農学的管理による農地土壌の炭素隔離：メカニズム、エビデンス、会計境界、研究優先課題

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

🔬研究者:土壌炭素の追加性・永続性・測定境界を扱う研究設計（全層・等価土壌質量・分画別評価）の指針として有用。

🏢実務担当者:農産物サプライチェーンの脱炭素・炭素クレジット調達を検討する企業は、不耕起や堆肥の主張を全体系GHGと土壌深度で検証すべきと理解できる。

🏛政策担当者:農地炭素クレジット制度や吸収量報告の算定ルール設計で、土壌質量基準・深度・非CO2ガスを含むMRV要件の必要性を示す。

Agricultural soils have lost substantial organic carbon through land conversion, intensive cultivation and insufficient organic inputs, creating a technically important but highly context-dependent opportunity for carbon restoration. This critical narrative review evaluates whether agronomic management can produce additional, measurable and sufficiently durable soil organic carbon (SOC) gains while maintaining agricultural production. Literature published from 1 January 1990 to 6 July 2026 was considered, with earlier or later-dated online records excluded from the evidentiary synthesis when outside this interval. The evidence indicates that SOC responses are governed principally by changes in plant-derived carbon inputs, microbial transformation, mineral association, aggregation, erosion and vertical redistribution rather than by any agronomic label alone. Cover crops, diversified rotations that increase biomass inputs, residue retention, perennial phases and agroforestry generally provide credible pathways for endogenous carbon accrual, although effect sizes vary with biomass production, soil mineralogy, climate, starting SOC and duration. Reduced and no-tillage frequently increase near-surface SOC but do not consistently increase whole-profile stocks when equivalent soil mass and deeper sampling are used, making tillage a particularly sensitive case for carbon accounting. Manure, compost and biochar can substantially increase measured soil carbon, but their climate value depends on carbon-source counterfactuals, processing emissions, displacement of organic resources and non-CO₂ greenhouse gases. Nutrient and water management can enhance SOC indirectly by increasing crop carbon inputs, yet gains must be evaluated against fertiliser-related nitrous oxide and energy emissions. Across practices, finite sink capacity, reversibility, spatial heterogeneity and measurement uncertainty constrain claims of permanent sequestration. The most defensible strategy is therefore not a universal practice hierarchy, but context-specific agronomic design that increases photosynthetic carbon inputs, protects soil from loss, verifies stock change across an appropriate soil mass and depth, and evaluates whole-system greenhouse-gas consequences. Future research should prioritise long-term, profile-scale, carbon-source-aware experiments and monitoring frameworks that connect total SOC change with particulate and mineral-associated fractions, crop performance, permanence and full greenhouse-gas accounting.

• openalex https://doi.org/10.9734/ijecc/2026/v16i105699first seen 2026-10-12 04:40:54