<p>Iron (Fe²⁺) toxicity is more prevalent in lowland rice ecosystems, where it negatively affecting rice growth and causing substantial yield losses. This yield loss causing Fe²⁺ toxicity has to be addressed using cost-effective farm-based materials and agronomic practices.&#xa0;This study therefore evaluated rice husk (RHB) and bamboo biochar (BB) as adsorbent for Fe²⁺ removal from aqueous solution via adsorption experiment. Subsequently, their efficacy in alleviating Fe²⁺ toxicity in rice cultivated under two contrasting moisture regimes (continuously waterlogged (CW-MR) and continuously saturated moisture regime (CS-MR)) was evaluated through pot experiment.&#xa0;The maximum adsorption capacity of RHB and BB was 2.23 and 1.36 mg g^− 1, respectively. The Fe²⁺ adsorption on RHB and BB was well fitted by Langmuir and Freundlich isotherm (R² &gt; 0.96), respectively. In pot experiment, application of 5% biochar significantly increased soil pH, and available phosphorus (P) and silicon (Si), regardless of moisture regime, compared to control. Both biochar under CS-MR significantly reduced the phytoavailable Fe²⁺ in soil. Relative to control, biochar treatments significantly increased rice biomass and growth by lowering Fe²⁺ availability and tissue accumulation, with better growth under CW-MR likely due to beneficial effect of Si and greater water availability. Application of RHB under CW-MR enhanced iron plaque formation on rice roots. Biochar application under CS-MR improved chlorophyll content and photosynthetic parameters of rice.&#xa0;Finding from this study suggest that application of RHB at the rate of 5% under CW-MR could be a potential option to alleviate Fe²⁺ toxicity in lowland rice ecosystems.</p>