Which term describes the downward movement of pesticide through soil with water movement?

Which term describes the downward movement of pesticide through soil with water movement?

• A. Leaching
• B. Runoff
• C. Vapor Drift
• D. Fog

Answer: (A)

Leaching is the downward movement of pesticide through soil as water moves through the soil profile. When rain or irrigation infiltrates the ground, soluble pesticides can dissolve in that water and be carried downward with it, potentially reaching deeper soil layers or groundwater. How much leaching occurs depends on the chemical’s water solubility and how strongly it adsorbs to soil particles—highly soluble, weakly adsorbed pesticides are more likely to move with percolating water, especially in sandy soils or after heavy rainfall. This is different from runoff, where water moves across the surface and can carry pesticides to surface water, and from vapor drift, which involves movement through the air as a vapor. Fog isn’t a standard mechanism for downward soil movement of pesticides.

Leaching is the downward movement of pesticide through soil as water moves through the soil profile. When rain or irrigation infiltrates the ground, soluble pesticides can dissolve in that water and be carried downward with it, potentially reaching deeper soil layers or groundwater. How much leaching occurs depends on the chemical’s water solubility and how strongly it adsorbs to soil particles—highly soluble, weakly adsorbed pesticides are more likely to move with percolating water, especially in sandy soils or after heavy rainfall. This is different from runoff, where water moves across the surface and can carry pesticides to surface water, and from vapor drift, which involves movement through the air as a vapor. Fog isn’t a standard mechanism for downward soil movement of pesticides.