Acúmulo de forragem em pastos de Tifton 85 adubados com nitrogênio e manejados sob lotação contínua

Abstract

The present study, carried out at the Division for Research and Development of Adamantina, SP/Brazil, at Agência Paulista de Tecnologia dos Agronegócios (APTA) – Polo da Alta Paulista, aimed to evaluate the effect of nitrogen fertilization on the morphological composition, tiller density, leaf area index, light interception and forage accumulation of Tifton 85 pastures subjected to continuous grazing. Treatments corresponded to three nitrogen and control doses (0, 100, 200 and 400 kg N/ha/year), arranged in a randomized block design with four replications. No effect of time of evaluation was verified on the vegetative, dead and total tiller densities of Tifton 85 under continuous grazing with variable stocking rate. The pastures of Cynodon cv. Tifton 85 were affected by the time of evaluation and nitrogen doses, with marked effect on the pasture morphological composition, leaf area index and light interception, which are determinant to forage accumulation. Tifton 85 grass reached the necessary conditions to achieve the maximum growth rate of the culture when managed under continuous grazing keeping the pasture at a height of 15 cm.