Saturated hydraulic conductivity and water-stable aggregates in some forest reserves of South western Nigeria

Abstract

A study was carried out along a toposequence in three forest reserves under Teak and Gmelina of Osun Grove, Onigambari, and Omo in south Western Nigeria to evaluate changes in saturated hydraulic conductivity (Ksat) and percent soil water-stable aggregates (WSA%). Three points: upper slope, middle slope, and lower slope were delineated and samples for soil analysis were collected from pedogenetic horizon using core samplers and auger. Samples were analyzed for soil properties like; Ksat and WSA (%) Data from the analysis were subjected to ANOVA using GenStat and means were separated using Duncan’s multiple range test at P <0.05. Results indicated that there were significant differences in the saturated hydraulic conductivity both under teak and Gmelina plantation along toposequence at Onigambari and Osun grove. But at area J4, upper slope subsurface soil under Gmelina plantation and lower slope surface soil were superior to other slope segments. Meanwhile, middle slope subsurface soil and upper slope surface soil under teak plantation were significantly different from other slope positions. The structural stability and erosion resistance of the soil in area J4 were higher than those of the soil in the Onigambari and Osun sacred grove.