Journal of Global Ecology and Environment

The study examined the effects of oil palm plantation on soil bio-physical properties in a part of the rainforest in Rivers State, Nigeria. Ten 20 m by 20 m quadrats were delineated in the oil palm plantation (OPP) and relatively disturbed forest (RDF) whereby soil samples were collected at the topsoil (0-15cm). Descriptive statistics were used to explain the means of the soil properties while Mann Whitney U (MWU) was used to test the variation in the soil properties between the OPP and RDF; and Spearman’s Rank correlation statistics were used to test the relationships between soil physical properties and biological properties. Findings showed that soil properties were higher in the RDF with the exception of soil moisture (16.0±5.16%), sand (88.40±1.03%), bulk density (1.49±0.01), electrical conductivity (342±176.3us/cm²), total feacal count (TFC) (2450000±2280959cfus/g), and total heterotrophic bacterial (THB) (1860000±2154169.08cfus/g). MWU analysis revealed that sand (z=3.87; p<0.05); clay (z=3.868; p<0.05); water holding capacity (z=1.930; p<0.05); soil pH (z=2.251; p<0.05) and organic carbon (z=2.307; p<0.05) were significantly different between OPP and RDF. However, findings showed that soil moisture content and soil pH were significantly correlated with TFC, THB and total fungal count. The study concluded that oil palm plantation has resulted to the depletion of the physical and biological properties of soil overtime. Thus, the study recommended among others that proper maintenance around oil palm plantation should be ensured to improve soil fertility within the plantation and sustain biological activities.