Comparative study of different rates of composts made from mexican sunflower (Tithonia diversifolia) and cassava peels on maize growth on lead contaminated soil.

Abstract

Attempts made by several researchers to reduce the effects of soil contamination and enhance crop growth are either expensive or ecologically-unacceptable. Greenhouse experiment was conducted to test for the effects of different rates of Mexican Sunflower and Cassava peels composts on remediation of lead contaminated soil and growth of maize planted on it. Application rates of 0 t ha-1 (R1), 10 t ha-1 (R2), 20 t ha-1 (R3), 30 t ha-1 (R4) and 40 t ha-1 (R5) were used and arranged in a Completely Randomized Design. It was observed that compost application enhanced the growth and yield of maize on this soil compared to control. Higher application rates (30 t/ha and 40 t/ha) of both composts significantly increased the plant height, number of leaves, leaf area and dry matter yield of maize planted on the contaminated soils. An increase of up to 95% in maize biomass was achieved with higher rate of compost application. In terms of heavy metal concentration in the maize tissue, application of compost reduced the Pb concentration in the plant tissue compared to control. Maize growth can be improved on contaminated site using compost prepared from Mexican Sunflower and applied at the rate of 30 and 40 t ha-1.