Performance variability of irrigated sugar crops reveals management-driven water productivity gaps

This study quantified water use, yield, and economic performance of irrigated sugarcane in Egypt and India, and sugar beet in Egypt. Satellite-based evapotranspiration (IrriWatch®), field measurements, and farm-level economic data were integrated to estimate green, blue, and grey water footprints, as well as physical and economic water productivity. Results show substantial differences across crops and irrigation systems: flood-irrigated sugarcane in Egypt received ∼ 33,000 m 3 /ha, drip cane ∼ 20,000 m 3 /ha, and center-pivot sugar beet ∼ 11,000 m 3 /ha, blue water footprints ranging from 128 m 3 /ton (pivot beet) to 620 m 3 /ton (Indian furrow cane). High nitrogen inputs increased grey water footprints and nitrate leaching risk. Regression models explained 67–68% of water productivity variability, with irrigation type, nitrogen rate, and applied water as significant drivers; particularly reference evapotranspiration, remained statistically significant but exerted a comparatively smaller effect, indicating that management, rather than agro-climatic constraints, primarily drives performance. Data Envelopment Analysis applied to 333 individually surveyed fields revealed that Egyptian sugar beet fields significantly outperformed Indian sugarcane fields on all efficiency metrics. Small, fragmented holdings in India were identified as a key structural barrier due to widespread increasing returns to scale. By adopting pressurized irrigation and site-specific nitrogen management, policymakers and farmers can bridge productivity gaps and ensure regional water security without sacrificing sugar production targets.