The effect of crude impacted soil on the biochemical properties of guinea corn

Abstract

This study investigated the effect of crude oil impacted soil on physiomorphological and biochemical properties of guinea corn (Sorghum vulgare). Thirty polythene pots with drainage holes at the bottom, each containing 10 kg of surface soil, were randomly placed on a table in a screenhouse in a factorial combination of five treatment levels (0.4%, 0.3%, 0.2%, 0.1% and 0%w/w) of crude oil. The soil inside the pots was homogenized by stirring using a glass rod, wetted with distilled water and allowed to equilibrate for two weeks. Two weeks after the application of crude oil, three seeds of guinea corn per pot were planted. Result revealed a significant decrease (p<0.05) in girth length of Guinea corn planted in crude oil-impacted soil relative to the control. The relative water content RWC ranged between 80% and 87%. Generally, activities of the antioxidant enzymes of leaves and stems of Guinea corn planted in crude oil-impacted soil increased significantly relative to the control (p<0.05). The soluble protein content (SPC) of the leaf of Guinea corn in P0.4 was less than 1⁄2 that of the control. Conversely, the malondialdehyde (MDA) of the leaf of Guinea corn in P0.4 was about 1 1⁄2 folds that of the control. The estimation of antioxidative enzymes and non-enzymatic antioxidative parameters after
contamination with higher level of crude oil has shown that the defence mechanism of the plant against the toxic influence of the crude oil is overwhelmed and hence predisposed to oxidative stress. No spill should, therefore, be taken for granted. Crude oil-impacted soil induced a condition of oxidative stress in guinea corn, which could in turn be transferred to the consumer.