Effect of cover crop management system on olive orchards: Soil morphological and micromorphological alterations

Olive production in Brazil occurs in regions with shallow soils and steep slopes, requiring sustainable soil cover crop management to improve the surface layer and enhance soil structure. This study aimed to evaluate the morphology of Dystrudepts under different cover crop management systems through field observations and micromorphological analyses. An eight-year study was conducted to assess the effects of five cover crop management systems on soil structure and microstructure. Morphological descriptions were performed on five soil profiles, and undisturbed samples were collected from the vertical face of each pit for micromorphological analysis and thin-section interpretation. The treatment with olive trees and jack beans, followed by managed spontaneous vegetation, enhanced soil structure, total porosity, A horizon thickness, and therefore minimized soil loss over six years. The presence of illuvial clay film fragments highlights the role of erosive forces in detaching and redistributing fine soil particles within the surface layer. Overall, cover crop management systems significantly influenced soil structural and microstructural properties, demonstrating their importance in maintaining soil integrity and mitigating degradation in olive-orchard regions. • Cover crops increased A-horizon thickness in olive orchard soils. • Cover crops improved soil structure in tropical Dystrudepts under olives. • Micromorphology revealed clay illuviation and organic matter incorporation. • Cover crops alleviated subsurface compaction and improved porosity. • Long-term management altered soil morphology and microstructure dynamics.