What term describes the downward movement of a substance, such as a pesticide, through soil in solution?

What term describes the downward movement of a substance, such as a pesticide, through soil in solution?

• A. Leaching
• B. Phloem
• C. Phytotoxicity
• D. Nematicide

Answer: (A)

Leaching is the downward movement of a pesticide dissolved in water through soil. When you apply a chemical and rainfall or irrigation moves water through the soil, soluble portions of the pesticide can be carried down with that percolating water. The rate of leaching depends on soil texture and organic matter: sandy soils with little organic matter drain quickly and allow more rapid leaching, while soils rich in organic matter or clay tend to bind chemicals and slow their downward movement. This process can push active ingredients below the root zone and potentially into groundwater or non-target areas, so managing leaching involves timing applications to avoid heavy rainfall, choosing formulations with lower solubility or leaching potential, and using appropriate placement or incorporation practices. Phloem relates to the plant’s internal transport system, not movement through soil. Phytotoxicity is about a chemical causing injury to plants. A nematicide is a pesticide aimed at nematodes.

Leaching is the downward movement of a pesticide dissolved in water through soil. When you apply a chemical and rainfall or irrigation moves water through the soil, soluble portions of the pesticide can be carried down with that percolating water. The rate of leaching depends on soil texture and organic matter: sandy soils with little organic matter drain quickly and allow more rapid leaching, while soils rich in organic matter or clay tend to bind chemicals and slow their downward movement. This process can push active ingredients below the root zone and potentially into groundwater or non-target areas, so managing leaching involves timing applications to avoid heavy rainfall, choosing formulations with lower solubility or leaching potential, and using appropriate placement or incorporation practices.

Phloem relates to the plant’s internal transport system, not movement through soil. Phytotoxicity is about a chemical causing injury to plants. A nematicide is a pesticide aimed at nematodes.