Which practice is recommended as a best management practice to prevent contamination of surface groundwater by pesticides?

• A. Use terraces and conservation tillage practices
• B. Bleach the field after spraying
• C. Add more water to dilute the pesticide
• D. Plant a cover crop only after harvest

Answer: (A)

Preventing pesticides from reaching surface water hinges on reducing runoff and erosion so fewer pesticides are carried off the field. Using terraces and conservation tillage is the best management practice because terraces slow and infiltrate water on sloped land, reducing runoff velocity and volume, while conservation tillage leaves crop residues on the surface to protect soil from erosion and to improve infiltration. This combination minimizes the transport pathways that move pesticides into surface waters. Other options don’t address these pathways: bleaching the field isn’t a valid or safe method to manage residues; diluting with more water can spread pesticides and increase total load; planting a cover crop after harvest misses the period when protection is most needed.