Impacts of Fertilizers Coupled with Improved Seeds on Rice Profitability in Tanzania: Evidence from the National Sample Census of Agriculture 2019/20

Ibrahim Kadigi Lwaho Kadigi^1,2*Stefan Sieber^3*

• ¹Sokoine University of Agriculture, Morogoro, Tanzania
• ²Mbeya University of Science and Technology, Mbeya, Tanzania
• ³Department of Agricultural Economics, Leibniz Center for Agricultural Landscape Research (ZALF), Müncheberg, Germany

Climate change increasingly threatens food security in Tanzania, where smallholder rice farmers rely on rain-fed agriculture and have limited adaptive capacity. This study evaluates the effectiveness of improved seeds and fertilizers as strategies to enhance farm profitability and resilience. We used data from Tanzania's 2019/20 National Sample Census of Agriculture (NSCA), covering 6,025 rice farms. A Risk Simulation Model (RSM) was employed to analyze income distributions under variable yield and price conditions. Farms were categorized by seed type (local vs. improved) and fertilizer use (organic, inorganic, or none). Results reveal that combining improved seeds with inorganic fertilizers significantly boosts profitability. In the Southern Highlands Zone (SHZ), 20% of farms exceeded the upper-income threshold of TZS 4.0 million/ha. In contrast, farms using local seeds without fertilizers faced severe financial risks, with 78% earning below TZS 2.0 million/ha nationally. Organic fertilizers offered modest benefits. For example, in Zanzibar, they reduced the likelihood of low-income households by 14%, though they failed to match the transformative impact of inorganic inputs.Regional disparities were pronounced. SHZ's fertile soils amplified the efficacy of inputs.Meanwhile, the Eastern Zones (EZ) and Zanzibar faced multiple constraints, including saline soils, fragmented plots, and institutional gaps, which limited the gains from adopting improved practices. Even with the use of inorganic fertilizers, 58% of farms in these areas remained below the national income threshold. These findings underscore the need for spatially targeted interventions. High-potential areas, such as SHZ, could benefit from scaling up subsidized access to improved seeds and inorganic fertilizers, possibly through digital voucher systems.For EZ and Zanzibar, integrated approaches are needed. These include site-specific soil testing, soil improvement programs, and the use of saline-tolerant seed varieties. In addition, strengthening extension services, expanding climate-resilient infrastructure, and improving access to affordable credit are essential. A dual approach, delivering short-term input subsidies while building long-term resilience, will accelerate progress toward SDG 2 (Zero Hunger).Empowering smallholders through inclusive and evidence-based policies can promote sustainable profitability and enhance national food security.