Biochar as a Soil Amendment for Toxic Elements Reduction and Growth Promotion in Beta vulgaris L. Cultivation Under Wastewater Irrigation

Industrial wastewater (WW) is a common source of toxic elements (TEs) originating from various anthropogenic activities such as improper WW disposal, agricultural runoff, industrial processes, mining, rapid urbanization, and poor sanitation systems, which are major causes of water pollution in low‐ and middle‐income countries. This study was conducted to assess health risks associated with beetroot cultivation under biochar (BC)‐treated WW across three locations of Faisalabad; University of Agriculture, Faisalabad (UAF; Lat 31.4416°, Long 73.0766°), Satyana Farm (SF; Lat 31.3644°, Long 73.1443°), and Uchkera Farm (UF; Lat 31.452°, Long 73.009°). It aimed to evaluate the impact of BC and WW on the growth and development of beetroot grown in different soil types and using diverse WW sources. Data on TEs content revealed maximum uptake in beetroot bulbs under WW treatments, which caused oxidative damage and deterioration in all growth and yield attributes. Bulb fresh and dry weight were reduced by up to 53% and 47%, respectively, under WW irrigation compared with canal water. However, BC amendment played a significant role in TE management by immobilizing them at functional group sites through ion exchange, surface precipitation, microporosity, and surface complexation. In conclusion, BC treatment reduced reactive oxygen species production, restricted TEs uptake, and enhanced antioxidant activities, secondary metabolite production, and chlorophyll pigment content, thereby improving growth and bulb yield of beetroot under WW irrigation. TEs uptake was highest in the second year compared with the first, likely due to hyperaccumulation from continuous WW irrigation. This study highlights potential of wood biochar to improve growth and TEs tolerance in beetroot irrigated with wastewater supporting its broader applicability, real‐world effectiveness, and role in promoting safe water reuse.