Effect of oil palm leaf treatment of crude oil impinged soil on biochemical indices of cowpea (vigna unguiculata) seedlings

Abstract

The possibility of oil palm leaf (OPL) being applied as ameliorative agent in unrefined petroleum oil tainted soil was examined in this study. Six treatment protocols, comprising group 1 (untainted soil), group 2 (untainted soil +50g of OPL), group 3 (untainted soil +100g of OPL), group 4 (petroleum oil tainted soil), group 5 (petroleum oil tainted soil +50g of OPL) and group 6 (petroleum tainted soil +100g of OPL) were used in this study. A decrease in photosynthetic pigments of cowpea seedlings in unrefined oil tainted soil compared to the cowpea seedlings in control was noted. Cowpea seedlings raised in unrefined oil tainted soil had lower levels of antioxidants relative to the control. Conversely, lipid peroxidation was elevated in seedlings raised in unrefined oil tainted soil. The activities of glutathione s-transferase, sulphite oxidase, xanthine oxidase and aldehyde oxidase significantly reduced in cowpea seedlings raised in soil tainted with unrefined oil without addition of OPL as compared to those of the control and all OPL protocols. The significant improvement in photosynthetic pigments, beta carotene as well as the antioxidant profile of cowpea seedlings in untainted soil treated with OPL when compared with those in control group, alongside the substantial ameliorative effect on chlorophyll, beta carotene and the antioxidant profile of cowpea seedlings in OPL amended soil, suggests that OPL addition to unrefined petroleum oil tainted soil reduced petroleum toxicity on cowpea seedlings.

Effect of Maize Husk Treatment of Crude Oil Contaminated Soil on Morphological and Biochemical Indices of Cowpea Seedlings

“…These observations are in line with earlier observations by several authors (Achuba 2006;Sivaraj et. al., 2014;Achuba and Iserhienrhien, 2018;Achuba, 2019). The increase in morphological indices of cowpea seedlings growing in maize husk treated crude oil polluted soil showed a potential ability of maize husk to remediate toxic effects of crude oil as reported by Abiodun et al (2016).…”

“…The increase in morphological indices of cowpea seedlings growing in maize husk treated crude oil polluted soil showed a potential ability of maize husk to remediate toxic effects of crude oil as reported by Abiodun et al (2016). In fact, the ability of cellulosicrich materials to enhance soil enzyme activities and improve the performance of plants in soils polluted by hydrocarbon has been documented earlier Achuba, 2019). This observation also gives credence to the postulation that organic materials reduce the impact of crude oil on plants (Ekpo and Nya, 2012;Sivaraj et al 2014;Achuba and Ja-anni, 2018;Achuba and Ohwofasa, 2019).…”

“…The sources of soil sample and cowpea seeds used were previously described (Achuba and Okoh, 2015;Achuba, 2018b). The physicochemical features of soil sample were published earlier (Achuba, 2019). Analytical grade reagents were used for determination of each parameter.…”

“…Contamination with hydrocarbons has been one of the major environmental challenges associated with crude oil production Achuba, 2019). Crude oil is rich in various classes of hydrocarbons and their interaction with the soil result in the restriction of oxygen and water flow due to petroleum-mediated altered soil permeability (Otunyo, 2010;Nazir, 2011;Ewetola, 2013;Akinwumi et al, 2014;Jesna and Hari, 2015;Ayininuola and Kwashima, 2015) The restriction of oxygen availability to biological system in soil perturbs both aerobic and anaerobic respirations in exposed organism.…”

“…The altered respiration stimulates oxidative damage which predisposes exposed plants to an array of metabolic and pathological maladies (Achuba 2015;Achuba and Jaanni, 2018;Achuba and Oshiokpu, 2019).Biological approaches towards bioremediation with low economic cost and eco-friendly natural products, have led researchers to employ organic wastes as an alternative to high cost inorganic fertilizers. In recent times, an array of agricultural wastes has been tried either as organic manure or soil reconditioning material against crude oil toxicity in exposed plants (Achuba and Erhijovwo, 2017;Achuba and Ja-anni, 2018;Achuba and Ohwofasa, 2019;Achuba, 2019). Organic wastes (animals and plant) are host to large groups of microbes during the process of decomposition.…”