Forage accumulation, chemical composition and macronutrient extraction of Trachypogon plumosus pastures intercropping with Stylosanthes capitata cv. Lavradeiro under phosphate fertilization

Abstract

Was evaluated the effect of phosphate fertilization (0, 40, 80 and 120 kg of P2O5 ha-1) on the forage yield, chemical composition and macronutrients extraction of Trachypogon plumosus native pastures intercropping with Stylosanthes capitata cv. Lavradeiro in Roraima´s savannas. The effects of phosphate fertilization on forage yield of grass and legume were quadratic and the maximum yields estimated with the application of 81.9 and 106.7 kg of P2O5 ha-1, respectively. Nitrogen, calcium, magnesium and potassium contents and extraction of grass and legume were quadratically affected by phosphate fertilization, while for phosphorus the relationship was linear and positive. Macronutrient extractions by grass and legume, independently of phosphate fertilization, were higher for N and K, followed by Ca, Mg and P. Phosphate fertilization provided grass and legume forage with better quality and lower fiber contents. Considering the overall availability of forage and pasture botanical composition - satisfactory grass/legume relationship - the use of phosphorus levels between 80 and 100 kg of P2O5 ha-1 allow the establishment and yield stability and persistence of grass-legume mixture.