Changes in Microbial Population of Palm Oil Mill Effluent Polluted Soil Amended with Chicken Droppings and Cow Dung

Abstract

Aim of Study: To assess changes in microbial population in palm oil mill effluent (POME) polluted soil amended with chicken droppings and cow dung. Study Design: 32 plots measuring 4 m2 were mapped out in a randomized complete block design of five main plots with three replicates. Data collected were subjected to ANOVA using SPSS. Place and Duration of Study: Faculty of Agriculture, Kogi State University, Anyigba, Kogi State, Nigeria: July 2011 to November 2011. Methodology: Plots were polluted with palm oil mill effluent and subsequently remedied using varying amounts of chicken droppings and cow dung (5 kg, 10 kg and 15 kg). Microbiological analysis was carried out using Nutrient agar and Sabouraud dextrose agar for the enumeration of total aerobic heterotrophic bacteria (TAHB) and fungi (moulds and yeasts) respectively. Results: Significant difference (P=0.05) in TAHB counts after 1 month and 2 months in all treatments with the exception of unamended polluted and unpolluted control soils. The counts however, increased after 2 months in all treatments with the exception of unamended polluted soil. The overall data suggest that amendment of the POME polluted soil enhanced microbial growth, particularly after 2 months meaning that bioremediation of the polluted soil can be achieved with the organic wastes within a short time. Conclusion: Chicken droppings (at 10 kg and 15 kg/4m2 plot) and a combination of chicken droppings and cow dung (at 10 kg and 15 kg/4m2 plot) have the ability to significantly increase microbial populations in palm oil mill effluent (POME) polluted soil thereby stimulating the bioremediation of the polluted soil.