The recycling of waste wheat straw into biochar for soil improvement is a promising, sustainable strategy to enhancing nutrient-poor soils. Biochar application to soil has been shown to enhances the activity of key enzymes involved in nutrient cycling, such as invertase (INV), urease (URE), and alkaline phosphatase (ALP), which play roles in carbon (C), nitrogen (N), and phosphorus (P) cycling, as well as catalase (CAT), an enzyme with redox properties. However, the kinetic behavior of these enzymes remains largely unexplored. A 36-week laboratory study was conducted to evaluate the effects of biochar on enzyme kinetics in grey desert and aeolian soils including Michaelis-Menten constant (K