Biostimulation of Organomineral Amended Asa River Sediment in Ilorin, Kwara State, Nigeria

Globalization and increase in anthropogenic activities has led to heavy metal pollution of most agricultural soils and ecosystem due to large and indiscriminate discharge of toxic effluent into water ways and agricultural lands. An experiment was conducted at the University of Ilorin Dam site to evaluate the effectiveness of three organic wastes singly and in combination with NPK as bio-stimulating agent to remediate Asa River Sediment. Randomized Complete Block design in split plot arrangement was adopted using three local amendments: abattoir effluent (AE), poultry droppings (PD) and rice husk (RH) at two levels. Soil samples collected before and after planting were analysed for heavy metals (Mn, Fe, Pb, Zn, Cu, Co, Ni, Cr, Cd) using Atomic Adsorption Spectrophotometer. The result shows that application of AE was more effective in bioremediating heavy metals in Asa River Sediment with a reduction of 99.07% in soil, 99.82% in maize tissue, and 99.97% in maize grain, as compared to rice husk; 99.04% in soil, 99.81% in maize tissue and 99.96% in maize grain and poultry dropping 98.72% in soil, 99.79% in maize tissue and 99.96% in maize grain respectively. Heavy metals in the remediated soil varied in the order Mn>Fe>Pb>Zn>Cu>Co>Ni>Cr>Cd in soil, plant tissue and grain and were also observed to be below the maximum permissible limit as set by FAO/WHO. The findings of the research shows organic wastes were effective in remediating heavy metal in Asa sediments with abattoir effluent observed to be more effective than poultry droppings and rice husk.