Improved Seeds and Rice Productivity in Tanzania: Policy Insights from National Sample Census Data

Improving rice productivity remains a central pillar of Tanzania’s national strategy to achieve food security and rural development. While improved seed technologies have long been promoted as a pathway to higher yields and poverty reduction, there is limited empirical evidence on their actual performance at scale. This study utilizes nationally representative data from the 2019/20 National Sample Census of Agriculture (NSCA), complemented by the 2007/08 NSCA, to assess the impact of improved seed use on rice productivity in Tanzania, disaggregated by agroecological zones (AEZs) and seed types (improved vs. local). A stochastic simulation model was employed to evaluate the likelihood of rice farms meeting or exceeding productivity thresholds under varying conditions while controlling for other production factors. Two threshold-based scenarios were analyzed: (i) the probability of yield exceeding the standard national benchmark of 3.0 t/ha and (ii) the probability of surpassing the global high-yield benchmark of 4.5 t/ha. The results reveal that rice farmers using improved seeds consistently outperform those using local seeds in both yield level and probability of surpassing key productivity thresholds. Nationally, improved seed users had a 12% probability of exceeding 4.5 t/ha, compared to 6% among local seed users. Farms in Mainland Tanzania had a 15% rate, versus 6% for local seed users. Farms in Zanzibar had a 7% higher yield compared to only 2% for non-users. These benefits were more pronounced in high-potential AEZs such as the Southern Highlands and Eastern Zones, highlighting the role of agroecological targeting in input efficacy. Moreover, improved seed adoption reduced the risk of sub-optimal yields (< 1.5 t/ha), contributing to production stability and resilience. This study provides new insights for policymakers and development actors on the actual yield gap between improved seed users and non-users in rice production systems. The findings provide a critical baseline for informing seed sector reform, targeted subsidy programs, and planning for agroecological inputs. The research further contributes to advancing several Sustainable Development Goals (SDGs), particularly SDG 2 (Zero Hunger), SDG 1 (No Poverty), and SDG 12 (Responsible Consumption and Production). To optimize the benefits of improved seeds, the study recommends integrated approaches that combine seed adoption with access to complementary inputs, extension services, and market linkages.