This study develops an Economic Order Quantity (EOQ) model for ameliorating inventory items subject to a time-dependent quadratic demand rate and partial backlogging. Amelioration, where the quality or quantity of stored items increases over time as observed in the items like poultry, fish, fruit and piggery that are incorporated into the model alongside demand patterns that accelerate quadratically. The model also allows for partial shortages, with backlogging rates dependent on customer waiting time. Using calculus-based methods, a cost function was formulated to determine the optimal cycle length that minimizes total variable costs. Numerical examples validate the model, and sensitivity analysis identifies the key parameters that influence optimal cycle length, total cost, and order quantity. The result shows that parameters like amelioration rate, cost components, and demand coefficients significantly influence the inventory decisions. This model offers a practical framework for inventory management in industries dealing with improving items and non-linear customer demand behavior.