Impact of Palm Oil Mill Effluent on Soil Microflora Dynamics in Bekwarra L.G.A, Cross River State, Nigeria

Abstract

Palm oil production generally requires large input of water which is eventually discharged indiscriminately untreated, posing threat to soil biota. This research aimed to investigate the impact of Palm Oil Mill Effluent (POME) on soil microflora dynamics in Bekwarra L.G.A, Cross Rivers State Nigeria. Eight control sites were initially identified, and soil samples were collected from each site before any intervention. Subsequently, effluent was dumped on the sites, and soil samples were collected at regular intervals of four weeks for the duration of sixteen weeks. The collected samples were analysed to assess changes in soil biota. A total of 32 samples were collected at different stages of sampling period. Data obtained were analysed statistically using the SPSS (20.0 version). At week 16, bacteria populations reduced drastically where Afrike had the highest (1.5 × 10⁸ cfu/g) while Abuochiche recorded the lowest (0.6 × 10⁸ cfu/g). A total of 93 bacteria isolates were identified where Pseudomonas was the most dominant (38.7%) across the study site per and it was followed by Micrococcus (19.4%).  In contrast, fungi count increased significantly at week 16 as the quantities of effluent on sites were high. Ukpah recorded the highest fungal count (4.8 × 10⁵ cfu/g while the least (2.9 × 10⁵ cfu/g) was recorded at Ibiaragidi. A total of 83 fungal isolates were recorded where Aspergillus was the most dominant (26.5%), followed by yeast (24.1%). The application of POME to the soil had a noticeable impact on the soil microbial community dynamics. The changes observed in the microbial population highlight the response of different microbial groups to POME, with bacteria exhibiting an early response while fungi showing a delayed but substantial increase. Further research is warranted to explore the specific mechanisms underlying these observed changes and their effects on soil health and ecological sustainability.