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

Abstract

Objective: Assess the risk of groundwater contamination due to the application of pesticides and the amount of nitrogen leached 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 at 30 groundwater sampling points was determined by using the Mexican regulation N0M-041-SSA1-1993 and the EPA 608 and EPA 608.1 methods 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 fractionated doses (2, 3 y 4). Results: Pesticides such as ?-hexachlorocyclohexane (?-HCH), heptachlor heptachloroepoxide, ?-endosulfan, ? endosulfan, sulfate-endosulfan, aldrin, dieldrin and dichlorodiphenyldichloroethylene (4.4’DDE) were found in groundwater of deep wells of agroecosystems with sugarcane. Application of low doses of N resulted in lower losses of N due to leaching. A dose of 150 kg ha-1 of N, applied in two, three, and four fractions, generated N losses between 15.40 to 18.18 kg ha-1, which means a loss of up to 12.1%. Conclusions: Groundwater contamination by agrochemicals, such as pesticides is indubitable; so, reducing such contamination should be a priority for crop growers involved. Also, nitrogen, soil and water management and conservation practices must be done. This will result in a less negative impact to the environment and public health. Water and nitrogen fertilizers management at plot level are to be improved in order to increase water irrigation and nitrogen efficiency in agricultural areas.