Biochar Effects on Vegetative Characteristics and Chemical Composition of Panicum miliaceum Grown in a Pb-Contaminated Rangeland Soil

Abstract

ABSTRACT Use of biochars can be effective in increasing the uptake of plant nutrients and stabilizing heavy elements in the soil. The aim of this study was to investigate the effect of biochar application and lead (Pb) levels on some vegetative characteristics and concentrations of micro and macronutrients of Panicum miliaceum grown in rangeland soil under greenhouse conditions. A factorial pot experiment was conducted in a completely randomized design with four replications. The first factor includes biochars (no application of biochar (C), wheat biochar (1.5% w/w) (GB1), wheat biochar (3% w/w) (GB2), corn biochar (1.5% w/w) (ZB1), corn biochar (3% w/w) (ZB2), cotton biochar (1.5% w/w) (PB1) and cotton biochar (3% w/w) (PB2)) and the second factor consisted of Pb levels (0 (Pb0), 150 (Pb150) and 300 (Pb300) mg Pb kg−1 soil). With enhancing the Pb levels from Pb0 to Pb300, the concentration of plant iron (10.46%), manganese (5%), and phosphorus (4.78%) were significantly reduced. While, all the biochars (GB, ZB, and PB) at the level of 3% (w/w) caused a significant increase in the concentration of Fe, Mn, P, and K of plant shoot and decreased the Pb concentration of plant shoot and root. The GB2 treatment was more effective than other biochars in improving the vegetative characteristics, increasing nutrient concentration of the shoot, and reducing the Pb content in the shoot and root. It can be concluded that the use of biochar can be of great help in implementing breeding projects for Pb contaminated pastures.