Crop–Livestock Integrated Systems Improve Soil Health in Tropical Sandy Soils

The degradation of pastures in tropical regions, particularly in sandy soils, poses significant challenges to sustainable agricultural practices. Crop–livestock integration (CLI) systems have emerged as a promising strategy to restore these degraded soils. This study evaluated the impact of land-use transitions on soil health in Western São Paulo, Brazil, focusing on the conversion from pasture (Urochloa brizantha) to CLI systems with U. brizantha (CLI-u) and M. maximum (CLI-m). A comprehensive set of chemicals (pH, phosphorus, potassium), physical (aggregate stability, bulk density), and biological (β-glucosidase activity, soil organic carbon) indicators were assessed across four land-use types: native vegetation (NV), pasture (PA), CLI-u, and CLI-m. The Soil Management Assessment Framework (SMAF) was applied to calculate the Soil Health Index (SHI) across three soil depths (0–0.1 m, 0.1–0.2 m, 0.2–0.3 m). At the surface layer (0–0.1 m), PA and NV exhibited the highest SHI values (0.65 and 0.63, respectively), while CLI-m showed a lower SHI (0.56). In the subsurface layer (0.1–0.2 m), CLI-m and NV presented the highest SHI values (0.66 and 0.67, respectively), whereas PA and CLI-u had lower values (0.52 and 0.58). At the deepest layer (0.2–0.3 m), SHI values in CLI systems were comparable to NV (0.56), while PA recorded the lowest SHI (0.48). These results demonstrate that land-use transitions and management practices significantly affect soil health in sandy soils. The findings underscore the potential of CLI systems, particularly those incorporating M. maximum, to enhance biological and chemical soil health indicators in tropical agroecosystems. Further refinement of CLI management strategies is essential to optimize soil health recovery in sandy soil ecosystems.