Agroseismology and the impact of farming practices on soil hydrodynamics.

The 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 and 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. Editor's summary: The effects of farming practices on soil health are typically measured by direct sampling or satellite and airborne sensing, with neither translating well to field scale. Shi et al. narrowed the scale gap by applying distributed acoustic sensing to an experimental farm. Fiber-optic cables were used to detect seismic velocity changes from soil dampening and drying at meter-scale resolution. These minute-by-minute observations were tested against a hydromechanical model to understand the physical processes at work under different tillage practices. Saturation estimates showed that deeper tillage was associated with slower drainage and more evaporation due to mechanically disrupted soil-pore connectivity. —Angela Hessler [ABSTRACT FROM AUTHOR]