CARACTERÍSTICAS PRODUTIVAS E NUTRICIONAIS DO ESTILOSANTES CAMPO GRANDE SUBMETIDO A INTERVALOS DE CORTES E ADUBAÇÃO FOSFATADA

Abstract

The objective of this study was to evaluate the productive and nutritional characteristics of the Campo Grande estilosantes submitted to intervals of cuts and phosphate fertilization. This work was carried out in a greenhouse, with pots of 6 dm³ of soil, from December 2017 to April 2018, in 4×3 factorial, with four levels of P2O5 (0; 100; 200 e 300 kg/ha) and three cut intervals (40; 60 and 120 days), in a completely randomized design with four replications. Plant biomass and root production per hectare were evaluated, structural characteristics such as height, number of leaves, leaf:stem ratio, root length and number of nodules; and chemical-bromatological composition of the leaf, stem, and total aerial part. The analysis of variance and regression of the data were performed by the Tukey test (P<0,05). The total dry matter yield of the aerial part per hectare (PMST) was significant at the interaction (P<0,05) only in the cut interval at 120 days, in quadratic adjustment, with a maximum at 136,18 kg/ha of P2O5, for PMST of 8093,95 kg/ha. In general, plant height (AP) and stem diameter (DC) were higher in the 120 day interval, with 55,71cm and 3,53mm, respectively. Conversely, the leaf: stem ratio (F:C) was higher in the 40 day interval, with a value of 2,08; the number of nodules (NN) presented a significant effect (P<0,05) of the fertilization, in the interval of 120 days, in quadratic adjustment, with a higher value, at a maximum dose of 173 kg/ha of P2O5. There was no effect of fertilization (P>0,05) for NDF, ADF and HEM, leaf, stem and total shoot. There was an effect (P<0,05) of the fertilization, on the PBF and PBT levels, with maximum levels of 20,43 and 16,44%, respectively, with fertilization below 190 kg/ha of P2O5. Under the conditions of this study, aiming at a higher nutritional value, the management of the Campo Grande estilosantes under the 40 day cut interval, with a phosphate fertilization level of up to 100 kg/ha of P2O5 is the most efficient. Since the purpose of this legume is to recover degraded pasture areas and compacted soils, the cut-off interval of 120 days is recommended, without prejudice to voluntary ingestion in case of grazing.