Influência do Glifosato na sorção do fósforo em solos do Norte de Mato Grosso

Abstract

Glyphosate and phosphorus are widely required in the production of the main crops of the cerrado. These elements have the same retention mechanism in the soil and compete for the same sorption sites. Thus, this work aimed to analyze the relationship between the presence of glyphosate on sorption of phosphorus in a Entisol and in Oxisol. The tests were conducted in the laboratory of soils and vegetation of UFMT, Sinop -MT. It was the completely randomized design in factorial scheme 4 x 5 with three repetitions. The treatments corresponding to five doses of glyphosate (0; 2.5; 5; 25 and 50 L ha-1) and four doses (0, 30, 60 and 90 mg kg-1 in Entisol and 0, 140, 280 and 420 mg kg-1 in Oxisol). We evaluated phosphorus adsorption, adsorption capacity of P, energy and adsorption capacity factor of P Max. Influence of glyphosate on phosphate sorption in both Entisol and Oxisol. From the concentration of 90 mg kg-1 of phosphate in the Entisol, as it increases the dose of glyphosate gets greater the P sorption to soil colloids. In the Oxisol, in dose of 420 mg kg-1 of phosphate, with increasing dose of glyphosate, the smaller the sorption of P. The Entisol features smaller capacity in sipping the phosphate, as well as smaller binding energy.