ABSTRACT

A study was carried out along a top sequence in lkwuano L.G.A of Abia State to evaluate the ef6cts of iron and aluminum oxides on soil structural stability. Five topounits; Crest (CT), Upper slope (US), Middle slope (MS), Lower slope and Valley bottom (VB) along the top sequence with an average of 150m apart were delineated and samples for analysis collected from Four depths of 0-15cm, 15-30cm, 30-45cm and 45-60cm using core samplers and auger. Samples were analyzed for soil properties namely: soil p1-I in water and KCI, organic carbon, available phosphorous, exe11am2,eal)le acidity, particle size distribution, hydraulic conductivity, aggregate stabiliy. and DCB extractable iron and aluminum oxides. Data f1oin the analysis were subjected to ANOVA using Split plot in RCBD. Results indicated that for both depths and l of sampling, the soil textural class ranged from loamy sand to sandy loan, while ph ratigecl from acidic to slightly acidic (4.5 — 5.0). Properties ;ach as Aggregate stability, Organic carbon , Hydraulic conductivity, j:\land Fe varied significantly with depth at a probability level ranging between 0.01 and 0.001 However along the top sequence, the Fe and Al oxides varied significantly at P<0.00 I . A simple correlation between Aggregate stability and [)CB Fe, DCB Al showed that ii was highly significant at a P<0.00 1. Also a simple positive correlation between DUB A! and Fe, and available P showed that it was non-significant. and %()C' the  1 While a negative correlation between AS% and OC%, DCB Al and OC%, DCB Fe and EA% showed that it was significant at l'KO.00.l but DC'B Fe and pH was non-significant.