The Impact of Cassava Effluent on the Microbial and Physicochemical Characteristics on Soil Dynamics and Structure

The effects of cassava effluent on soil microbial and physicochemical properties were studied using culture-dependent and standard analytical methods. Soil samples were collected from sites polluted with cassava effluent and from adjacent sites that were not impacted with the effluent pollution. The isolation and enumeration of microbial population was carried out using standard culture-based methods. Standard analytical methods were used to assay for physicochemical properties. The highest bacterial count of 3.61×10^8 ± 0.12 CFU/g was recorded for polluted soil sampled from Ehor, while the lowest count of 1.3×10^8 ± 0.03 CFU/g was recorded in Isihor. Isihor had the highest fungal count of 2.2 ×10^8 ± 0.01 CFU/g from soil contaminated with cassava effluent. The fungal counts of the polluted soil were significantly lower than the bacterial counts generally (p 0.05). The heavy metal contents of the contaminated soils were relatively higher than the uncontaminated soil (control). Unlike in the control soils, pH of the polluted soils ranged from 4.0 - 4.78. The bacteria isolated were Bacillus subtilis, Bacillus macerans, Pseudomonas aeruginosa, Klebsiella aoxytoca and Escherichia coli. Eleven species of fungi belonging to the genera Aspergillus, Penicillium and Rhizopus were also isolated. The present study shows that the cassava effluent can have an increasing or limiting effect on the microbial diversity of the polluted soil which could also be attributed to the simultaneous impact on the physicochemical parameters of the soil.