Spatial Pattern of Litter Decomposition and Soil Carbon and Nitrogen Stocks in an Agrosilvopastoral System in the Cerrado Biome

Abstract Purpose This study evaluated the effects of eucalyptus trees in an agrosilvopastoral (ASPS) system on litter dynamics, CO₂ efflux, soil fertility, and soil carbon (C) and nitrogen (N) stocks, in order to understand how these factors contribute to nutrient cycling and the restoration of soil quality, comparing it with nominal pasture (NP) and native vegetation (NV). Methods Five treatments were assessed, including three locations within a nine years-old ASPS established with double-row eucalyptus planting, based on proximity to the trees: P1 (area between the double rows), P2 (2.5 m), and P3 (7.0 m). Litter deposition and decomposition and CO 2 efflux were monitored monthly for one year. Soil samples collected up to 50 cm depth were analyzed for bulk density, fertility attributes, and carbon and nitrogen stocks. Results Annual litter deposition was highest at P1 (5.85 Mg ha⁻¹ yr⁻¹), decreasing with distance from trees. Decomposition rates were highest at P3 and P1, with faster turnover (half-life ~ 203–224 days), and lowest at P2 (279 days). CO₂ efflux was highest at P1 (6.798 µmol m⁻² s⁻¹), likely due to increased soil moisture near the trees. Litter input contributed to maintaining K and P levels, despite no fertilisers being applied after the first five years of ASPS establishment. Soil C and N stocks were highest in NV (115.4 and 11.3 Mg ha⁻¹, respectively), and similar between NP (92.4 and 8.7 Mg ha⁻¹) and ASPS (89.9 and 8.9 Mg ha⁻¹). The findings highlight the role of litter in nutrient cycling and maintaining soil C and N in ASPS. Conclusion Our findings highlight the significant potential of agrosilvopastoral systems to enhance soil fertility and boost carbon and nitrogen stocks in tropical environments. However, these benefits are strongly contingent upon the effective and integrated management of both tree and pasture components. Without appropriate management practices, the full benefits of such systems may not be achieved, limiting their potential to enhance soil quality over time compared to conventional pastures and native vegetation. Graphical Abstract