The impact of cassava mill effluent on the total aerobic bioload and physicochemical properties of the soil

The impact of cassava mill effluent on total aerobic bioload and physicochemical properties of soil was determined. Soil samples were collected with sterile soil auger and subjected to standard microbiological analysis. The results revealed significant differences (P<0.01) in total aerobic bacterial counts between the impacted samples (2.0x106 ±0.87cfu/g and 4.7x106 ±1.56cfu/g) collected 5 and 50m away from the mill and the control sample (4.7x106±1.56cfu/g) collected 50m before the mill. Samples collected 50m before and after the mill recorded no significant difference in bacterial counts. There was no significant difference in total fungal counts recorded at various distances before and after the mill. The pH values of the impacted samples were acidic, recording 4.81 and 6.31 at 5 and 50m away from the mill, while the control recorded 7.6. Impacted samples also recorded higher hydrogen cyanide contents (12.4 and 9.17) than the control (6.8). The C/N ratios of the impacted samples (9.10 and 6.73) were smaller than the control (14.60). The Effective Cation Exchange Capacity of the samples equally followed the same trend. Cassava mill effluent has therefore impacted negatively on the microbial counts and physicochemical properties of the soil.