Characterization and pedogenetic study of soils of Onigambari Forest Reserve in South-West Nigeria

Abstract

The use of forest resources requires accurate knowledge of land and soil properties. This necessitates detailed soil description and classification. This study was conducted to characterize and classify pedogenesis of Onigambari Forest Reserves in south-west Nigeria. A standard flexible rigidgrid method of survey was used to establish the mapping units. Three profile pits were dug under each land use type (Teak and Gmelina plantations), making six pits in the location. The profile pits were sampled at the pedogenic horizons for physical and chemical properties analyses. Soils obtained were classified using standard methods. The soils were classified as order Alfisols. Based on the moisture regimes, the soil belongs to Udalfs and Aqualfs suborder. At the great group level, the soil fell into the Kandic horizon. Under teak plantation, pedons 1 and 2 were classified as Plinthic Kandiudalfs (Eutric Lixisols), pedon 3 as Arenic Kandiaqualfs (Gleyic Lixisols) while under Gmelina, pedon 4 was classified as Typic Hapludalfs (Ferric Lixisols), pedon 5 Typic Kandiudalfs (EutricLixisols) and pedon 6 TypicKanhapluaqualfs (Gleyic Lixisols). At the soil series levels, pedons 1, 2, 4 and 5 belonged to Gambari series, pedons 3 and 6 belonged to Apomu series. Pedogenic processes identified were leaching, plinthization and desilication processes.