Respostas produtivas e qualitativas de leguminosas forrageiras sob diferentes sistemas de cultivo

Abstract

Considering the morphological variability of tropical forage legumes, it is important to study their productive aspects and nutritive value under different conditions of cutting management or cropping systems. In this sense, two experiments were carried out at Carpina, Pernambuco, Brazil. In the first one, the objective was to evaluate the nutritive value of stylo cv. campo grande (Stylosanthes capitata Vog. × Stylosanthes macrocephala M. B. Ferr. & N. S. Costa), butterfly pea (Clitoria ternatea L.) and ‘jureminha’ [Desmanthus pernambucanus (L.) Thellung] under harvesting frequencies of 60 and 90 days. Experimental design occurred under complete randomized blocks and a split-plot arrangement, with four repetitions. Greater CP contents (p<0.05) were observed in leaves of butterfly pea and jureminha (233 and 219 g kg-1 DM, respectively), as well as the stems from butterfly pea and stylo cv. Campo Grande (75 and 74 g kg-1 DM). Just the CP contents in stems were affected by the harvesting frequency (p<0.05), and greater values were observed in the 60-day frequency. Greater indigestible fractions (p<0.05), both in carbohydrates (259 g kg-1 TC) and proteins, were observed in jureminha leaves harvested at 60 or 90 days (139 and 136 g kg-1 CP, respectively). Butterfly pea and stylo cv. campo grande are promisors to be included in different forage production systems. In the second experiment, the objective was to evaluate both the productivity and nutritive value of butterfly pea intercropped with elephant grass genotypes (Cenchrus purpureus Schum.) that had different sizes. Experiment was carried out through a randomized complete blocks design with four repetitions. Greater contents of PB were verified when the legume was managed jointly with the tall clones, Elephant B and IRI-381 (187 and 174 g kg-1, respectively). Butterfly pea digestibility stood out in the consortiums with Elephant B, IRI-381 and Taiwan A-146 2.37 (607, 608 and 584 g kg-1, respectively). Although the genotypes did not affect the butterfly pea in most of the studied variables, the significant effects occurred in essential characteristics of forage quality, which indicates that the butterfly pea consortiums with IRI-381 and Elephant B genotypes are better indicated to improve the diet quality for animals.