What is the term for the downward movement of a substance with water through soil?

The term that refers to the downward movement of a substance with water through soil is known as leaching. This process occurs when rainwater or irrigation causes solutes, such as nutrients or contaminants, to be transported downward through the soil profile. As water moves, it carries away dissolved substances, which can negatively affect soil quality or contribute to groundwater contamination.

Leaching is particularly important in both agriculture and environmental science because it influences the availability of nutrients in the soil for plants as well as the potential for pollutants to reach water supplies. Understanding this process helps in managing soil health and water quality effectively.