Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

Abstract

Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

Assessment of Soil Suitability for Improvement of Soil Factors and Agricultural Management

“…The increased sodium saturation and salinization in arid and semiarid regions negatively affect soils' physical properties such as soil structure and hydraulic conductivity, and consequently adversely impact crop yield, and if the exchangeable sodium percentage passes 15, these soils are classified as sodic soils [64,65]. On the other hand, high-sodium saturation could be improved by the addition of gypsum [16,17,66].…”

Future of Sustainable Agriculture in Saline Environments

“…Sodium ions (Na + ) bind to the exchange sites on clay particles, increasing the chance of clay dispersal (Abrol et al 1988). Once dispersed, soils are susceptible to structural degradation, resulting in surface slaking and reduced infiltration rates (Paes et al 2014). Soil dispersal can also expose previously-occluded soil organic matter to decomposition, altering the microbial structure and carbon cycling of a soil (Rath and Rousk 2015).…”

Teores de metais pesados e sódio no solo e em cultivo de girassol adubado com lodo de esgoto

“…A aplicação do lodo de esgoto em solos agrícolas pode aumentar o teor de sódio do solo, podendo afetar a absorção de água e de nutrientes pelas plantas, em razão do aumento da pressão osmótica da solução do solo, ou indiretamente, pelo seu efeito dispersante sobre as argilas, causando desestruturação do solo e prejudicando a infiltração de água, aeração e crescimento das raízes (Garcia et al, 2009;Paes et al, 2013;Paes et al, 2014).…”