Saturação do complexo de troca de solos oxídicos com sódio

Abstract

This study investigated the influence of physical, chemical and mineralogical properties of three oxidic soils in their potential sodification. In this evaluation, samples collected in the B horizon of two Oxisol and a Ultisol were used, which presented, respectively, high presence of the mineral kaolinite, hematite and gibbsite. Samples were subjected to physical, chemical and mineralogical analysis and filled soil columns were submitted to leaching with solutions of electrical conductivity (CE) of 8.0 dS m-1 and sodium adsorption ratio (SAR) 0, 10, 20, 30, 40 and 50 (mmol L-1)0.5, in three replications. The exchangeable sodium percentage (ESP) and exchangeable sodium adsorption ratio (ESR) were obtained by calculation from the values of exchangeable sodium in the soil. The increase in the SAR of percolation solution provided an increase in the ESR and ESP of all soils and was influenced by the mineralogy, weathering degree and clay content of soil. The analysed soils can receive waters with high SAR and EC without suffering significant sodification.