The scientists used a combination of geophysical methods to study how water moves through soil. By conducting lab experiments and using electrical resistivity and ground penetrating radar, they tracked changes in soil moisture over time. They found that as soil moisture increased, electrical resistivity decreased and dielectric constant increased. By analyzing these changes, they were able to estimate how water infiltrates the soil and determine important soil properties like infiltration rate and hydraulic conductivity. The study suggests that their model can accurately predict average changes in water infiltration, but more research is needed to understand how these properties vary across different areas of soil.