Joint agricultural input use and food security: evidence from Tanzania

The joint use of hybrid seeds and inorganic fertilizer, at appropriate levels, is necessary to boost cereal productivity by supplementing soil nutrients in Sub-Saharan Africa (SSA). While these two inputs are ‘paired’ together for integrated soil nutrient management, empirical studies often focus on the use of one of these inputs as a dichotomous choice. This study models the joint use of hybrid seeds and inorganic fertilizer and its impact on different dimensions of food security. The analysis is based on a sample of 1,653 unique maize growing households (3,306 observations) over 4 rounds of the Living Standards Measurements Study – Integrated Surveys of Agriculture (LSMS-ISA) from Tanzania, spanning 10 years between 2010/11 to 2020/21. The Multinomial Endogenous Switching Regression with Correlated Random Effects (MESR + CRE) models self-selection into four potential regimes of input use. The results show that the Average Treatment on the Treated (ATT) of joint inputs use increased maize productivity by 17–39 % and improved food utilization with more diverse diets, by 1.9 food groups in some cases. Further, Average Treatment on the Untreated (ATU) estimates show that farms that do not use both inputs could improve their food security. However, the improvements are restricted by low profitability or even losses under joint input use. Sub-sample analysis in this study shows that the treatment effects are quite heterogenous. Households with more exposure to heat and moisture stress and limited access to services face lower profitability on adoption, limiting the impact on food security outcomes. The findings from this study suggest more targeted approaches to incentivize joint input use and diversification of strategies since agricultural input-based interventions may have limited impacts for households exposed to adverse weather and experiencing severe food insecurity.