Comparative assessment of agroforestry performances between pea and barley intercropping with olive tree under semi-arid Mediterranean conditions

Olive-based agroforestry could provide a sustainable solution, particularly through the implementation of cereal and legume crops in intercropping with olive trees. However, the deep assessment of agrophysiological indicators between intercropped forage legumes and cereals with olive tree is poorly documented in the literature. The aim of this field research is to assess the performance of olive-based agroforestry systems by analyzing how the main agrophysiological indicators change among two contrasting intercropping arrangements of forage arable crop. Field trials were performed during two contrasting growing seasons in a young olive grove under semi-arid climate. To further enhance our understanding of olive-agroforestry performance in terms of growth and yield; multiple agrophysiological parameters were measured in arable and olive monoculture, as well as in the olive-intercropping system with two contrasting intercropping arrangements of pea and barley. The results demonstrated that olive tree canopy significantly stimulated the growth of shoot and root of intercropped barley by increasing LAI, Shoot dry biomass (+ 56%) and both root depth (+ 19%) and width (+ 26%) compared to barley monoculture. Olive-agroforestry also enhanced barley grain and protein yield (+ 58%) during both growing seasons. Agroforestry system had additional benefits in improving the vegetative growth of intercropped olive trees by increasing soil nitrogen availability. Our findings highlight also the potential benefits of intercropping olive trees with pea in improving both fruit and oil yields in olive production. Olive-based agroforestry promotes an optimized micro-climate to effectively reduce the impact of drought on intercropped barley and improves resources use by pea under optimal conditions.