Resposta de um campo nativo adubado e simulação de alternativas de sistemas com base nessa tecnologia

Abstract

Was used five excluded parcels from the grazing with electric fence help, being: T0 – Control treatment, T1 – Native pasture with application of 2 ton./ha of limestone (T1), T2 – native pasture with application of 100 kg of fertilizer, T3 – native pasture with application of 200 kg of fertilizer and T4 – native pasture with application of 300 kg of fertilizer, the formulate of utilized fertilizer was composite by 2% of N, 23% of P2O5 and 23% of k20. Was realized five evaluations of grazing, taking of samples, in with after dry in kiln, was estimated the dry matter (MS). To the curve of annual pasture production evaluation, was collected data from works performed in state of Rio Grande do Sul, after compared with the estimative of growth of treatments, watching the effect of fertilization in relation to the mean production in state. To evalue the production potential form different fertilizations was realized one simulation in scene to rearing of heifers, from the utilization of evolution of the herd worksheets, of wich in any treatment in simulation represents an area of 50 ha and, from the data of dry matter and disponibility and the tax of estimated daily growth, was calculated the capacity of support of each treatment and the average gain in weight by area according to the average daily support weight gain stipulated to the animals . The disponibility of dry matter presents significant difference (P>0,05), where T1 was inferior to other treatments in February month and in April month where t3 was superior to the others. The others herd simulations showed be possible work with medium load of 329,5, 317,3, 390,6, 432,4 and 471,6 kg/ha to T0, T1, T2, T3 and T4, respectively. The gains in kg of of PV/ha not showed answer to liming, but showed crescent answer according with the liming doses, with means of 16,20, 18,08 and 19,21 kg of PV/ha, respectively, and 13,79 kg of PV/ha to T0.