An observational assessment of soil physical, chemical, and biological attributes under contrasting land-use systems in Eastern Maranhão, Brazil

Abstract

Abstract The adoption of integrated crop–livestock production systems, together with practices such as crop rotation, crop succession, and intercropping, has increased the need for integrated approaches to assess soil health. This study evaluated soil health under contrasting land-use systems in the Cerrado region of Maranhão, Brazil. The study was conducted in 2024 at Barbosa Farm (Brejo, Maranhão), comparing integrated crop–livestock (ICL), integrated livestock–forestry (ILF), no-tillage (NT), managed pasture (MP), and native vegetation (NV). Soil samples were collected from the 0–0.10, 0.10–0.20, and 0.20–0.30 m layers to determine soil bulk density ( $$D_{b}$$ D b ), soil pH, available phosphorus (P), exchangeable potassium (K), and total organic carbon (TOC). Soil health was assessed using the Soil Management Assessment Framework (SMAF), which integrates physical, chemical, and biological indicators into standardized indices. Native vegetation exhibited the lowest soil pH (4.28 in the 0–0.10 m layer), whereas ICL showed the highest value (5.42). NT presented the highest concentrations of available P and K ( $$46.94$$ 46.94 and $$31.28{\text{ mg dm}}^{ - 3}$$ 31.28 mg dm - 3 , respectively). ILF had the highest TOC concentration ( $$24.3{\text{ g kg}}^{ - 1}$$ 24.3 g kg - 1 in the 0–0.10 m layer) and the greatest carbon stock ( $$97.2{\text{ Mg ha}}^{ - 1}$$ 97.2 Mg ha - 1 in the 0–0.30 m profile). According to SMAF, ILF (0.99) and NT (0.98) achieved the highest biological indicator scores in the surface layer, whereas ICL (0.72) and NT (0.73) showed the highest Soil Health Index values at the 0.10–0.20 m depth. Although constrained to an observational framework within commercial fields in Brejo, Maranhão, these results indicate that integrated systems and no-tillage better maintained soil health than managed pasture in sandy Cerrado soils.