Avaliação nutricional e de crescimento incial em altura de espécies arbóreas em sistemas agroflorestais na região de Itaparica, semiárido pernambucano

Abstract

This study developed at the Experimental IPA station in Belém de São Francisco - PE, surrounding the Itaparica Reservoir, in Pernambuco semiarid zone, aimed to evaluate the effect of using sediments from Itaparica reservoir and fish pond waste as organic fertilizers and biochar as a soil conditioner and the effect of two spacings, 3 x 2 m and 4 x 2 m, in stimulating the growth of four tree species: two Eucalyptus clones (Eucalytpus urophylla x Eucalytpus tereticornis) angico (Anadenanthera colubrina var. cebil) and aroeira (Myracrodruon urundeuva Allemão), associated or not in agroforestry systems with cowpea and in a silvopastoral system with Tanzania grass. It was used a multivariate statistical method of repeated measures over the time. Measurements were taken every three months after planting (0, 3, 6, 9, 12, 15 and 18 months) in the useful area of the plots (10 plants). The number of permanent plots was 256, distributed in a randomized pattern, with four repetitions, which included control without fertilization and isolated plantations. The two spacing were 4 x 2 m for tree species in the consortium and isolated and 3 x 2 m for the species forest isolated. it was collected samples of leaves for foliar analysis in newly mature harvested from the middle third of the canopy, to determine the nutritional status of four tree species, adopting a completely randomized design in a factorial arrangement 4 x 4 x 2, for the isolated and consortium plantation. The fertilization of the species with organic sources of nutrients at the time and after planting resulted in better growth of tree species and improved the nutritional status of the species, especially in relation to nitrogen. The residues from fish farms ponds and lake sediments appear as good alternatives to fertilization in agroforestry systems, as well as in forestry and agriculture. The smallest spacing (3m x 2m) resulted in higher growth of forest species. Native species (angico and aroeira) appeared to have higher nutritional requirement and, in general, had higher levels of nutrients in the leaves compared to Eucalyptus clones. The nutritional content found in leaves, in different spacing and consontium for angico, aroeira and the clone MA 2000 followed the decreasing order: N> Ca> P> Mg and for clone MA 2001 the sequence was N> Ca> Mg> P. For the different consortia, the sequence for all the species was N> Ca> P> Mg. Consortia with agricultural species and the forage species did not affect height growth of forest species and added value to forest production.