Which nutrient movement process depends on water flow?

• A. Diffusion
• B. Adsorption
• C. Mass flow
• D. Capillary rise

Answer: (C)

Mass flow describes the transport of nutrients with the bulk movement of water through soil. When water moves—due to rainfall, irrigation, or plant water uptake creating flow in the soil solution—dissolved nutrients are carried along with it. This makes nutrient transfer highly dependent on how much and how fast water is moving through the root zone.

Diffusion, by contrast, happens due to concentration differences and can occur even with little or no overall water movement. Adsorption is not a transport mechanism; it’s the binding of nutrients to soil particles, which can limit or slow movement rather than drive it. Capillary rise is a way water itself can move in soil, but the specific process that moves nutrients with that water flow is mass flow.