Irrigation mediated pathways for improving wheat productivity in water limited smallholder systems of Eritrea

Abstract

Abstract Wheat productivity among smallholders in semi-arid sub-Saharan Africa remains low and highly variable, with yields often below attainable levels. While previous studies have identified numerous determinants of yield, most treat irrigation as an exogenous input, providing limited insight into how household, institutional, and farm-management factors influence productivity through supplementary irrigation. This study applied a mediation framework to examine whether supplementary irrigation mediates the relationship between these factors and wheat productivity among 451 smallholder households in the Eritrean highlands. Irrigation adoption was modelled using a generalized linear model with a logit link, while wheat yield was analysed using ordinary least squares regression. Indirect effects were estimated using bias-corrected bootstrap confidence intervals based on 5000 resamples. Average wheat yield was 1.83 t ha⁻¹, and only 23% of households practiced supplementary irrigation. Supplementary irrigation was positively associated with wheat yield, while certified seed use, gender and labour input, nitrogen application showed significant direct associations with productivity. The effects of extension services, landholding size, crop rotation, credit and farmer’s age on wheat yield operated entirely through supplementary irrigation. These findings identify supplementary irrigation as important pathway linking institutional access and farm resources with wheat productivity. Given fragmented landholdings and moisture-limited production conditions, policies aimed at narrowing yield gaps should prioritize context-appropriate, decentralized supplementary irrigation. These investments should be supported by improved access to irrigation finance and extension services that integrate water and nutrient management, thereby contributing to climate-resilient wheat production and improved food security in climate-vulnerable smallholder settings.

The authors' abstract, as published at the source. Discover Sustainability, 2026 · DOI ↗