CHEMICAL CHARACTERIZATION AND POTENTIALMINERALIZATION OF SELECTED TREE LEAVES IN THE GUINEA SAVANNA BELT OF NIGERIA

摘要

Some nutrient elements, trace metals and some chemical indices of mineralization which include total nitrogen, total organic carbon, phosphorus,lignin and tannin have been determined in the leaf prunings of Gmelina arborea, Vitellaria paradoxa, Tectona grandis, Entada africana, Prosopis africana, Parkia biglobosa, Leucaena leucocephala and Gliricidia sepium . The energy dispersive x-ray fluoresence analysis of V. paradoxa, G. sepium , P. africana and T .grandis showed that K, Ca and Fe were present as major elements(0.1 -1.0%). All the other metals including Mn, Ti, V, Cr, Co, Ni, Cu, Zn, Ta, W, Ga, As, Pb and Sr occurred at trace levels (0.1 – 0.001%) while the elements Se, Rb, Th, Y, U, Zr, Nb and Mo were present at ultra-trace levels (0.001-0.0001%). L. leucocephala has the highest indices for all the quality parameters and is expected to possess the highest degree of mineralization, while the leaves of V. paradoxa had the least values of quality parameters. In conclusion, L.leucocephala, G. sepium and G. arborea in the decreasing order, appear to possess high litter quality and therefore could be used as substitutes/suppliment for synthetic chemical fertilizer for the purpose of enhancing soil fertility.