Article ID Journal Published Year Pages File Type
4573961 Geoderma 2012 8 Pages PDF
Abstract

The relative effects of Na+ and K+ on soil structural stability are not clearly defined by the existing literature. This is an important issue for the application of winery wastewater on soils as it contains high levels of K+ and varying levels of Na+. To evaluate the relative effects of Na+ and K+ on soil structural stability both surface and subsoil from a land application site for winery wastewater were used to assess changes in soil hydraulic conductivity in repacked soil columns. The soil was rich of smectite, 51–56%, with minor presence of illite, 5–8%, and kaolinite 10% clays. Solutions with sodium adsorption ratio (SAR) and potassium adsorption ratio (PAR) of 5–40, where the monovalent cation was Na+ or K+ and the divalent cation was Ca2 + or Mg2 + were used to leach the soil columns, at electrolyte concentrations ranging from 2.5 to 640 meq L− 1. In both surface and subsoil, percolating solutions with PAR or SAR, comprising all cation combinations, of 20 and 40 caused a decrease in hydraulic conductivity as electrolyte concentrations reduced. However, in PAR solutions the decreases in hydraulic conductivity were significantly smaller than the corresponding SAR solutions. These results indicated greater soil stability in the presence of K+ relative to Na+.

► Sodium cation solutions simulating winery wastewater cause reduction of HC. ► Greater soil stability in the presence of potassium. ► At SAR and PAR values of 5, there is little effects of Na+ or K+ on HC.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Earth-Surface Processes
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