Which is a recommended best management practice for preventing contamination of surface and groundwater by pesticides?

Which is a recommended best management practice for preventing contamination of surface and groundwater by pesticides?

• A. Use terrace and conservation tillage practices
• B. Increase pesticide frequency
• C. Deep plowing only
• D. Use chemical fertilizers

Answer: (A)

Reducing runoff and soil erosion is the key idea. Pesticide movement into surface and groundwater mainly happens when rainwater or irrigation causes runoff carrying residues or sediment, or when water infiltrates and leaches chemicals through the root zone. Terracing breaks a slope into flatter sections, slowing water flow, increasing time for infiltration, and trapping sediment. That means less pesticide-laden sediment reaches streams and rivers. Conservation tillage keeps crop residue on the soil surface, protecting the soil from erosion and further promoting infiltration, which also reduces the amount of pesticide carried away with soil particles. Together, these practices cut both surface runoff and sediment transport, lowering the chance that pesticides contaminate water supplies. Choices that advocate more frequent pesticide applications don’t address transport pathways and can worsen contamination risk, while deep plowing alone doesn’t reliably reduce runoff or erosion and may disturb soil structure, potentially increasing movement of pesticides. Using chemical fertilizers doesn’t tackle pesticide transport at all.

Reducing runoff and soil erosion is the key idea. Pesticide movement into surface and groundwater mainly happens when rainwater or irrigation causes runoff carrying residues or sediment, or when water infiltrates and leaches chemicals through the root zone. Terracing breaks a slope into flatter sections, slowing water flow, increasing time for infiltration, and trapping sediment. That means less pesticide-laden sediment reaches streams and rivers. Conservation tillage keeps crop residue on the soil surface, protecting the soil from erosion and further promoting infiltration, which also reduces the amount of pesticide carried away with soil particles. Together, these practices cut both surface runoff and sediment transport, lowering the chance that pesticides contaminate water supplies.

Choices that advocate more frequent pesticide applications don’t address transport pathways and can worsen contamination risk, while deep plowing alone doesn’t reliably reduce runoff or erosion and may disturb soil structure, potentially increasing movement of pesticides. Using chemical fertilizers doesn’t tackle pesticide transport at all.