Forestry covers and fertility recover in Ferrallitic Soils from Angola

Abstract

Effects of different forestry covers - “mata de panda” (MP), Pinuspatula (PP)Eucalyptus grandis(EG) andGrevillearobusta (GR) - installed between 1965 and 1968 in the Estação Experimental Agrícola da Chianga(Huambo, Angola), on chemical properties of Ferrallitic Soilswere assessed up to 30 cm depth, as compared to those observed in nearby conventional agricultural fields.Only the soils of the areas with EG and GR showed a clear improvement in their reaction, content of organic carbon and of extractable non-acid cationsand effective cation exchange capacity, usuallyup to 10 cm depth. The improvement associated with “mata de panda”was less pronounced and that of PP plantations was negligible or nil.The recover capacity of soil fertility may depend on the nature of tree cover as well as on the soil characteristics itself. Results also indicate that the low soil capacity to retain cations exhibited by soils of the Planalto Central of Angola can be increased through both acidity correctionand increasingthe content of soil organic matter.