Diferimento capim-paiaguás com distintas alturas e doses de nitrogênio

Abstract

Deferring the use of pastures is a relatively easy alternative, using little labor in its implementation and lower operational production cost to supply food to ruminants in the period of forage scarcity. This management strategy can be enhanced through nitrogen fertilization and lowering of pasture at the beginning of the deferral. However, the knowledge about the use of grass-paiaguás for this purpose is still incipient. Thus, this study was carried out with the objective of evaluating the productive and structural characteristics of the paiaguás grass (Brachiaria brizantha cv. BRS Paiaguás syn. Urochloa brizantha cv. BRS Paiaguás) deferred with different initial heights and nitrogen doses. The experiment was conducted between August 1 and November 1, 2020, totaling 90 days. Four nitrogen doses (0, 40, 80 and 120 kg / ha of N) associated with two initial canopy heights at the beginning of the deferral (15 and 30 cm) were evaluated. The experimental design was a block, in a factorial scheme, with three replications, totaling 24 experimental units. The increase in the nitrogen dose reduced the population densities of aerial tillers, as well as decreased the population densities of tillers with sizes from 0 to 10, 10 to 20, 20 to 30 and 40 to 50 cm. There was no reproductive tillering. The increase in the nitrogen dose linearly increased the masses and the accumulation of total forage, leaf blades, live stalk and dead forage. Paiaguás grass deferred with 30 cm and 120 kg / ha of N has a larger size, forage mass and forage accumulation.