Trivedi Pankaj, Delgado-Baquerizo Manuel, Jeffries Thomas C, Trivedi Chanda, Anderson Ian C, Lai Kaitao, McNee Matthew, Flower Kenneth, Pal Singh Bhupinder, Minkey David, Singh Brajesh K
Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith South, NSW, 2751, Australia.
Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, 80523, USA.
Environ Microbiol. 2017 Aug;19(8):3070-3086. doi: 10.1111/1462-2920.13779. Epub 2017 Jun 22.
Soil carbon (C) stabilisation is known to depend in part on its distribution in structural aggregates, and upon soil microbial activity within the aggregates. However, the mechanisms and relative contributions of different microbial groups to C turnover in different aggregates under various management practices remain unclear. The aim of this study was to determine the role of soil aggregation and their associated microbial communities in driving the responses of soil organic matter (SOM) to multiple management practices. Our results demonstrate that higher amounts of C inputs coupled with greater soil aggregation in residue retention management practices has positive effects on soil C content. Our results provide evidence that different aggregate size classes support distinct microbial habitats which supports the colonisation of different microbial communities. Most importantly our results indicate that the effects of management practices on soil C is modulated by soil aggregate sizes and their associated microbial community and are more pronounced in macro-aggregate compared with micro-aggregate sizes. Based on our findings we recommend that differential response of management practices and microbial control on the C turnover in macro-aggregates and micro-aggregate should be explicitly considered when accounting for management impacts on soil C turnover.
土壤碳（C）的稳定化部分取决于其在结构团聚体中的分布以及团聚体内的土壤微生物活性。然而，在各种管理措施下，不同微生物群体对不同团聚体中碳周转的机制和相对贡献仍不清楚。本研究的目的是确定土壤团聚体及其相关微生物群落对土壤有机质（SOM）对多种管理措施响应的驱动作用。我们的结果表明，在留茬管理措施中，较高的碳输入量加上更大的土壤团聚度对土壤碳含量有积极影响。我们的结果证明，不同的团聚体大小类别支持不同的微生物栖息地，这有利于不同微生物群落的定殖。最重要的是，我们的结果表明，管理措施对土壤碳的影响受土壤团聚体大小及其相关微生物群落的调节，与微团聚体相比，在大团聚体中更为明显。基于我们的研究结果，我们建议在考虑管理措施对土壤碳周转的影响时，应明确考虑管理措施和微生物控制对大团聚体和微团聚体中碳周转的不同响应。
