Acúmulo de macronutrientes no capim-elefante cv. Roxo em diferentes idades e épocas de crescimento

Abstract

The objective of this study was to evaluate the macronutrient uptake rate in elephantgrass cv. Managed under different ages and times of growth. A completely randomized design with split-plot arrangement with seven regrowth ages was adopted after standardization of elephantgrass cv. (9, 18, 27, 36, 45, 54 and 63 days) consisting of three seasons of evaluation (rainy, transition and dry), which consisted of subplots, and three Replications (plots of 3.0 x 3.5 m). The biomass was cut close to the soil, then fractionated, weighed and fed to the forced ventilation oven at 55 ºC for the determination of forage pre-dry biomass, whose fractions were compared by Tukey's test (P <0.05). During the experimental period, the development of plants and accumulation of macronutrients in purple elephantgrass were evaluated. Higher accumulations of macronutrients observed in the epochs were potassium (K), nitrogen (N) and phosphorus (P). The accumulation of N, P and K is most accentuated from 27 days in the rainy season. In the decreasing order of nutrients accumulated in all ages by elephant grass cv. Were K, N, P, magnesium (Mg), calcium (Ca) and sulfur (S). The distribution of fertilizer of 88.2 kg ha-1 of N and 219.00 kg ha-1 of K to the end of the rainy season is recommended for a greater nutrient accumulation for the period of 63 days.