---

Author(s): Jumanne Ally Setonga.

Volume/Issue: Volume 9, Issue 2 (2026)

Page No: 21-47

Journal: African Journal of Agriculture and Food Science (AJAFS)

---

Abstract:

Maize is a staple crop in the region, and its productivity plays a vital role in ensuring food security and improving the livelihoods of smallholder farmers. Despite the potential for high yields, smallholder farmers face challenges in optimizing production due to factors such as limited access to modern farming technologies, insufficient institutional support, and high input costs. This study explores the effect of technological factors, institutional factors and production costs on maize productivity among smallholder farmers in Songea District, Tanzania. The study uses a cross-sectional design collected data from 397 smallholder maize farmers. To address potential endogeneity arising from key variables such as credit access, land size, and fertilizer use, the analysis employs an instrumental variable Two-Stage Least Squares (IV-2SLS) estimation. The IV regression results reveal that both technological and institutional factors play a significant role in improving maize productivity. In the second-stage estimates, land size (p < 0.05) and credit access (p < 0.01) significantly increase productivity, indicating that scale effects and financial access enable farmers to allocate inputs more efficiently. Technological variables including improved seed adoption (p < 0.01), inorganic fertilizer use (p < 0.01), integrated pest management (p < 0.01), and tractor use (p < 0.01) also have strong positive effects on maize output per worker. Institutional factors further contribute to productivity gains. Market access (p < 0.01) and training attendance (p < 0.01) significantly improve output; suggesting that improved information flows and market integration enhance production efficiency. Household labor (p < 0.01), household size (p < 0.01), income (p < 0.01), and favorable rainfall conditions (p < 0.01) also positively influence maize productivity. In contrast, higher fertilizer costs (p < 0.01), pesticide costs (p < 0.01), and seed costs (p < 0.01) significantly reduce productivity, indicating potential inefficiencies in input expenditure and diminishing marginal returns to cost increases. Elasticity estimates from the Cobb–Douglas IV model show that fertilizer use (0.499), land size (0.853), and labor (0.042) positively contribute to maize output. Hypothesis testing confirms diminishing marginal productivity of fertilizer and labor, while land size exhibits constant marginal productivity. The combined elasticity of core inputs suggests that maize production operates under constant returns to scale. Thus, strengthening access to agricultural inputs, credit services, extension programs, and market infrastructure can significantly improve maize productivity and contribute to food security and rural income growth in Tanzania.

Keywords:

Technological factors, Institutional Factors, Inputs costs, Maize Productivity, Endogeneity, Instrumental Variable Regression, Cobb–Douglas.

No. of Downloads: 0