Precision irrigation as a strategic tool to preserve Aglianico terroir and grape quality under climate change conditions

Abstract

Climate change poses a significant threat to viticulture, particularly for prestigious, terroir-driven varieties like Aglianico in Southern Italy. As rising temperatures and drought alter the environmental interactions between soil, plant, and climate, there is a growing risk that the resulting wine will lose its traditional typicity. This study evaluates the implementation of precision irrigation not merely as a rescue intervention, but as a strategic tool to modulate vine physiology and preserve oenological quality.

A three-year experiment (2023–2025) was conducted in a 2-hectare Aglianico vineyard in Montemiletto, Italy, comparing two treatments: Rainfed (RF) and Controlled Deficit Irrigation (CDI). In the CDI treatment, a remotely managed drip system regulated water supply to maintain leaf water potential (LWP) between -1.3 and -1.45 MPa. The study utilized environmental monitoring, UAV multispectral imaging, and physiological measurements to assess vine performance and grape composition.

Results indicated that RF vines experienced significantly higher water stress, with LWP values increasing by 14–26% compared to CDI vines across the observed seasons. This stress corresponded to a yield reduction of 10–20% in the rainfed vines. Biochemically, the strategic application of water proved critical in mitigating heat-induced acid degradation. Irrigated grapes maintained approximately 30% higher malic acid and 15% higher total acidity compared to RF grapes. Furthermore, while RF grapes exhibited higher anthocyanin concentrations, the CDI treatment resulted in a better metabolic balance, reducing Total Soluble Solids (TSS) by about 4% to prevent the excessive gap between technological and phenolic maturity often caused by water stress.

In conclusion, precision irrigation demonstrated a capability to stabilize grape quality against climatic variability. By actively managing the vine’s water status, the CDI strategy fostered a more controlled ripening pattern, ensuring the production of wines that continue to express their distinctive terroir identity despite increasingly unpredictable environmental conditions.

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Acknowledgments

We thank Agritech National Research Center funded within European Union Next-GenerationEU program (The National Recovery and Resilience Plan, mission 4, component 2, investment 1.4-D.D. 1032 del 17/06/2022, project CN00000022) for financing this research.