Contamination by the Herbicide 2,4-D in the Agro-Industrial Karst of Yucatán, México

Agribusiness is the main economic activity in northeastern Yucatán, México. The production of forage grasses for livestock feed requires weed control, achieved through chemical methods, with the herbicide 2,4-D being the most widely used in the region. This research quantified the presence of 2,4-D in groundwater in Sucilá, Yucatán, during 2023. Twenty ranches with different stocking rates (organisms/hectare) were evaluated. Groundwater samples and soil cores were collected in two climatic seasons (dry and rainy) to relate soil properties and herbicide concentration to the weather. The results showed that the concentration of 2,4-D was higher during the rainy season (September 2023), with values between 1.6 and 3.6 mg 2,4-D/L, but no differences were observed among stocking rates. Soil organic matter was different between seasons, and cation exchange capacity changed among stocking rates. Continuous irrigation, coupled with the application of agrochemicals, is likely impairing the water quality of groundwater in this area of the Yucatan.