土壌食物網が農地における炭素保持を促進(Soil Food Webs Boost Carbon Retention in Farmlands)

2025-11-19 中国科学院(CAS)

中国科学院応用生態研究所の研究チームは、土壌フードウェブが農地における光合成由来炭素の変換と貯留をどのように促進するかを明らかにした。野外試験と¹³C標識実験により、作物が固定した炭素が作物体から土壌、さらに微生物・微小動物・大型土壌動物へ移動する経路を追跡した。その結果、作物残渣(ストーバー)を圃場に還元することで、粒状有機炭素(POC)が約30.96%、鉱物結合有機炭素(MAOC)が約11.39%増加。土壌生物群集の構造が再編され、食物網のつながりが強化された。特に線虫を中心とする微小動物は炭素更新の約60.52%に寄与し、POCからMAOCへの移行を助ける重要な役割を果たした。細菌分解はPOC更新を、真菌分解はMAOC蓄積を支え、作物・土壌微生物・土壌動物の相乗作用により炭素貯留が強化されることが示された。

土壌食物網が農地における炭素保持を促進(Soil Food Webs Boost Carbon Retention in Farmlands)
Conceptual diagram illustrating the flow, transformation, and retention of 13C-labeled carbon through the crop, soil, and soil food web system. (Image by ZHANG Xiaoke)

<関連情報>

茎葉の回復は土壌食物網の調節を通じて光合成炭素の変換と隔離を促進する Stover return enhances the transformation and sequestration of photosynthetic carbon through regulating soil food web

Yijia Tian, Xinchang Kou, Tingting An, Liangjie Sun, Qi Li, Wenju Liang, Xiaoke Zhang
Journal of Cleaner Production  Available online: 23 October 2025
DOI:https://doi.org/10.1016/j.jclepro.2025.146910

Highlights

  • Stover return triggered photosynthetic carbon turnover into soil and soil food web.
  • Microfauna controlled the trade-off between soil active and stable carbon.
  • Crop, soil, and soil food web synergistically promoted the carbon transformation.

Abstract

In agroecosystems, the biological fixation of atmospheric carbon by crops through photosynthesis is one of the most important precursors of soil carbon sequestration. Residue return as a conservational agricultural management practice replenishes soil carbon substrates and triggers soil food web. However, there is still a lack of studies on the priming effect of residue return on photosynthetic carbon transformation and turnover, and then soil carbon sequestration through regulating soil food web, which hinders us from evaluating the efficiency and sustainability of resource utilization. To analyze the priming effect of residue return, stover return (SR) and stover removal (CK) were conducted in the maize field experiment. Then the situ 13C labeling microplot experiment was further carried out to trace crop photosynthetic carbon turnover pathway into soil on the basis of the field experiment. We found the contents of both particulate organic carbon and mineral-associated organic carbon were 30.96 % and 11.39 % higher in SR than in CK respectively, and the significant differences in the soil biota community composition was found between the both treatments in the field. The 13C labeling experiment showed the greater values of 13C from crop, soil (particulate and mineral-associated organic carbon), soil microbes and microfauna in SR than in CK on the 10th labeling day, which indicated photosynthetic carbon turnover into soil and soil food web was enhanced with increasing days. Compared to soil microbes and mesofauna, soil microfauna explained the 60.5 % of soil carbon renewal. Microfauna as an intermediary promoted crop photosynthetic carbon accumulation into the soil. Positive relationships among different soil biotic groups indicated that stover return strengthened the synergistic effects within the soil food web, thereby influencing the trade-off between soil active carbon and stable carbon. In conclusion, the stover return enhanced the incorporation of photosynthetic carbon into soil and the soil carbon sequestration through the synergistic effect of crop-soil-soil food web.

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