Gesso e rejeito de caulim na correção de um solo salinizado e no crescimento de gramíneas.

Abstract

Gypsum and kaolin tailings in the correction of a salinized soil and in the growth of grasses. The soils degraded by salts are frequent in arid and semi-arid areas and, specifically in Paraíba, are common in irrigated perimeters. There is a need to correct such soils and reintegrate them into agricultural productivity. Thus, the present work aims to evaluate the effect of correctives and select more tolerant plants in the process of recovering salinized soils. In a first step, gypsum and mining waste were applied to the soil and the amount of salts and sodium leached was evaluated. In the next phase, the growth and production of sorghum millet, urocloa and buffel species were tested in the treatments: non-saline soil, salinized soil, salinized soil plus gypsum and salinized soil plus tailings. At first the soil was kept moist and then soil samples were collected for the determination of pH, Na and electrical conductivity. After sowing, weekly measurements of plant height were performed and, at the end of the experiment, biomass production was quantified. The results showed that agricultural gypsum provided a greater removal of soluble salts and exchangeable sodium from the soil, and greater plant growth and production, mainly of millet and sorghum grasses, respectively.