Soil Organic Carbon and Total Nitrogen Content in the Brazilian Amazon

This dataset contains chemical and physical soil properties from 12 sites in the Brazilian Amazon (Pará), including 10 cacao-based agroforestry systems (CAFSs) and 2 secondary vegetation (SV) control areas. Soil samples were collected at four depths (0–10, 10–20, 20–30, and 30–40 cm) and analyzed for soil organic carbon (SOC), soil organic matter (SOM), total nitrogen (TN), C:N ratio, pH in water (1:2.5), and particle-size distribution (sand, silt, and clay), all expressed in g·kg⁻¹ where applicable. Each value represents the average of triplicate laboratory analyses from composite samples derived from five subsamples per depth and site. The dataset is provided in .xlsx and .csv formats, with columns identifying site ID, geographic coordinates, land-use type (CAFS or SV), soil depth, and all measured parameters. These data were used to assess the long-term impacts of cacao-based agroforestry on soil fertility and edaphic properties in highly weathered Amazonian soils.