Resumen

MARTINEZ-RODRIGUEZ, Oscar Germán et al. Water quality for agricultural use of the San Pedro River, Nayarit. Rev. Mex. Cienc. Agríc [online]. 2020, vol.11, n.3, pp.619-633.  Epub 30-Ago-2021. ISSN 2007-0934.  https://doi.org/10.29312/remexca.v11i3.2083.

The study area is of fluvian delta formation, with a predominance of cambisol and fluvisole soils. The main crops in the area are beans, corn, sorghum, tobacco and tomatillo. These are watered with water from the San Pedro River. Surface water, when it contains high concentrations of sodium or bicarbonate, can cause adverse effects in agriculture. With the objective of evaluating these effects, nine sampling sites were established in the riverbed and four samplings were carried out over a period of two years, in a rainy and dry season each year. The pH, EC, anions and major cations were determined, the hydrogeochemical type was established and the RAS, RASº, RASaj, PSI, CSR and the saturation index were calculated. In the section of the river from El Rosarito to El Mezcal, the water is bicarbonated sodium-calcium-magnesium and from Mexcaltitan to Boca de Camichin, it was chlorinated-sodium. The RAS in its different conceptualizations for the first section were from 0.38 to 1.58, the EC ranged between 131-367 µS cm-1 and the PSI<3%; while, for the last section, the RAS varied between 9.06-161.16, the EC between 2 350-4 3130 µS cm-1 and the PSI between 6.16-73.14%. The waters from the San Pedro de El Rosario to El Mezcal river turned out to be excellent to good quality. Chlorinated-sodium waters are not suitable for agricultural use.

Palabras llave : adjusted RAS; hydrogeochemistry; saturation index.