Effects of soil treatment with abattoir effluent on morphological and biochemical profiles of cowpea seedlings (V.unguiculata) grown in gasoline polluted soil

Abstract

The effects of abattoir wastewater treated soil on morphological and biochemical profiles of cowpea seedlings (Vigna unguiculata) grown in gasoline polluted soil was studied. Percentage germination, shoot length, root length and leaf area of cowpea seedlings grown in gasoline treated soil decreased significantly (P < 0.05) when compared to the control. Moreover, gasoline contaminated soil significantly (p<0.05) decreased levels of total sugar, total protein, total amino acids, total chlorophyll, chlorophyll a and b, and β-carotene contents of the leaves as well as significant (p<0.05) decrease in the activities of α-amylase and starch phosphorylase in the cotyledon compared to seedlings in the control. Cowpea seedlings grown in gasoline contaminated soil also showed alterations in antioxidant enzymes when compared to the control. However, treatment of gasoline contaminated soils with abattoir wastewater (AWW) substantially improved the growth parameters, chlorophyll and β-carotene contents of the cowpea seedlings. The activities of α-amylase and starch phosphorylase, in addition to the antioxidant enzymes were considerably enhanced by AWW treatment. These findings showed in clear terms that abattoir wastewater may be a suitable manorial material for remediating gasoline contaminated soils as well as mitigate toxic effects of gasoline on exposed plants.

Keywords: Abattoir, Cowpea, Amylase, Phosphorylase, Antioxidants