Adubaçao Nitrogenada do Capim-elefante cv. Mott. 2. Valor Nutritivo ao Atingir 80 e 120 cm de Altura

Abstract

This trial was carried out, from October 1993 until June 1995, to evaluate the chemical composition and dry matter digestibility of dwarf elephantgrass at plant heights of 80 and 120 cm under five nitrogen rates. The experimental design was completely randomized with a split split plot arrangement, with four replicates, where the clipping factors, and nitrogen doses (0, 25, 50, 100kg/ ha•clipping, in the first year, and 0, 75 and 100 kg ha•clipping, in the second year, and plant heights (80 and 120 cm) and its effects on the grass performance to yield were studied. The crude protein content in the leaf blades ranged, in the first year, from 8.8 to 13.2, in plants that reached 80 cm, and from 9.7 to 11,3% in plants with 120 cm, and in average, from 9.6 to 12.6%, in the second year, in response to the doses of nitrogen. The neutral detergent fiber, that was of 71.7% in the first year, varied from 67.4 to 71.1%, in plants with 80 and 120 cm, respectively, in the second year. The observed coefficients of IVDMD were 66.3 and 64.9% for plant heights of 80 and 120 cm, in the first year, and 69.0 and 61.5, in the second year, in the leaf blades of plants with 80 and 120 cm, respectively. The P, K and Ca contents in the leaf blade inversely varied with the nitrogen doses, while the Mg content did not present variation.