Land Use System and Degradation Potential: Example from Brazil Amazon
*1,2 A. E. Ajayi, 1Martins, P. C. C., 1M. S. Dias Junior
1Department of Soil Science, Federal University of Lavras, Lavras- MG, (Brazil)
2Soil, Water and Environment Section, Department of Agricultural Engineering, Federal University of Technology, PMB 704, Akure, Ondo State, (Nigeria)
*Corresponding Author’s Email: firstname.lastname@example.org
Accepted on June 10, 2012
Inappropriate management techniques have been associated with some significant loss of agricultural land to degradation in many parts of the world. In this study, our objective is to evaluate the changes in structural attributes of a Cambisol soil structure under six different management practices using the load bearing capacity (LBC) models. Samples were collected from representative plot at 3 depths. The samples were analysed and subjected to uniaxial compression test to evaluate the effects on soil structure. Our result showed that the initial bulk density and porosity of the soil samples were not adequate to quantify structural degradation in Cambisol. In the topsoil we observed that pasture land use system was most severe in the degradation of the soil structure while the structure were most preserved in old secondary forest and cropping systems. At the subsoil level (10-13 cm depth), the soil structure was most degraded in the cropping land use system while it was most preserved in young secondary forest and pasture system. At the 20-23 cm depth, soil structure degradation was most severe in the old secondary forest system and well preserved in young secondary forest, cropping and agro forestry. Considering the soil structure degradation that was observed in virgin forest in the 20-23cm layer, and the 10 – 13 cm layer for re-forested farm, it is encouraged that researchers take a closer look on these land use systems, such that we can understand their contribution and dynamics in the estimation of global warming potential. Our conclusions in this study will be a good decision tool in the selection of system mix that could enhance continuous productivity on agricultural land in the sub-tropical and tropical regions of the world and particularly in the agricultural development process in the Amazonas agricultural belt in Brazil.