Physico-chemical properties of soil polluted with petroleum crankcase oil and chlorophyll concentration of Abelmoschus esculentus (okra).

Effect of petroleum crankcase oil (PCO) on soil physico-chemical parameters and chlorophyll content of Abelmoschus esculentus (Okra) was investigated. Garden topsoil was collected from Obingwu, Ohii in Owerri West Local Government Area of Imo State, Nigeria tested for soil physico-chemical parameters, weighed and polluted with different volumes of PCO to give the various percentage pollutions. Five viable seeds of A. esculentus were planted in each. An unpolluted soil sample served as the control for the investigation. Harvest of the leaves and fruits was done immediately after fruiting and taken to the laboratory for the assessment of soil physico-chemical parameters and chlorophyll concentration. Results obtained for soil pH and soil phosphate show there was no significant difference (p>0.05) at the various levels of PCO pollution. However, there was a significant increase (p<0.05) in the percentage moisture content and calcium carbonate with respective increase in PCO pollution while a significant decrease (p<0.05) was observed in organic carbon, nitrogen and chlorophyll content of the PCO polluted samples when compared with the control. Furthermore, at 6% PCO pollution, only two seeds sprouted and leaf growth was not sustained till the end of the experiment. These results indicate that soil physico-chemical parameters and chlorophyll concentration of A. esculentus leaves were responsive to the detrimental effects of PCO in areas where it is disposed indiscriminately. Keywords: Abelmoschus esculentus, pollution, petroleum crankcase oil (PCO), soil, chlorophyll