EFFECT OF BIOCHAR APPLICATION ON HEAVY METAL ACCUMULATION IN RED AMARANTH (Amaranthus spp.) GROWN IN CONTAMINATED SOIL

Abstract

A pot experiment was conducted at the net house of the research farm of Sher-eBangla

Agricultural University, Dhaka-1207 during the period from JanuaryJune 2018. The experiment was conducted to observe the effect of biochar (BC)

on cadmium

(Cd) accumulation in red amaranth (Amaranthus spp.) and on soil health. In this experiment, the treatment consisted of four doses of BC viz. BC 0 = no BC, BC 1 =1% BC of soil wt., BC 2 = 2% BC of soil wt., BC 4 = 4% BC of soil wt. and Cd 0 = no Cd, Cd 5 = 5 ppm Cd, Cd 15 = 15 ppm Cd. The experiment was laid out in Complete Randomize Design (CRD) with five replications. The collected data were statistically analyzed for evaluation of the treatment effects. Results showed that significant variations were found among the treatments for the observed parameters such as Cd in stem, leaf and root, total and available Cd in bulk and rhizosphere soils, soil pH, bulk density and porosity. The lowest Cd accumulation in plant stem, plant leaf and plant root was found in the treatments with 4% BC of soil wt. addition. Higher amount of total Cd in bulk and rhizosphere soil was observed in the treatments of higher amount of BC .However, lower amount of bio-available Cd was found in soils with higher amount of BC indicating that stabilization of Cd is promoted by BC. Biochar application also reduced the bulk density and increased porosity and pH indicating improved soil health for better crop production in an acid soil. It was observed from this study that red amaranth accumulated significant amount of Cd even at low concentration (5ppm) which is alarming. As BC reduced the Cd accumulation significantly it can be concluded that metal stabilizer like BC may be used as soil amendment in reducing the heavy metal uptake by leafy vegetables grown in contaminated soil