Economic viability of production of Nellore heifers on Urochloa brizantha cv. Marandu pastures deferred and fertilized with nitrogen

摘要

The objective of this study was to evaluate the effect of different levels of nitrogen on deferred pastures of Urochloa brizantha cv. Marandu, and the implications on the economic viability of production of Nellore heifers. This was a completely randomized design with four treatments (T1 = deferred pasture without nitrogen fertilization; T2 = deferred pasture fertilized with 50 kg N ha -1 , T3 = deferred pasture with 100 kg N ha -1 , T4 = deferred pasture with 150 kg N ha -1) and four replications (16 fertilized paddocks). First, there were used 48 Nellore heifers, average eight months of age and initial body weight of 178.69 ?± 26.67 kg, with three heifers in each paddock, in all treatments, in a continuous grazing system, with variable stocking rate. Only the treatment the without nitrogen fertilization showed negative monetary values of R$ -181.96, R$ ha -1 -72.79 and R$ @ -1 -32.11. The treatment with 50 kg N ha -1 achieved the highest positive monetary values of R$ 756.02, R$ ha -1 302.40 and R$ @ -1 50.52. Economic viability data in beef heifer production demonstrate that the treatment with 50 kg N ha -1 is the most financially viable under the conditions of this study.