Atributos químicos de um latossolo vermelho eutroférrico submetido a gessagem e cultivado com trigo e soja em semeadura direta

Abstract

The presence of aluminum in the soil is one among the several existent problems that harm the growth, development and productivity in commercial cultures as soy and wheat principally when water deficit, once there is minor surface of roots for the absorption of water. Like this the influence of the use of the plaster was analyzed in the chemical characteristics of a Latossolo vermelho eutroférrico of loamy texture for the wheat cultures and soy, under system of direct planting. It took place collections of soil samples to the six and 12 months after application 0, 1, 2, 3, 4 e 5 t ha-1 of the gypsum to evaluate the tenors of Ca, Mg, K, exchangeable Al, pH, SB, V%, m% and tenor of S in the soil. For the wheat cultures and soy they were appraised the tenors of Ca, Mg, K, S, and Al in the tissue, mass of 1000 grains and productivity. The use of gypsum increased the tenors of Ca and S and it reduced Al's tenors, besides leaching Mg and K in the soil, increasing SB and V% in the deepest layers. In the tissue increased Ca and Mg for the soy and it reduced in the wheat, it increased the tenor of S in both cultures and K increased in a quadratic way for the culture of the soy. The found results show that the use of the plaster provided mobility of K+ and Mg2+ up to 40 cm of depth. The use of up to 5 t ha-1 of gypsum they resulted in increase of the tenors of Ca2+ and SO42 - in depth until one year after the application and the dose of 3 t ha-1 it provided larger reduction of exchangeable Al and also of the saturation for Al for Latossolo vermelho eutroférrico of loamy texture. In exchangeable Al's presence the use of the gypsum implicated in increase of the wheat productivity but it didn't influence the productivity of the soy