Chemical composition and salinity of leachate in two soils cultivated with onion irrigated with saline water

Abstract

Aiming to evaluate leachate chemical composition and salinity from two Fluvic Entisols of Pernambuco-Brazil, cultivated with onions irrigated with saline water, an experiment was carried out in random blocks, in a factorial arrange 2 x 3 x 6 (two soil types – silty clay loam and sandy loam –, three levels of electrical conductivity - 200, 700 and 2.000 ìS cm^-1 and six levels of sodium adsorption ratio - 0, 5, 10, 15, 20 and 25 (mmolc L^-1)^1/2), with four repetitions. After 30, 60 e 90 days of the transplanting the leached from the pots was collected for composition evaluation. Levels of cation, chlorine, electrical conductivity and leachate sodium adsorption ratio, collected at 30, 60 and 90 days after transplanting, with increasing salinity of irrigation water, were
observed. Only 90 days after transplanting, the leachate from the soil of silty clay loam texture surpassed the levels of cation and chloride compared to leachate from sandy loam soil. Thus, more saline irrigation water promotes greater lose of elements in the soil because of their removal, which occur more slowly in soils of thinner texture.