Produção de biomassa, de açúcar e de proteína em função de variedades de cana e de adubação fosfatada

Abstract

The sugarcane is a fodder that presents nutritional limitations, due to low levels of protein, phosphorus and sulfur; however, the phosphorous fertilization can improve its nutritional quality, because it influences in the absorption and the metabolism of nitrogen and phosphorus. In this study, the accumulation of dry substance from phosphorus and raw protein and the production of sucrose from two sugarcane varieties in function of the phosphorous fertilization in the sugarcane – plant cycle were evaluated. The study was a 2 x 6 factorial, consisted of two sugarcane varieties, RB867515 and RB92579, and six doses of phosphorus: zero, 30, 60, 90, 120 and 150 kg ha-1 of P, with treatments distributed in blocks at random, with five repetitions. Nitrogen and potassium fertilization in doses equivalent to 100 and 200 kg ha-1 of N and K were also used respectively. The phosphorous fertilization influenced in the accumulation of dry substance and sucrose, having a quadratic effect. There was a linear effect, but discrete, of the doses of P on the concentration of this element in the dry substance, which was not observed for the raw protein concentration. On the other hand, the protein and phosphorus mass were significantly influenced by the fertilization.