When water moves through soil pores carrying dissolved nutrients with it, this is best described as?

• A. Diffusion
• B. Osmosis
• C. Mass flow
• D. Capillary action

Answer: (C)

Mass flow is the bulk movement of water through soil pores, carrying dissolved nutrients with it as water moves under hydraulic pressure and gravity. This means nutrients dissolved in soil water travel together with the moving water, especially during infiltration, percolation, or root uptake events. Diffusion, by contrast, depends on concentration gradients and acts slowly, especially when water movement is limited. Osmosis involves water movement across membranes, not the general transport of nutrients through soil. Capillary action describes water rising or moving in narrow pores due to surface tension, not the concurrent transport of solutes with bulk water flow. So the scenario described best matches mass flow.