Improvement of soil quality through biochar in rice under wastewater irrigated soil: Effects on heavy metals reduction

Abstract

Purpose: Rice, a global staple, can accumulate high levels of heavy metals especially Chromium (Cr) when grown in a soil irrigated with tannery effluent over time, potentially reaching toxic levels for human consumption. Biochar offers a cost-effective solution by binding these heavy metals in soil, reducing their bioavailability and mitigating health risks. The present study offers a two-way solution of reducing weed load of agricultural fields through parthenium biochar preparation and its application in Cr contaminated soil with aim of its lower accumulation in the edible part of the crop. Method: The investigation consists of ten treatments in completely randomized design with three replications using simple and concentrated H<inf>3</inf>PO<inf>4</inf> and 1 M FeCl<inf>3</inf> modified biochar at graded dose and one biochar untreated control. All treatments receive a recommended dose of NPK fertilizers. Results: Our study shows that biochar produced from parthenium can reduce uptake of heavy metals in the plant body. Moreover, modification of biochar by H<inf>3</inf>PO<inf>4</inf> and FeCl<inf>3</inf> hastened the metal fixation and further reduced the metals accumulation in different parts of plant body depicted by lowering translocation factor (TF) along with translocation coefficient (TC). Conclusion: Overall, application of biochar is proven to reduce the metals accumulation in rice plant parts and grains rendering it a good amendment. © 2025 The Author(s).