Some herbicides leave a residue in the soil that can damage subsequent crops.
When treated with lime to raise the pH above 6.0, herbicide breakdown proceeds normally. Other Group 2 herbicides do not breakdown at high soil pH. Classic and Peak herbicides remain in the soil for long periods of time when the pH is above 7.5. Sulfur may be useful to lower the pH below 7.5 to allow the herbicide residues to breakdown. Experience has shown that sugar beets, tomatoes, potatoes, cole crops, grapes and strawberries are sensitive to Group 2 herbicide residues. Experience has also shown that until the pH is corrected, herbicide residues may remain in the soil for many years.