Soil water management through subsurface drainage and ground cover influences yield and fruit quality of ‘Navelina’ sweet orange under semi-arid conditions

Sweet orange ( Citrus sinensis L. Osbeck) production in Mediterranean semi-arid regions is increasingly constrained by water scarcity and soil degradation, requiring improved soil management strategies to optimize resource-use efficiency without compromising fruit quality. These practices can modify soil physical conditions and root-zone processes, with direct implications for plant growth and crop performance. This study evaluated the combined effects of anti-weed mesh and subsurface drainage on yield and fruit composition in young ‘Navelina’ trees. An 18-month field experiment was conducted using six treatments differing in ground cover and drainage configuration. Treatments incorporating drainage and ground cover improved productive performance, suggesting enhanced soil conditions and more efficient use of available resources. Fruit production increased markedly under mesh treatments, reaching up to fourfold higher yields compared to the control without mesh. In contrast, control trees produced significantly larger fruits (+19%), although with lower juice yield (51.3%vs. 53.6–55.8% in mesh treatments). Subsurface drainage influenced fruit composition, with gravel-based drainage promoting the highest citric acid content (11.00 g L⁻¹), while the combination of mesh and under-row drainage resulted in the highest mineral and macronutrient concentrations. Total sugar content remained relatively stable across treatments, although slightly higher values were observed under conventional management. These results reveal a clear trade-off between fruit size and compositional quality under different soil management strategies. The integration of early-applied ground cover and subsurface drainage improved juice yield efficiency and nutrient density, highlighting their potential to enhance both productivity and agroecosystem performance in citrus systems under semi-arid conditions.