Groundwater Contamination due to the Use of Agrochemicals in Sugar Cane Agroecosystems

Objective: To assess the risk of groundwater contamination due to the application of pesticides and the amount of nitrogen lost by leaching, in agroecosystems with sugar cane, in the area of influence of sugar mills, La Gloria y El Modelo, Veracruz, Mexico. Methodology: The presence of pesticides in 30 groundwater sampling points was determined based on the NOM-041-SSA1-1993 standard and the methods of EPA 608 and EPA 608.1 described by the Environmental Protection Agency (EPA). Nitrogen (N) loss by leaching was assessed evaluating nine treatments by combining two factors: dose (250, 200 and 150 kg ha1 of N) and application of fractionated doses (2, 3 y 4).Results: Pesticides such as -HCH, heptachlor, heptachlor epoxide, -endosulphan,  endosulphan, endosulphan sulfate, aldrin, dieldrin and 4.4’DDE were found in deep-well water. Application of low doses of N resulted in lower losses of N due to leaching. A dose of 150 kg ha1 N, applied in two, three and four fractions, resulted in losses of N between 15.40 and 18.18 kg ha1. Conclusions: Groundwater contamination by pesticides is evident. Therefore, its reduction must be a priority for crop production, and soil and water conservation practices. This will result in a less negative impact to the environment and public health. Water and nitrogen fertilizers management, at plot level, must be improved, in order to increase water irrigation and nitrogen efficiency in agricultural areas.