Evaluation of osmotic potentials in soils and coastal waters of Oaxaca, México, using prediction equations

Abstract

The objective of this study was to evaluate the osmotic coefficients of fifteen samples of soils and fifteen irrigation waters of the coast of Oaxaca, in which the parameters electrical conductivity (EC), total dissolved solids (STD) and osmotic potential (ψπ) interact with the model Ψπ = K₃ x TDS, obtained from the literature and required to simulate osmotic or toxic salt trends in the water-soil-plant relationship. Its application can aid in the prevention of damage of crops by salinity. In laboratory, physicalchemical analysis of soils and waters were performed; in cabinet, predictive equations were done. The Ψπ obtained are close to those of the theoretical coefficient -0.036 x CE (dS m^-1) of the Salinity Laboratory of the United States of America. Both methods present a high correlation (r = 0.99). The Ѱπ evaluated are produced by a hydrochloric salinity with an intense osmotic effect. The equations of the proposed model predict well the saline osmotic phenomenon.