Fertilização nitrogenada e orientação de plantio em palma forrageira

Abstract

This study aimed to evaluate the production of spineless cactus submitted to nitrogen fertilization and planting guidelines. The design used was a complete block randomized in factorial scheme of 5 x 2 (five doses of nitrogen - 0, 150, 300, 450, 600 kg of n ha-1 and two planting directions - east/west and north/south). The evaluations were performed on samples collected from the second year in palmal with annual cuts. For the morphological parameters, it was found nitrogen dose effect for the thickness of the secondary bud (P < 0,05), which showed quadratic effect with higher value at a dose of 300 kg of nitrogen ha-1 with 67,11% increase in relation to others not fertilized. For the variables areas of cladodes and cladodes numbers, there are no significant effects, independent of the cladodes order (P > 0,05). For plant height there was no effect (P < 0,05) to doses of 600 kg ha-1 with 22,35% increase compared to unfertilized plots. In relation to production of MS t ha-1 , there was no interaction (P > 0,05) in relation nitrogen levels x planting guidelines, with an average of 37,19 t de MS ha-1 year-1 . However, it was verified that the yield increased linearly with the increase of the doses. Thus, there was an increase of 40 kg ha-1 for each unit of N applied in the palmal. The marginal change with the application, the N between the highest and lowest dose was 103,15%. Regarding the chemical composition observed that the increasing of the N doses did not affect (P>0,05) the crude protein content. The increase in nitrogen levels until 600 kg ha-1 applied to the soil improves the production of biomass, the structural characteristics of the canopy and the nutritional value of spineless cactus cv. Giant and the planting guidelines little influence the nutritional value and mass production of the spineless cactus being recommended for the guidance of East/West planting.