Is Intercropping Viable in Rainfed Olive Systems? A Systematic Review and a Scope-Weighted Multilevel Analysis

Abstract

Rainfed olive groves across the Mediterranean basin are increasingly threatened by prolonged droughts, soil erosion, shifting climate patterns, and lower profit margins, which undermine their long-term yields and viability. Incorporating agroforestry practices, specially intercropping, may have potential to optimize resource allocation, improve land productivity, and sustainability. This is the first systematic quantitative synthesis specifically focused on rainfed olive–annual crop intercropping across the Mediterranean basin, evaluating its impacts on land-use efficiency, component crop yields, and agronomic performance metrics. The final analysis included 25 studies spanning nine Mediterranean countries, covering a period from 2009 to 2023 under annual rainfall ranging from 164 to 1052 mm. Intercropping produced overall Land Equivalent Ratio (LER) values of 1.92 for above-ground biomass and 1.76 for grain yield, yielding a mean LER of 1.84. Legumes (LER = 2.08–1.89) showed better results than cereals (1.96–1.58). On average, companion crop relative yield and olive relative yield reflected stable co-existence, with intercropping systems showing clear evidence of facilitative dynamics. These findings demonstrate that intercropping is a viable agronomic strategy for optimizing rainfed olive production systems, enhancing economic diversification and promoting sustainable agricultural intensification. Future research should prioritize long-term field trials across a broader geographic distribution within Mediterranean-type climates.

The authors' abstract, as published at the source. Agronomy, 2026 · DOI ↗