Two field experiments investigated the effects of wood biochar (WB), cow dung biochar (CDB), and green manure (GM) on tiger nut (*Cyperus esculentus*) growth and soil properties. Treatments included CDB, WB, GM, CDB+GM, WB+GM, and a control. All treatments (sole or combined) improved soil moisture, organic carbon, nutrients, and microbial populations compared to the control. CDB and CDB+GM showed the best results for growth and yield, attributed to CDB's higher nutrient content and cation exchange capacity. GM alone also improved growth, while combining biochar with GM led to synergistic effects on yield, likely due to nutrient retention from GM by the biochar. The study highlights the benefit of combining biochar with a fast-releasing nutrient source for optimal soil fertility and tiger nut yield.
