In recent years utilization of in-organic fertilizers in Tanzania has more than doubled due to many factors including government subsidies through the National Input Voucher Scheme (NAIVS). However the increase is more pronounced on use of Urea, Di-Ammonium Phosphate (DAP) and Calcium Ammonium Nitrate (CAN) which accounts for more that 60% while Potash fertilizer through NPK and other compound fertilizers account for the rest. Using the "Law of Minimum", this paper analyse and model the missing opportunity for maximizing crop productivity and associated economic losses due dismal levels of Potash fertilizer utilization the country. The paper suggest for a strategic fertilizer blending programmes to increase use of potash utilization to avoid the trap evidenced by the Law of Minimum.