Amending soils with sewage sludge biochar is a promising waste management strategy and value-added approach to reuse the waste while minimizing environmental contamination risks. Soil pot experiment was conducted to examine the effect of a 300°C sludge-biochar in soil health and crop productivity using a strongly acidic soil. Three treatments of the soil pots were included: 1% biochar– (10 g kg-1 biochar/soil ratio), 2% biochar– (20 g kg-1 biochar/soil ratio), and control (soil without biochar). Winter wheat (Triticum aestivum L.), spinach (Spinacia oleracea), and mung bean (Vigna radiata) were grown sequentially in the soil pots over 9 months under greenhouse and field conditions. Plant biomass and soil health parameters were assessed. Soils amended with 2% biochar demonstrated higher biomass in winter wheat, spinach, and mung bean compared to unamended control treatments. The effect of sludge biochar was not observed in soil bulk density; however, soil aggregates stability was higher in soils amended with 2% biochar (24.17%) compared to control (21.38%). Soil acidity was corrected in soils amended with 2% biochar (pH value 6.5) compared to control (5.8), electric conductivity (EC) was higher in 1% biochar (0.25 dS m-1) compared to control (0.20 dS m-1). Respiration rate was higher in 1% biochar (0.52 mg CO2 g-1 dry soil) compared to control (0.43 mg CO2 g-1), and total organic carbon (TOC) was lower in soils amended with biochar compared to control. Sewage sludge derived biochar improved crop production and soil health in strongly acidic soils and should be adopted in commercial agriculture.