Evapotranspiration, carbon dynamics and water use efficiency in a drip-irrigated olive orchard in arid coastal western South America

The primary climatic characteristic of olive cultivation in Peru is the coastal desert environment with moderate temperatures, minimal precipitation, and high atmospheric water content during the winter season. This report presents a comprehensive study on water and carbon fluxes in a drip-irrigated olive orchard in Pisco Province, Peru, addressing the current lack of information on olive physiology and water management under these environmental conditions. The eddy covariance system installed in September 2019 showed an average ET of 2.18 ± 0.38 mm d⁻¹, with seasonal variation. Drip irrigation was set at 60 m³ ha⁻¹ d⁻¹ during the growing season and reduced to half that amount in the winter. The study suggests that using deficit irrigation based on affordable dendrometry sensors could reduce water use by close to 30% while potentially preserving biomass gain and fruit yields. This could help improve water management in olive cultivation in coastal Peru.