The field trial was established on 11 December 2025 at an organic farm in south-eastern Sicily, Italy (Noto, Syracuse province). The almond orchard, approximately 30 years old, consists of the cultivar Pizzuta d’Avola, planted at a spacing of 5 × 5 m (400 trees ha-1). The experiment followed a randomized complete block design with three replications. Alley crops were undersown with either barley or burr clover to establish two-layer systems, while a mixture of barley and burr clover was used to create a three-layer system. These treatments were compared with a sole almond system (single-layer). The same crop species were also cultivated in open-field plots outside the orchard to allow calculation of the land equivalent ratio (LER). Continuous measurements are planned throughout the growing season, and the first-year harvest is scheduled at the barley or burr clover flowering stage for forage production.
