Soil carbon stock and physical attributes under land‐use chronosequence in the Brazilian Cerrado

Abstract

Land‐use changes impact soil physical quality and carbon stocks. Most studies evaluating the conversion of native Brazilian Cerrado to agriculture focus on surface soil layers (up to 40 cm), with fewer examining deeper layers (0–100 cm). This study assessed the impacts of different land‐use systems on soil physical attributes and soil organic carbon stock (SOCS) in a Latossolo Vermelho (Oxisol) following the conversion of native Cerrado vegetation. The evaluated areas consisted of native Cerrado, a chronosequence of no‐tillage systems (NTS) managed for 2, 11, and 20 years, a silvopastoral system (SS) managed for 37 years, and a degraded pasture established for nearly 50 years. Soil samples were collected from the depths of 0–10, 10–20, 20–40, 40–60, 60–80, and 80–100 cm to determine physical attributes related to soil porosity and aggregation and to calculate SOCS. The SS exhibited the greatest potential to provide ecosystem services, due to improved soil porosity, aggregation, and carbon storage (146.6 Mg ha ⁻¹ ). The NTS also presented a higher SOCS (ranging from 111.5 to 112.9 Mg ha ⁻¹ ) than the Cerrado (102.8 Mg ha ⁻¹ ), although negative changes in physical attributes were detected in the long‐term. Across all evaluated land‐use and management systems, approximately half (44%–53%) of the carbon in the 1‐m‐deep soil profile was stored below 40 cm, highlighting the significant contribution of subsurface soil layers to organic carbon stocks.