Fertilizers are lost from the soil through leaching, underground seepages, and run-off. Leaching occurs when excess water passes through the soil and carries soluble nutrients like nitrogen and potassium with it, thus removing them from the root zone. Underground seepages happen when water-soluble nutrients dissolve in water and are transported with it to groundwater reservoirs. Run-off occurs when water moves over the surface of the soil, carrying away the fertilizers. This can occur during heavy rainfall or irrigation. Sheet, gully, and wind erosion can also cause soil degradation, leading to the loss of nutrients, but they are not the main mechanisms of fertilizer loss from the soil. Therefore, fertilizers are lost from the soil mainly through leaching, underground seepages, and run-off.