Soil carbon, nitrogen, isotopic composition (δ¹³C), fertility and texture under different land-use systems in northeastern Amazonia (AF and AW climates).

This dataset contains soil physical, chemical and isotopic data collected under different land-use systems located in northeastern Amazonia, representing two Köppen climate types (AF and AW). Soil samples were collected from trenches down to 100 cm depth at eight intervals (0–5, 5–10, 10–20, 20–30, 30–40, 40–60, 60–80, 80–100 cm). The dataset includes measurements of soil bulk density, carbon (C) and nitrogen (N) concentrations, conventional C and N stocks, and equivalent soil mass–corrected stocks for both 0–30 cm and 0–100 cm. Isotopic composition (δ¹³C) was determined to estimate the relative contribution of C₃- and C₄-derived carbon across land-use systems and depths. Soil fertility data include pH, organic matter, macronutrients (P, K, Ca, Mg), exchangeable acidity (Al, H+Al), sum of bases, effective CEC, CEC at pH 7.0, base saturation (V%) and aluminum saturation (M%). Soil texture (coarse sand, fine sand, silt and clay) was also determined.The dataset supports analyses of land-use change impacts on soil carbon and nitrogen dynamics, isotopic signatures, soil fertility, and texture in tropical landscapes. All variables are organized into separate tabs (bulk density, carbon stock, nitrogen stock, δ¹³C for AF and AW climates, soil fertility, and soil texture), facilitating reproducibility and reuse.