Frações de fósforo em gramíneas forrageiras tropicais sob fontes e doses de fósforo

Abstract

The work was carried out with the objective to determinate fractions of phosphorus (P) in the tropical forage grasses, at 35 days of age, submitted to sources and doses of P. The experimental design was a randomized complete block, in split split plot scheme, with three repetitions, being allocated in the plot the grasses (coastcross bermudagrass, florona stargrass and kikuyu grass); in the subplot the sources of P (Triple superphosphate; Reactive phosphate, Arad and Nature phosphate, Araxa) and, in the subsubplot, the doses of P (0, 40, 80 and 120 kg/ha of P2O5). The studied variables were soluble total P- Pt, inorganic P- Pi and organic P- Po. The kikuyu grass shown lower (P<0.01) concentration of inorganic P (322 µg/g) that the coastcross bermudagrass (244 µg/g) and the florona stargrass (235 µg/g). However, the coastcross bermudagrass shown larger concentration of soluble total P than the florona stargrass and kikuyu grass, being observed values of 589, 442 and 492 µg/g, respectively.