Mitigating exogenous cobalt-induced stress in maize plants with biochar and arbuscular mycorrhizal fungi (Rhizophagous intraradices)

Abstract

The effects of cobalt contamination on maize plant growth and the potential benefits of arbuscular mycorrhizal fungi (AMF) and biochar (B) as low-cost amendments for improving plant growth in metal-polluted soils were investigated in a pot experiment. The experiment evaluated the impact of Rhizophagous intraradices and biochar on maize plants grown under different cobalt concentrations (0, 60, and 120 ppm). A wide range of physiological parameters, including plant height, number of leaves, root and shoot fresh and dry weight, relative water content, electrolyte leakage, chlorophyll and carotenoid content, oxidative stress, cobalt distribution, and nutrient content, were analyzed. The results revealed that cobalt contamination had a negative impact on plant growth, reducing chlorophyll and carotenoid content, increasing oxidative stress, and elevating cobalt accumulation in the shoot while also decreasing nutrient content. However, Rhizophagous intraradices inoculation and biochar application were shown to be effective in reducing cobalt uptake in aerial parts, improving nutrient content, and reducing oxidative stress. This study highlights the potential of AMF and biochar as cost-effective amendments for improving maize growth and mitigating cobalt toxicity in contaminated soils.