Living mulch in fruit and olive orchards. A review

Sustainable weed management is a key challenge in fruit and olive orchards. Conventional practices, such as intensive weed control and monoculture, can degrade soil quality and reduce biodiversity, threatening long-term productivity. Living mulch, defined as an herbaceous soil coverage, grown alongside the main crop, represents a promising agroecological strategy for enhancing ecosystem services. However, current knowledge on living mulch in orchards remains fragmented, with studies often focusing on single ecosystem functions and providing context-dependent and sometimes contrasting results. This limits the ability to identify consistent patterns and to support practical decision-making. To address this gap, this systematic review synthesizes and integrates the available evidence on the effects of living mulch on orchard agroecosystems, focusing on weed suppression, soil fertility, biodiversity, soil physical and chemical properties, pest control, agronomic performance, and tree root system dynamics. Findings indicate that living mulch contributes to undesired species suppression (82 records), increases biodiversity and soil fertility (109 records), enhances soil microbial activity and nutrient cycling (120 records), improves soil structure and water retention (66 records), and supports beneficial insect populations for natural pest control (49 records). However, living mulch may also introduce challenges such as resource competition with fruit trees and potentially provide habitats for rodents. The magnitude of these effects varies depending on species selection, pedoclimatic conditions, and management practices. A satisfactory outcome of introducing living mulch in an orchard depends on selecting the appropriate living mulch species and management practices, as well as on shifting farmers’ perspectives to emphasize the long-term ecosystem services of living mulches rather than focusing solely on short-term crop yield. A participatory approach involving farmers is essential for optimizing living mulch integration into orchard systems. Long-term studies are needed to assess the resilience and productivity of living mulch-based management strategies over time.