Pedosphere 36(3): 722--737, 2026
ISSN 1002-0160/CN 32-1315/P
©2026 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Straw return strengthens straw C-assimilating bacterial diversity and interactions especially in soil small macroaggregates and microaggregates |
Qian ZHANG1, Yaxian WANG1, Chao AI2, Tengfei GUO3, Shuyan FAN1, Kai SHENG1, Yilun WANG1 , Hui LI1 |
1State Key Laboratory of High-Efficiency Production of Wheat-Maize Double Cropping, Resources and Environment College, Henan Agricultural University, Zhengzhou 450046 (China);
2 Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China);
3 Institution of Plant Nutrition and Environmental Resources, Henan Academy of Agricultural Sciences, Zhengzhou 450002 (China) |
| ABSTRACT |
| Soil aggregates, which provide heterogeneous habitats for microbiomes regulating the organic matter decomposition process, are highly sensitive to fertilization regimes. Exploration of straw C-assimilating microbial community diversity in soil aggregates responding to inorganic/organic fertilization could largely contribute to understanding the straw nutrient transformation process in arable soil. In this study, the soils subjected to 8-year different fertilization regimes of no nitrogen (N) fertilization (control, CK), inorganic fertilization (NPK), and inorganic fertilization with straw return (NPKSw) were collected to establish soil microcosms with 13C/15N-labeled maize straw incorporation. The DNA-stable isotope probing approach was used to explore the bacterial community composition, structure, and co-occurrence network of the straw C assimilators in large macroaggregates (LMA, > 2 mm), small macroaggregates (SMA, 250-2 000 μm), microaggregates (MIA, 53-250 μm), and silt and clay class (SIC, < 53 μm) during a 1-year incubation. The results demonstrated that straw incorporation induced a strong priming effect and promoted soil macroaggregation in NPKSw soil. The straw C-assimilating bacterial community was preferentially influenced by fertilization regimes, with significantly lower α-diversity in NPK soil than in CK and NPKSw soils. Besides the dominance of Actinobacteriota and Proteobacteria in the 13C-labeled bacterial community, inorganic fertilization improved the relative abundance of Acidobacteriota, but reduced that of Chloroflexi. Moreover, the long-term inorganic fertilization accelerated the storage of C and N in smaller aggregates, thereby shaping a more loose and competitive straw C-assimilating bacterial community structure in MIA and SIC. Comparatively, continuous straw return benefited soil macroaggregate formation and the associated C and N storage under exogenous C input and strengthened the interactions of straw C assimilators, particularly in SMA and MIA. Key taxa Alsobacter metallidurans, Rhodanobacter, Nocardioides, Ramlibacter, Sphingomonas, Gaiellales, Gemmatimonadaceae, and Caulobacteraceae showed the most links with other species in SMA and MIA of NPKSw soil. These findings emphasized the vital function of straw return in soil biodiversity and sustainability under intensive farming and advanced the understanding of straw utilization by the key bacterial community at the aggregate level. |
| Key Words: 13C/15N-labeled maize straw|fertilization regimes|macroaggregation|microbial community|soil aggregates|stable isotope probing |
| Citation: Zhang Q, Wang Y X, Ai C, Guo T F, Fan S Y, Sheng K, Wang Y L, Li H. 2026. Straw return strengthens straw C-assimilating bacterial diversity and interactions especially in soil small macroaggregates and microaggregates. Pedosphere. 36(3): 722-737. |
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