Aerial and root mass in Leucaena leucocephala L. grown in nursery with nitrogen and phosphate fertilization

Abstract

The objective of the study was to determine above and below ground biomass in Leucaena at different rates of N and P fertilization (0, 25 and 50 kg ha-1 for both elements) in a 3 x 3 factorial arrangement. The experimental design was a completely randomized with 10 replications and the experimental unit was one plant. Fertilization was applied at 80 d and measurements taken at 148 d after the emergence of the first true leaf. Within the first 15 days after fertilization all plants receiving the rate of 50 kg of N ha-1 died, thus the statistical analysis was applied to a 2 x 3 factorial, with two levels of N (0 and 25 kg ha-1) and the three of P. The interaction NXP was not significant (P >0.05) in any of the variables measured. Application of N reduced (P <0.05) root weight, volume, and length and stem weight by 20 to 36%, and increased leaf to stem ratio without effect on leaf weight (P < 0.05). Plants without N showed up to 54 root nodules, and plants with N none. Application of P caused reduction (P < 0.05) of root volume and stem weight increased leaf to stem ratio without effect (P >0.05) on nodulation. The aerial and root biomass of Leucaena in the nursery stage did not benefit from N and P fertilization.