Development of integrated soil management technology towards rehabilitation of degraded soils in the Tropics

2022 Fiscal Year Final Research Report

• Project/Area Number: 18H02315
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 41050:Environmental agriculture-related
• Research Institution: Aichi University
• Principal Investigator: Kosaki Takashi 愛知大学, 国際コミュニケーション学部, 教授 (00144345)
• Co-Investigator(Kenkyū-buntansha): 村瀬 潤 名古屋大学, 生命農学研究科, 教授 (30285241) ; 杉原 創 東京農工大学, (連合)農学研究科(研究院), 准教授 (30594238) ; 沢田 こずえ 京都大学, 地球環境学堂, 研究員 (60795285)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 劣化土壌の修復 / サブサハラ・アフリカ / 生態系の持続的管理 / 土壌微生物の群集・機能 / 炭素利用効率

Outline of Final Research Achievements

The negative spiral of poverty and hunger caused by soil degradation is becoming more severe especially in tropical regions. In this research, in addition to the conventional quantitative management of organic matter, we hypothesized that the management of soil microbial functions, such as mineralization/immobilization of organic matter, should be possible to effectively rehabilitate and conserve degraded soil. We conducted the field experiments in Tanzania and India, to reveal the relationship between the soil microbial community and its function under different land managements.
The results showed that 1) the difference in the microbial carbon use efficiency caused by land use (forest and cropland) was mainly due to the difference in the fungal community, 2) In a large amount of farm yard manure application plot, soil microbial function, such as carbon mineralization, was improved, resulting in the efficient accumulation of organic matter in the soil.

Free Research Field

土壌学

Academic Significance and Societal Importance of the Research Achievements

『持続可能な開発目標(SDGs)』の最優先課題「貧困と飢餓の撲滅」は農学が解決すべき究極の目標であり、劣化土壌の修復は喫緊の課題である。本研究では、熱帯畑作地における土地利用が土壌微生物群集やその機能に与える影響について、SIP法などの先端技術を駆使することで解明した結果、従来想定されていた細菌群集に加えて、畑地の炭素循環への貢献度が不明瞭であった糸状菌群集の果たす役割が大きいことを明らかにした。また熱帯畑作地における土壌壌微生物の機能改善に必要な堆肥施用技術に関する新規知見も得られた。今後これらの知見を融合・発展することで、熱帯地域における劣化土壌修復技術の社会実装が可能になる。