Dust-induced metal toxicity alleviated by the combined effect of organic and inorganic amendments on soil and plant

Abstract

ABSTRACT Metals contaminated dust alongside the roads caused toxicity in agriculture soils and crops which is an extensive problem. Therefore, a pot experiment was conducted to evaluate the different organic and inorganic amendments to alleviate dust-induced metal toxicity in soil and plants. For this purpose, dust was collected for 12 weeks (39 g per week) from 10-m distance along the M4 motorway. The dust rate of 39 g was applied foliarly to plants in pots having treatments namely silicon foliar spray 50% and 100%, biochar, and farm manure 0.5% and 1%, gypsum and rock phosphate 125, 250 and 500 mg kg−1 except for control (no dust). The results revealed that utilizing farm manure at a rate of 1% significantly improved plant growth and physiological parameters. The biochar application at a rate of 1% reduced metal contents in soil, roots and shoots of plants while enhancing antioxidant enzyme efficiency. Furthermore, the foliar application of silicon foliar spray reduced metal toxicity, particularly in plant leaves, by immobilizing metals on their leaf surfaces. Therefore, it is concluded that the use of biochar and farm manure has the potential to reduce metal toxicity in soil and plants while silicon foliar spray was effective on plant leaves.