Sustainability of olive growing in the Mediterranean area under future climate scenarios: Exploring the effects of intensification and deficit irrigation

Olive orchards represent a key agricultural system with high economic and environmental prominence. Expected future climate tendencies over the Mediterranean could threaten the sustainability of such strategic tree crop. This study evaluates the productive and environmental performance of olive orchards under different climate change scenarios and management strategies across the main olive-farming regions over southern Europe using the process-based model OliveCan. Simulations were performed for low density LD (100 trees ha-1), high density HD (400 trees ha-1) and super high density SHD (1650 trees ha-1) olive orchards over baseline period (19802010) and future scenarios (2041-2070 and 2071-2100 for RCP4.5 and RCP8.5). Results showed that the future increase in CO2 concentration may compensate the negative effects of higher evaporative demand and diminished water supply resulting in an enhancement of water use efficiency and carbon capture potential in olive orchards. Irrigation requirement for the maximum productivity are expected to increase by 5-27%. Moreover, rainfed low density orchards will be the most vulnerable to expected climate changes, in particular in the driest areas. In fact, a decrease in yield up to 28 % with an increase in its interannual variability of 20 % is expected over the Iberian Peninsula while yield increased up to 26 % over the centre of the Mediterranean. Deficit irrigation and intensification will improve olive orchard productivity and carbon sequestration capacity. Besides, the decrease in winter chilling is not expected to be enough to produce significant flowering anomalies or failures over the study area. Even though findings of this research showed that olive orchards may benefit from future conditions, assessment of management alternatives at local scale will be a must for a better adaptability of olive orchards.