A basic study on elucidation of crumb re-forming factors

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06144
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40010:Forest science-related
• Research Institution: Shinshu University
• Principal Investigator: Ono Hiroshi 信州大学, 学術研究院農学系, 助教 (00231241)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 団粒 / 森林土壌 / 団粒再形成

Outline of Final Research Achievements

In order to clarify the process of re-formation of soil aggregates in forest soils destroyed by soil disturbance, laboratory and field culture experiments were conducted using prepared soil aggregate samples.
In the indoor culture experiment, clusters were re-formed after 4 weeks of incubation, and the repetition of moderate drying and wetting was important for the re-formation of aggregates. In the field culture experiment, aggregates were re-formed after 3-4 weeks of incubation. The surface cover of the sample affected the improvement of soil physical properties associated with the re-formation of clusters, and the improvement of soil physical properties was inhibited under the no-cover condition.
These results indicate that the soil aggregates re-form in a relatively short time, that the moisture condition affects the re-formation process of soil aggregates, and that the protection by soil cover is important for the improvement of soil physical properties.

Free Research Field

治山（山地森林地帯における水土保全）

Academic Significance and Societal Importance of the Research Achievements

団粒が発達した森林土壌は浸透・透水性が高く，水土保全上重要な役割を担う。しかし近年，大型林業機械の導入が進み，土壌攪乱による団粒破壊に伴う森林土壌の水土保全機能の低下が危惧される。本研究では攪乱された土壌の再生を目標に，破壊された団粒の再生に関して，その可能性や，再生に関わる要因や必要な時間に関して検討した。その結果，野外条件下においても団粒が短期間で再生すること，団粒の再生には適度な乾燥と湿潤の繰り返しが重要であること，団粒再成に伴う土壌物理性の回復には土壌表面の被覆が重要な役割を果たすことなどが明らかになった。これらの知見は土壌再生に向けた今後の取り組みの大きな指針となるものである。