Herbicide Use in “Regenerative” No-Till Contaminates Waterbodies

February 19, 2021 | Vermont Public Radio (VPR) reports on revelations from a retired state scientist, Nat Shambaugh, who finds that farmers’ efforts to reduce agricultural runoff from fields into water bodies, by planting cover crops, has resulted in significant increases in the use of herbicides to kill off those crops. So as one kind of pollution is reduced, another has become intensified. In Vermont and elsewhere, there has been much attention paid to nutrient pollution of waterbodies and waterways from agricultural runoff, largely because phosphorous and nitrates from fertilizers lead to contaminated drinking water, as well as to blooms of algae (some of which have their own toxic byproducts) and hypoxic dead zones in water bodies. The most notorious of these dead zones in North America are at the mouth of the Mississippi River, as it empties into the Gulf of Mexico, and in Lake Okeechobee in Florida. Less attention has been given generally to the problem of pesticide residues and metabolites in agricultural runoff, which also threaten drinking water sources, ecosystem health, and biodiversity. The report from VPR indicates that the increases in herbicide use may well be contaminating the state’s watery gem, Lake Champlain, and questions whether the state’s Agency of Agriculture is acting sufficiently on its policy to reduce pesticide use. The Vermont official in charge of pesticide regulation has explained the idea behind this shift to chemical “no-till” (cover cropping plus herbicide kill-off of that crop). As dairy farmers instituted cover cropping to reduce nutrient runoff from their silage corn fields, they would adopt genetically engineered (GE) corn seed plus the herbicide Roundup, with which the GE seed must be paired, as a “trade” of one toxic chemical (atrazine) for another (glyphosate/Roundup). [Vermont Public Radio, As Farmers Plant cover Crops to Reduce Runoff, Report Says They Also Use More Herbicides, 2021.]