Blessing Funmbi Sasanya
Several health and environmental hazards had been associated with the use of synthetic fertilizers. It is, therefore, appropriate to look into possible alternatives which can assure safety. Hence this study aims to investigate and compare the effect of bioslurry on the heavy metals and anion contents of vegetables planted on bioslurries amended soils, inorganic fertilizers amended soils and soil with no amendments. Two vegetables Amaranthus hybridus (A) and Corchorus olitorius (C) as well as five treatments; piggery bio-slurry (V), poultry bio-slurry (W), piggery+poultry bio-slurry (X), inorganic fertilizer (Y) and the control (Z) were employed in the experiments. Nine samples of each vegetable type were harvested from each of the treatments for heavy metals and anion contents analysis from the plant leaves based on IITA (2001) standards. The highest Ca2+, Mg2+, K+, Mn2+, Fe2+, Cu2+, Zn2+, NO3-, and PO43- contents of the plant type A are 551, 363, 1820, 4.11, 49.50, 0.92, 4.62, 28.40 and 16.30 mg/kg for treatments X, X, V, W, W, W, X, X and V respectively. The highest Ca2+, Mg2+, K+, Mn2+, Fe2+, Cu2+, Zn2+, Pb2+, NO3-, and PO43- contents for the plant type C is 233, 162, 1170, 5.20, 39.1, 2.53, 4.00, 15.30 and 7.18 mg/kg for the treatments X, X, Z, Z, Z, Z, Z, W and W respectively. The heavy metal and anion contents of both plant types are below recommended adequate daily intake (ADI) for all the treatments with the exception of Fe2+ in the plant type A for the treatment W and Pb2+ in the plant type C for the treatments Y and Z. Generally, the vegetables planted with bio-slurry are safe for consumption.