Researchers studied how different soil characteristics affect the availability of potassium in smectitic soils. They analyzed soil texture, organic carbon, clay mineralogy, potassium fractions, and potassium sorption. Results showed that Vertisols had the highest potassium content, followed by Alfisols and Inceptisols. The percentage of different potassium fractions varied among soil types. Soil clay, organic carbon, and cation exchange capacity significantly influenced potassium availability. Smectite, a type of clay mineral, played a key role in controlling potassium buffering capacity. To improve potassium fertilizer efficiency, plants that release organic acids from their roots could be developed for smectitic soils. Consideration of sodium, ammonium, and iron cations is also important for potassium management in these soils.