Groundwater quality for agricultural use in Zacoalco de Torres and Autlan de Navarro, Mexico

In Mexico, one of the main sources for agricultural irrigation is groundwater, which irrigates approximately 2 million hectares, accounting for 75% of the country's rural and urban water volume. These water resources are affected by industrial waste and residual pollutants, as well as the leaching of chemical substances from agricultural soils. In order to evaluate the physical and chemical characteristics of groundwater, this study was conducted in Zacoalco de Torres and Autl á n de Navarro. Sampling was conducted during the dry and rainy seasons in 2017. The sampling locations were deep wells and water wheels. A total of 48 samples were obtained from two sites. In each sample, pH value, anion and cation, electrical conductivity (EC), residual sodium carbonate (CSR), sodium adsorption ratio (SAR) and hydrogeochemical classification were analyzed. The underground water of Zacoalco is mostly chlorinated-magnesic and in Autlán it is bicarbonate-magnesic with medium and low concentrations, so it is recommended for irrigation. With respect to salinity, Zacoalco has 40% high salinity water in dry conditions and 66% medium salinity water in rains; Autlan has 75% high salinity water in dry and 75% medium salinity water in rainfall, so its use shows moderate restrictions.