In a pot experiment followed a randomized completely block design with three replications, the effect of banana pseudostem biochar on potassium quantity/intensity (Q/I) parameters, soil chemical properties, and barely growth and nutritional statue in loamy sand soil was investigated. The biochar was applied to soil at three levels included 0% (control treatment), 0.5% (B1), 1% (B2), and B3 (2%). Barely grains were planted, after harvest each soil treatment was analyzed for potassium forms, some chemical properties (pH, salinity, organic matter content, total nitrogen, available phosphorus) and potassium Q/I parameters. The plants were analyzed for nutrients (nitrogen, phosphorus, potassium) content and nutrients uptake was calculated. The results showed significant improvement in soil organic matter content, total nitrogen, and soil available phosphorus. The potassium forms (water soluble K, exchangeable K, HNO3-extractable K, and non-exchangeable K) increased significantly with application of biochar compared to control soil. Also, significant increases resulted in the soil potential buffering capacity of K (PBCk), potassium activity ratio in soil at equilibrium (ARek), and the labile K pool (-∆Ko) with addition of biochar to the studied soil. Fresh and dry weights, NPK contents and uptakes by barely plants enhanced significantly with biochar application. Therefore, the biochar produced from banana tree waste is beneficial tool for long-term carbon sequestration, enhancing soil fertility and plant health. The banana pseudostem biochar application can be an effective way for enhancing soil potassium availability, replenishment and storage, which could lessen the demand for synthetic chemical K fertilizers and promote sustainable agriculture techniques.