過剰耕起が土壌を弱化させるメカニズムを解明(Earthquake scientists reveal how overplowing weakens soil)

2026-03-19 ワシントン大学(UW)

ワシントン大学の研究チームは、過剰な耕起(過耕作)が土壌構造を弱体化させる仕組みを実験農場で解明した。長期的な耕起により土壌粒子の結合が壊れ、密度や強度が低下し、地震時の揺れに対する脆弱性が増すことが示された。特に土壌の空隙構造の変化が力学特性に影響し、地盤の安定性を損なう要因となる。これにより農地管理が地震リスクにも関係することが明らかとなり、持続可能な農業や防災対策の観点から重要な知見を提供する研究である。

過剰耕起が土壌を弱化させるメカニズムを解明(Earthquake scientists reveal how overplowing weakens soil)
A plot of experimental land at Joe Collins’ Field near Harper Adams University, where University of Washington researchers travelled to collaborate on an agroseismology experiment examining the impact of tilling on soil moisture. Photo: Marine Denolle/University of Washington

<関連情報>

農業水理学と農業慣行が土壌水力学に及ぼす影響 Agroseismology and the impact of farming practices on soil hydrodynamics

Qibin Shi, David R. Montgomery, Abigail L.S. Swann, Nicoleta C. Cristea, […] , and Marine A. Denolle
Science  Published:19 Mar 2026
DOI:https://doi.org/10.1126/science.aec0970

Abstract

Impacts of farming practices on soil hydrodynamics are central to understanding agricultural landscapes covering almost half of the world’s habitable land. Combining observations from distributed acoustic sensing with physics-based hydromechanical modeling, we tracked minute-resolution, meter-scale seismic and hydrological changes across agricultural fields with controlled histories of tillage and compaction. We show that dynamic capillary effects in soil govern transient stiffness and moisture redistribution in disturbed soils, producing sharp post-rain velocity drops from near-surface saturation and large hysteretic velocity rebounds driven by evapotranspiration. Our seismically inverted estimates of saturation reveal how disturbance alters flux partitioning and storage, establishing agroseismology and distributed acoustic sensing as scalable, noninvasive probes of soil hydromechanics with the potential to improve Earth system models, land management, and hazard resilience.

1203農業土木
ad
ad
Follow
ad
タイトルとURLをコピーしました