Despite government subsidies and the potential benefits to yield and income, fertilizer use in most of Africa remains low. Determining the barriers to its use and the factors influencing its profitability is critical in increasing its popularity. This study uses longitudinal farm data in a generalized asymmetrical production model in order to approximate maize yields in response to household features, traditional production inputs, and government programs in Zambia. The analysis determined that both input and non-input factors, such as market conditions, application rate, fertilizer availability, animal use, and even death of a family member, played roles in determining yield response and overall profitability of fertilizer use on maize. This research illustrates the importance of considering household heterogeneity in regards to fertilizer use and yield response in both productions models and, perhaps more importantly, in government programming and planning.