Rapid Decomposition of Brittle Rice Straw Reduces Greenhouse Gas Emissions and Shifts Carbon Allocation in Paddy Soils

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

🔬研究者:Provides experimental data on the interaction of straw type and water management, useful for modeling GHG emissions and carbon dynamics in paddy soils.

🏢実務担当者:Offers a practical residue management strategy (brittle straw + AWD) that can reduce emissions and maintain soil health, applicable to rice farming operations.

🏛政策担当者:Supports policies promoting alternate wetting and drying and improved straw varieties to mitigate agricultural GHG emissions, relevant to national climate targets.

イネ（Oryza sativa L.）わらの還元は土壌炭素（C）隔離を改善できるが、集約的なイネ栽培体系におけるその採用は、短い休閑期間（30日未満）によって制限されており、これは不完全なわらの分解を引き起こし、連続湛水（CF）下でのメタン排出を増加させる可能性が高い。難分解性繊維含有量が低く分解が速いことを特徴とする脆弱性イネわらは、この制約を克服できる可能性がある。しかし、間断灌漑（AWD）下でのその環境性能、例えばより広範な炭素配分については依然として不明である。この150日間のマイクロコズム試験では、わらの種類（脆弱性 vs. 非脆弱性）と水管理（CF vs. AWD）の相互作用が、対照的な2種類の水田土壌（砂壌土 vs. シルト質壌土）における温室効果ガス（GHG）排出、溶存炭素生成、土壌炭素貯留、および団粒形成に及ぼす影響を評価した。非脆弱性わらと比較して、脆弱性わらの還元は、CF下で正味GHG排出を約28.4%、AWD下で約39.6%削減した。脆弱性わらとAWDの組み合わせは、最も低い正味GHG排出（0.61 kg CO2-eq m−2）を生み出し、断続的な酸素供給が初期の分解関連排出リスクを効果的に緩和したことを示した。脆弱性わらはまた、AWD下で溶存無機炭素濃度を14.2%、硝酸態窒素濃度を64.3%増加させ、無機化の促進と潜在的な無機炭素の安定化を示唆した。わらの種類に関係なく、わらの還元は砂壌土で土壌炭素ストックを27.3%、シルト質壌土で29.6%改善し、同時にマクロ団粒の形成を促進した。全体として、本研究は、脆弱性イネわらとAWDを組み合わせることで、土壌炭素の利点を維持しながらGHG排出を削減できることを実証し、集約的なイネ栽培における有望な残渣管理戦略を提供するものである。

AI 翻訳（deepseek-v4-flash）。 正確を期す場合は下の原文を参照してください。

Rice (Oryza sativa L.) straw-return can improve soil carbon (C) sequestration, but its adoption in intensive rice systems is limited by short fallow periods (< 30 days), which likely lead to incomplete straw decomposition and increase methane emissions under continuous flooding (CF). Brittle rice straw, characterized by lower recalcitrant fiber content and rapid decomposition, may overcome this constraint; however, its environmental performance under alternate wetting and drying (AWD) remains unclear, such as broader C allocation. This 150-day microcosm study evaluated the interaction of straw type (brittle vs. non-brittle) and water management (CF vs. AWD) on greenhouse gas (GHG) emissions, dissolved C production, soil C storage, and aggregate formation in two contrasting paddy soils (sandy loam vs. silty clay loam). Compared with non-brittle straw, brittle straw returns reduced net GHG emissions by approximately 28.4% under CF and 39.6% under AWD. The combination of brittle straw with AWD produced the lowest net GHG emissions (0.61 kg CO2-eq m−2), indicating that intermittent oxygen input effectively mitigated the early decomposition-related emission risk. Brittle straw also increased the concentrations of dissolved inorganic C by 14.2% and nitrate by 64.3% under AWD, suggesting enhanced mineralization and potential inorganic C stabilization. Regardless of straw type, straw return improved soil C stocks by 27.3% in sandy loam and 29.6% in silty clay loam, while also promoting macroaggregate formation. Overall, this study demonstrated that coupling brittle rice straw with AWD can reduce GHG emissions while maintaining soil C benefits, offering a promising residue management strategy for intensive rice cultivation.

• crossref https://doi.org/10.3390/agronomy16111035first seen 2026-05-25 05:33:28 · last seen 2026-06-06 05:34:42