The study looked at how adding different amounts of biochar to sand and loam soils affects water flow and soil structure. They found that adding biochar decreased water infiltration in sand but increased it in loam. Biochar also increased the soil's ability to hold water in both types of soil. The impact of biochar on soil structure was more noticeable in sand than in loam. These results show that biochar can improve soil quality by changing how water moves through it.