Profile Distribution of Physical and Chemical Properties in Soils of a Toposequence in Benin, Rainforest of Nigeria

The experiment was carried out along a toposequence to study some physical and chemical properties of soils from three pedons at three topographic positions representing, Rhodic Paleuults (pedon 1) in the Upper Slope (US), Typic Udipsamment (pedon 2) in the Middle slope (MS) and Typic Psammaquents (pedon 3) in the Bottomland (BL). Soil samples collected were analyzed for pH, organic carbon content, total nitrogen, available phosphorus, exchangeable cations (Ca, Mg, Na and K) and particle size distribution. The trend of change and difference in soil properties down the profiles and across the landscapes position were also studied. Results showed that BL had the highest organic carbon content with a range values of (6.00 – 30.30g/kg ) and US had the lowest organic carbon content (5.40 - 9.70g/kg). The variation of the soil chemical properties showed that available phosphorus varied highly across the landscape with MS having highest P value of 14.72mg/kg and highest CV of 137.47%. CEC is low across the landscape, The trend of change and difference in soil properties across the slope shows that soil properties differs at these three positions, it was observed that soils of the bottomland were more fertile than those of the Upper slope. The results generated in this study could provide useful information for effective land use planning and land management.