The fixed nitrogen may compete for oxygen in the rhizosphere leading to release of toxic materials [41] and [42]For a compost to be used as a growth medium its C/N ratio should be between 12 and 18 [40] and [43]; however, a C/N ratio of 20 may be acceptable [39] and [42]. In this study, the C/N value of 10.1 ± 3.0 obtained was close to the suggested values required for agricultural purposes .Addition of compost to the contaminated soil samples resulted into higher values of C/N ratios in the two treatments. Generally, the value of C/N ratio less than 15.0 in compost will lead to rapid mineralization and increase in nitrogen contents of soil [44]. The C/N ratio of the finished compost was also similar to the value of 10.1 calculated in the vermin-compost used for phytoremediation experiment by Jadia et al. [11]. Addition of compost increased nitrogen concentrations from 0.86 ± 1.50% to 1.87 ± 1.07% in ‘compost-only’ treated soil and 1.65 ± 0.74% in ‘compost + plant’ treatments.