Influence of Palm Oil Mill Effluents on Selected Soil Physicochemical Properties and Soil Enzyme Activities

Abstract

Palm oil mill effluent (POME) is applied on cultivated farmlands at various stages by many farmers in

southeastern Nigeria with many reporting that it helps to improve crop yield and productivity despite no

availability of data to support their claims. This study was therefore designed to investigate the impact of

POME on soil physicochemical parameters and soil enzyme activities in soil samples from POME irrigated

farmlands. In this study, top and subsoil samples from control farmland unirrigated with POME, dumpsites

and 10 m away from POME dumpsites in six different farmlands irrigated with POME labelled A – F were

investigated using standard analytical procedures. The results of physicochemical properties of the soils

including nitrogen, phosphorus, organic carbon, organic matter, cation exchange capacity and exchangeable

cations indicated significant (P<0.05) in topsoil and sub-soils containing POME when compared with their

corresponding control1 soils. The lipase activities of topsoil from dumpsites A-E and subsoil 10m away from

dumpsite C indicated a significant increase (P<0.05) relative to the corresponding control soils. The effluents

caused a significant (P<0.05) decrease in the dehydrogenase and catalase activities of top-soils and sub-soils

from each of the dumpsites and 10m away from respective dumpsites when compared with their respective

control soils. The findings of this study revealed that the application of POME on soil increases the contents

of soil organic carbon, organic matter, exchangeable cations, and cation exchange capacity interfere with

enzyme activities.