Modeling the profitability potential of inorganic fertilizer use for maize production in Tanzania under seasonal price volatility

Maize remains a cornerstone crop in Tanzania, underpinning household food security, rural incomes, and national economic stability. Despite its importance, the profitability of maize production under different fertilizer regimes remains poorly understood, especially for smallholder farmers operating across diverse agroecological environments. This study assesses the influence of inorganic and organic fertilizers on maize profitability across Tanzania’s major agroecological zones using nationally representative data from the 2019/20 National Sample Census of Agriculture (NSCA). A non-parametric Monte Carlo simulation model was applied to estimate net farm income under three fertilizer scenarios: no fertilizer, organic fertilizer, and inorganic fertilizer, while accounting for production and market uncertainties. Findings show that both organic and inorganic fertilizers increase the likelihood of achieving profitable outcomes, particularly when maize is sold during the peak marketing season (October–March), when prices are highest. However, profitability varies substantially across agroecological zones due to differences in rainfall patterns, soil quality, market access, and seasonal price fluctuations. Although inorganic fertilizers contribute to higher yields, their elevated input costs often reduce net farm returns, making organic fertilizers comparatively more profitable in several regions, including the Southern, Northern, Lake, and Central zones. Notably, over 83% of farmers across all fertilizer categories still fall below profitability levels when they lack timely access to high-price markets, indicating that fertilizer use alone is insufficient to ensure economic viability. The study concludes that while fertilizers, especially inorganic inputs, play an essential role in boosting productivity, sustainable maize intensification in Tanzania will require complementary interventions. These include improved postharvest storage to enable delayed sales, strengthened input delivery systems, and strategies that enhance farmers’ ability to time seasonal markets. Such measures are essential for converting productivity gains into meaningful and sustained profits for smallholder farmers.