CALCINED THERMOPHOSPHATE AND LIMED APPLIED TO Brachiaria GRASS IN SANDY LATOSSOL (Atena Editora)

Abstract

Within a cattle breeding system, food is one of the highest costs. Pastures present themselves as an alternative to providing food with adequate nutritional value in a more economical way to animals, however, for this to occur, the soil must be able to meet all the nutritional requirements of forage plants. The low availability of phosphorus in Brazilian soils has been one of the main limitations for the establishment of pastures, regardless of the forage species to be cultivated. The objective was to evaluate tillering (i) dry mass of leaves and roots (ii), gas exchange (iii) nutrient content (iv) of Brachiaria brizantha cv. Mg 5 as a function of calcined thermophosphates and liming. The experimental design used was completely randomized with 6 treatments and 3 replications, corresponding to powdered thermophosphate (with liming and without liming), crumbled thermophosphate (with liming and without liming), additional treatment with the use of super phosphate fertilizer and the control treatment, which consisted of soil without any type of management. Brachiaria brizantha plants were more sensitive to the absence of liming regardless of the type of thermophosphate powder or crumble. Tillering, leaf dry mass and gas exchange were affected by the absence of limestone, with this reduction being more evident with the use of crumbled thermophosphate, in the first and second growth. Powdered thermophosphate, when applied in combination with liming, promoted positive responses for tillering, dry mass of leaves, roots, gas exchange and nutritional contents for both growths.