Evaluation of nitrogen and total phosphorus in agricultural runoff in the lower basin of the Usumacinta River (Tabasco, México)

Abstract

Ferat, M.A., Galaviz-Villa, I., Partida-Sedas, S. 2020. Evaluation of nitrogen and total phosphorus in agricultural runoff in the lower basin of the Usumacinta River (Tabasco, México). Ecosistemas 29(1):1879. https://doi.org/10.7818/ECOS.1879 The Usumacinta river basin has the greatest extension and hydrological development in Mesoamerica. This basin covers a total area of more than seven million hectares, being the lower basin exclusively within Mexico territory. The objective of the present work was to evaluate the presence of total phosphorus, total nitrogen and ammoniacal nitrogen in agricultural runoffs, and its effect on the surface water quality of the Usumacinta River, Tabasco. Seventeen runoff water samples were taken in the municipalities of Tenosique and Balancán, Tabasco and the concentration of total phosphorus (365.1-1993), total nitrogen (351.2-1993) and ammoniacal nitrogen (EPA 350.1-1993) was determined. The results obtained indicate that the concentrations of ammoniacal nitrogen and total phosphorus exceed the ecological criteria of water quality CE-CCA-001/89 for the protection of aquatic life (N-NH3 0.06 mg L-1, Pt 0.1 mg L-1) and total nitrogen concentrations exceed the maximum permissible limits set by the United States Environmental Protection Agency 2002, 2006.