Eluviation is the process by which soluble substances are removed from the upper layers of the soil. Essentially, it involves the movement of water through the soil, which carries dissolved materials with it as it percolates down through the layers of the soil. As the water moves through the soil, it tends to pick up and transport soluble substances such as minerals and organic compounds. These substances are then carried down through the soil layers and may eventually end up in lower layers or be carried away by groundwater. This process can have important effects on the chemical properties of the soil, as it can impact the availability of nutrients for plants and other organisms that depend on the soil ecosystem.