Starch and triglycerides in the root of maize (Zea mays) and cowpea (Vigna unguiculata) grown in crude oil polluted soil treated with ash from palm bunch

Abstract

The ash from burnt oil palm fruit bunch has been commercially known and used as natural fertilizer for neutralizing peaty and acidic soils. This study was conducted to evaluate the use of ash from palm bunch (APB) as a source of biological fertilizer and soil amendment to neutralize the acidic pH created by crude oil contamination on the starch and triglycerides contents in the roots of maize and cowpea seedlings. The physicochemical characteristics of the APB reveals it may be a good source of nutrients to improve soils to be used for agriculture. The results shows that application of APB significantly (P<0.05) increased soil pH, soil sodium, potassium, calcium and magnesium. The plant height were significantly increased and comparable to that of the control. This shows that APB contains nutrients important for plant growth and may contribute to bioremediation. There were significant changes in the starch and triglyceride contents of the maize and cowpea seedlings in contaminated soils when compared with control. The study reveals alterations comparable to control with the application of APB, however, the degree of response of the two plants to APB differed. The study suggests that APB could be used as fertiliser to increase the pH and the nutrient contents of acidic soils and thus improve the soil quality. Further studies are needed to elucidate the mechanism of alteration of starch and triglyceride contents in the plant species.