Crescimento e produtividade de palma forrageira sob diferentes lâminas de irrigação e adubação nitrogenada.

Abstract

The palm is one of the main forages used in animal nutrition in the Brazilian Northeastern semiarid region, besides being an innovative source for the production of biofuel. The objective of this study was to evaluate the performance of forage palm under different irriga tion and nitrogen fertilization. The experiment was conducted under field conditions in the Municipality of Santa Luzia - PB, at the Poço Redondo farm. The experimental design was a randomized complete block design in a 5 x 5 factorial scheme, consisting of five irrigation slides (125, 100, 75, 50 and 25% of ET0), five levels of nitrogen fertilization (0, 150, 300, 450 e 600 kg ha-1 of N), with three replicates, totaling 75 experimental units. Number, length, width and thickness of cladodes, plant height and width, absolute and relative growth rates, area and cladode area index, cladode green biomass, estimated non-destructive and destructive productivity were evaluated throughout the experiment and efficiency of forage palm water use. The data were analyzed by the F test and polynomial regression analysis. The irrigation blade significantly influenced the growth variables of the forage palm studied, except for the number of cladodes. The different doses of nitrogen fertilization, applied via fertigation, significantly influenced the growth variables of the forage palm, except for the length and the cladode area. The highest estimated non destructive, destructive and maximum efficiency of the use of forage palm water for cultivating Mexican elephant ear were obtained in the association of irrigation depth of 125% of ET 0, total of (371.09 mm) and nitrogen dose of 600 kg ha-1. In semiarid conditions with average temperature of 27.6 ° C the forage palm responds to both irrigation and nitrogen fertilization. It is recommended the cutting of the forage palm twice a year, when submitted to nitrogen fertilization and irrigation.