What is runoff?

• A. Water evaporating from leaves
• B. Soil compaction
• C. Pesticide concentrating in weeds
• D. Water carrying pesticide away

Answer: (D)

Runoff is the flow of water that moves across the soil surface after rain or irrigation, carrying substances along with it. The idea that water carrying pesticide away fits runoff perfectly, because it describes water that travels over the land and can pick up and transport pesticides out of the target area. Evaporation from leaves is a drying/transfer process away from the plant, not surface water movement. Soil compaction affects how well water infiltrates, but runoff itself is the surface flow, not the compaction. Pesticide concentrating in weeds describes where the chemical goes in plants, not how water physically moves across the landscape. Reducing runoff involves practices that improve infiltration and protect the soil surface, like proper irrigation and maintaining cover.