農業管理慣行下における土壌微生物炭素経済戦略のトレードオフ：全球メタ分析

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:土壌微生物炭素経済戦略の全球的応答パターンと手法間（化学量論モデル・18O・13C）の差異を定量化した基盤的知見を提供する。

🏢実務担当者:有機施肥・保全耕起・輪作・間作が炭素放出を増やさず微生物炭素保持を高める点は、農業サプライチェーンの脱炭素・土壌炭素クレジット設計に活用できる。

🏛政策担当者:農地炭素貯留を促す政策・クレジット制度設計において、放出増を伴わない管理慣行を優先する根拠となり得る。

ABSTRACT Agricultural management profoundly influences soil carbon (C) dynamics by regulating microbial processes that drive C cycling. However, a comprehensive and globally integrated understanding of these mechanisms remains limited. In this study, we defined soil microbial carbon economic strategies (MCES) as four linked processes, including acquisition (β glucosidase and cellobiohydrolase activities), conversion (microbial biomass carbon), allocation (microbial carbon use efficiency), and release (soil CO 2 emissions). Based on 1957 observations from 140 field experiments, this study evaluated the responses of MCES to agricultural management and identified their underlying drivers at the global scale. Results showed that straw return significantly increased microbial C acquisition, conversion, and release by 27.0%, 55.1%, and 94.4%, respectively. Inorganic fertilization significantly increased microbial C allocation and release by 24.1% and 23.2%, respectively. By contrast, conservation tillage and organic fertilization significantly enhanced microbial C acquisition and conversion by 267.7% and 44.8%, respectively, without significantly increasing microbial C release. Crop diversification (rotation and intercropping) and vegetation restoration mainly increased microbial C allocation, as reflected by microbial carbon use efficiency, by 42.5% and 28.6%, respectively, indicating a shift toward more efficient microbial use of assimilated C rather than a broad stimulation of C acquisition, conversion, or release. Management effects on MCES were strongest in topsoil and neutral soils, crop type and climate further modulated these responses, with C 4 crops favoring microbial C conversion and allocation, and arid regions showing stronger increases in microbial C allocation and release. Significant increases in microbial C allocation were mainly detected using stoichiometric modeling and 18 O methods rather than 13 C methods. Globally, predicted microbial C acquisition increased with latitude, whereas microbial C allocation and release showed localized hotspots. These findings reveal contrasting responses among MCES and highlight organic fertilization, reduced soil disturbance, and diversified cropping systems as promising practices for enhancing microbial C retention while limiting potential C losses in agricultural soils.

• openalex https://doi.org/10.6084/m9.figshare.32449146.v1first seen 2026-09-22 04:36:53