Earthquake scientists reveal how overplowing weakens soil at experimental farm

Summary

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 Researchers (from left to right) Ethan Williams, Joe Collins, Simon Jeffrey lay the fiber optic cable just below the surface of a test near Harper Adams University. Photo: Marine Denolle/University of Washington Senior author Marine Denolle, a UW associate professor of Earth and space sciences, poses in front of the test field with her daughter, Catherine, on a rainy field day. Photo: Marine Denolle/University of Washington Ethan Williams, a former UW postdoctoral researcher in Earth and space sciences, now an assistant professor at UC Santa Cruz, uses the highly portable DAS data collection system at the experimental farm. Photo: Marine Denolle/University of Washington Previous imageNext image Plowing, or tilling, is an age-old agricultural practice that readies the soil for planting by turning over the top layer to expose fresh earth. The method — intended to improve water and nutrient circulation — remains popular today, but concerns about soil degradation have prompted some to return to regenerative methods that disturb the soil less. In a new study, a team led by University of Washington researchers examined the impact of tilling on soil moisture and water retention using methods originally designed for monitoring earthquakes. Researchers placed fiber optic cables alongside fields at an experimental farm in the United Kingdom and recorded ground motion from plots receiving different amounts of tillage and compaction from tractor tires pulling farm equipment. The study, published March 19 in Science, shows that tilling and compaction disrupt intricate capillary networks within the soil that give it a natural sponge-like quality. “This study offers a clear explanation for why the process of ...