Influence of Aspergillus Niger, Penicillium and Trichoderma fungi on the growth of Amaranthus Caudatusin heavy metals amended soil fromTsamawa, Kano State

Abstract

Soil sample from Tsamawa irrigation site was amended with 10 mg/L of Cadmium (Cd), Chromium (Cr), Manganese (Mn), Nickel (Ni), Zinc (Zn) and Lead (Pb) separately in polythene bags. 4.0 x 10 ⁶ CFU/L Aspergillus niger (An), Trichoderma (Tr) and Penicillium (Pn) fungal species were injected into the soil after planting Amaranthus caudatus seeds. Water was being added to the set-up after every 3 days interval for a period of 6 weeks during which measurements were taken from the 3^rd to 6^th week. The plants were uprooted and separated into shoot and root then prepared for AAS analysis to determine the effect of the fungi on metal uptake by the plants and also to determine Statistically the variations between the growth of the plants. The highest plant height (18.49 cm) was recorded in Ni amended soil with Tr, while An and Pn had slight influence on the plant growth. Tr generally promoted the best plant growth in Cd, and Ni amended soils, while An andPn showed mixed effects, sometimes reducing plant growth. For the metal uptake, by the fungi in roots, An promoted high Cr (5.05 mg/kg), Pb (1.75 mg/kg) and Ni(4.15 mg/kg) accumulation, Pn accumulated Cd (0.78 mg//kg) and Mn (1.42 mg/kg while, Tr accumulated Zn (4.4 mg//kg).These findings proved that the selected fungi can be used in remediating contaminated soil as they are found to be good accumulators of the heavy metals hence, reducing their availability to the plants as well as promoting the plant growth.