Environmentalists also complain that increased irrigation for crops has led to a depletion of ground water and an increase in the salinity of the soil. Many ground wells in the United States may be polluted, though usually from hazardous waste (such as dumped oil) rather than from fertilizers or pesticides. | Environmentalists also complain that increased irrigation for crops has led to a depletion of ground water and an increase in the salinity of the soil. Many ground wells in the United States may be polluted, though usually from hazardous waste (such as dumped oil) rather than from fertilizers or pesticides. |