The effect of active base production by plants in rhizosphere soils on soil carbon sequestration

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K12299
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Rakuno Gakuen University
• Principal Investigator: Hobara Satoru 酪農学園大学, 農食環境学群, 教授 (70391159)
• Co-Investigator(Kenkyū-buntansha): 松本 真悟 島根大学, 学術研究院農生命科学系, 教授 (00346371) ; 森泉 美穂子 龍谷大学, 農学部, 教授 (10220039) ; 澤本 卓治 酪農学園大学, 農食環境学群, 教授 (60364246)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 土壌炭素 / 土壌有機物 / 根圏土壌 / ケイ酸吸収 / 炭素隔離

Outline of Final Research Achievements

The objective of this study was to elucidate the effect of reactive base production by plants in rhizosphere soils on soil carbon sequestration. First, we investigated the rhizosphere soils of rice and other plants through several cultivation experiments, and found that the rhizosphere of rice plants with high silica absorption capacity has high levels of aluminum, iron, and adsorbed dissolved organic carbon, suggesting that the bases in the rhizosphere soil are activated by plant absorption of silica, and are associated with organic matter, leading to carbon accumulation. Experiments on the decomposition of recalcitrant soil organic matter suggested that the addition of substances that promote the desorption of reactive base-organic matter associations may accelerate decomposition. Thus, the present study clarified the relationship between the reactivity of bases in the plant rhizosphere and soil carbon sequestration.

Free Research Field

環境科学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、植物が根圏土壌の塩基活性化や植物根が関係する新たなプロセスを通じて土壌の炭素蓄積隔離に影響するメカニズムを提示するとともに、そのプロセスによって蓄積する炭素が将来的に放出される過程でも同様の塩基と有機物の結びつきが深く関係していることを示唆している。これらの研究成果から、土壌中における活性塩基と有機物の関係は、植物を介して土壌への難分解性有機物および炭素の蓄積と放出の双方に関与すると考えられ、今後これが地球や地域の規模でどれほどの影響に及ぶかについてさらなる研究が必要と考えられた。