GROWTH AND ARSENIC ACCUMULATION PATTERN OF ARUM UNDER DIFFERENT ORGANIC AMENDMENT

Abstract

A pot experiment was conducted at the rooftop of Academic Building 1, Hajee Mohammad Danesh Science and Technology University (HSTU) from December 2022 to June 2023 to assess the growth performance of arum and to evaluate the accumulation behavior of Arsenic (As) in response to varying concentrations of As and rice husk biochar. The experiment was conducted in pots with a Completely Randomized Design (CRD) with three replications. There were seven distinct treatment combinations, each involving different levels of As an organic amendments (OAs): No amendments (Control), Cow dung (CD) at 2.5% kg-1 soil, Vermicompost (VC) at 2.5% kg-1 soil, Wood biochar (WB) at 2.5% kg-1 soil, Rice husk biochar (RHB) at 2.5% kg-1 soil, Modified biochar (MB) at 2.5% kg-1 soil, Combination of VC and MB [(1.25% + 1.25%) kg-1 soil]. The data were collected on plant height (cm), fresh shoot biomass pot-1 (g), fresh root biomass pot-1 (g), individual root length plant-1 (cm), SPAD value, ascorbate peroxidase (µM/g FW), catalase (µM/g FW), peroxidase (µM/g FW), shootAs (mg kg-1 DW), root As (mg kg-1 DW), postharvest soil As (mg kg-1 DW), translocation factor (TF), bioaccumulation factor (BAF). The results showed that plant height at 15 and 35 days after transplanting (DAT) varied significantly with treatment, with WB and VC showing the tallest plants. SPAD meter readings indicated higher chlorophyll content in OA-treated plants compared to controls (p < 0.01). Antioxidant enzyme activities (CAT, POD, APX) were highest in control and lowest in T7 treatment (p < 0.01), indicating reduced oxidative stress response with OAs. OAs significantly increased fresh shoot and biomass per plant (p < 0.01), with T4 and T6 treatments yielding the highest biomass. Arsenic concentrations in plant tissues were lowest with MB treatment, showing a strong negative correlation with soil As (r = –0.92; p < 0.01). Phytoextraction analysis revealed the highest As removal in control soils, but lower translocation factor (TF) and bioaccumulation factor (BAF) with OAs. These results highlight the potential of biochar and other OAs to enhance plant growth, reduce As uptake, and improve antioxidant defenses in arsenic-contaminated soils, offering viable strategies for managing As toxicity in agriculture.