Movimentação de cátions no perfil de um Argissolo Amarelo sob condicionantes

Abstract

The present study aimed to evaluate the movement of cations (Ca, Mg, K and Na) in the profile of an Argissolo Amarelo after application by incorporating soil conditioners: dolomitic limestone, gypsum and hydrogel, individually or in combination, under irrigation with saline water. 80 cm soil columns were used, reconstructing the profile of an Argissolo Amarelo from the municipality of Palhano-CE. Limestone and gypsum were incorporated in the first 15 cm of the profile, applied in single doses to reach 100% of base saturation in the first 30 cm and two hydrogel doses (0 and 1g / kg of soil) incorporated in the first 5 cm from the profile. All columns received a layer of 630 mm of saline water (EC = 2.96 dS/m and RAS = 12), applied in 8 fractions of 78.75 mm per week, measuring the volume of percolated water and leached cations. After the columns were disassembled, the soil was separated into 5 cm layers, in the first 30 cm of the profile and 10 cm, in the 30 to 80 cm of the profile, the exchangeable cations were determined. Gypsum applied individually or combined with limestone and hydrogel caused greater losses of Ca, Mg and K in the leachate. The hydrogel increased the retention of Ca and Mg in the columns in all treatments, presenting higher values in the layers where limestone was applied. An irrigation blade of 630 mm with saline water (EC = 2.96 dS / m and RAS = 12) raises the pH of the soil, mainly of the superficial layers, with greater increases in treatments with limestone. The high concentrations of salts in the irrigation water (EC = 2.96 dS / m and RAS = 12) increases the levels of exchangeable Na in the soil profile, especially when they do not receive application of Ca sources. The application of gypsum may delay the deleterious effects of irrigation with saline water in an Argissolo Amarelo.