyme activities, C and N mineralization, and bacterial and fungal biomasses were monitored, along with the bacterial and fungal community composition, by the high-throughput sequencing of 16S rRNA and ITS genes.  The addition of crop residues caused decreases in β-glucosidase and arylamidase activities and simultaneous enhancement of the C mineralization and net N immobilization, which were linked to changes in the soil microbial communities.  The addition of crop residues decreased the bacterial and fungal biomasses 90 days after treatment and there were shifts in bacterial and fungal diversity at the phyla, order, and genera levels.  Some specific orders and genera were dependent on crop residue type.  For example, Chloroflexales, Inquilinus, Rubricoccus, Clitocybe, and Verticillium were identified in soils with pea residues; whereas Thermoanaerobacterales, Thermacetogenum, and Hypoxylon were enriched in soils with rapeseed residues, and Halanaerobiales, Rubrobacter, and Volutella were only present in soils with wheat residues.  The findings of this study suggest that soil C and N dynamics in the presence of the crop residues were driven by the selection of specific bacterial and fungal decomposers linked to the biochemical qualities of the crop residues.  If crop residue decomposition processes showed specific bacterial and fungal operational taxonomic unit (OTU) signatures, this study also suggests a strong functional redundancy that exists among soil microbial communities.

Key words: crop residue , C and N mineralization ,  enzyme activities ,  bacterial and fungal diversity