Physicochemical changes in maize plant (Zea mays) grown on contaminated soil exposed to sawdust treatment

Abstract

The potential effects of sawdust for bioremediation of growing maize grown on crude oil contaminated soil was evaluated in this study. The experiment was divided into 3 groups control (soil without crude oil), polluted (soil with varying concentrations of crude oil), and sawdust treated (polluted soil with 50g sawdusts). The polluted and sawdust treated regime received four levels of treatments with crude oil (25g, 50g, 75g and 100g). Viable seeds of maize were grown on the soil beds for 35 days to assess the % germination, % survival, stem height, chlorophyll a and b, oxidative stress indicators and selected macronutrients using standard methods. Data obtained shows that the growth performance of the sawdust treated samples containing low concentration of crude oil was better in comparison to polluted groups but less than that of control. Sawdust remediation helped in overcoming the growth inhibition due to pollution to some extent. Significant increase (p<0.001) in the activity of antioxidant enzymes (superoxide dismutase, catalase and peroxidase) were observed in the sawdust treated regime when compared with the polluted and control groups. The result also showed a significant decrease (p<0.001) in Malondialdehyde levels and a non- significant increase (p>0.05) in macronutrients assessed in the remediated regime when compared with the polluted regime. Remediation of the polluted soil with sawdust relieved the inhibitory effect of crude oil on the plant growth particularly in groups containing lower concentrations of crude oil.

Keywords: crude oil, sawdust, antioxidants, oxidative stress