Which process describes the downward movement of soluble nutrients with percolating water?

• A. Leaching
• B. Adsorption
• C. Mineralization
• D. Immobilization

Answer: (A)

Leaching is the downward movement of soluble nutrients with percolating water through the soil profile. When rain or irrigation infiltrates, water carries dissolved nutrients down through the soil pores, which can deplete the upper soil layers and potentially reach groundwater. This differs from adsorption (ions sticking to soil particles), mineralization (organic matter breaking down to release inorganic nutrients), and immobilization (microbes taking up inorganic nutrients into biomass), which describe retention or transformation of nutrients rather than their downward transport with water.