CANOPY EFFECT OF Gmelina aborea AND Vitellaria paradoxa TREE SPECIES ON SOIL PROPERTIES

Abstract

The canopy effects of two tree species (Gmelina aborea and Vitellaria paradoxa) on soil properties was investigated in a southern Guinea area of Savannah ecosystem of Niger State, Nigeria. Soil samples were collected within the canopies of systematically selected Gmelina aborea and Vitellaria paradoxa trees and from adjacent open areas and analyzed. The result indicated that soils under the canopy had lower bulk density and higher porosity compared to the open area. The contents exchangeable bases, organic carbon, total nitrogen and available phosphorus were all higher under the two tree species compared to that of the open area. Amongst the two tree species, the soils under Vitellaria paradoxa had significantly lower bulk density, higher total porosity, moderately higher organic carbon and total nitrogen contents than soils under Gmelina aborea suggesting that inclusion of Gmelina aborea and Vitellaria paradoxa in the farming system by farmers in this area can likely improve soil productivity leading to lessening farmers’ dependence on mineral fertilizers.