Digital Soil Mapping Dataset — Northern Kazakhstan Steppe Zone (2022–2023)

Multimodal remote sensing and soil agrochemical dataset for digital soil mapping in the steppe zone of Northern Kazakhstan. Study area: Kostanay Region, 20 farms, 81 fields, 1,085 soil samples (2022–2023). Soil properties (targets): pH, SOC (humus), NO₃, P₂O₅, K₂O, S — analyzed per GOST standards at certified laboratories. Remote sensing features: Sentinel-2 MSI (10–20 m): 10 spectral bands + 16 vegetation/soil indices × 4 seasons Landsat-8 OLI (30 m): 6 bands + 3 indices × 4 seasons Sentinel-1 SAR (10 m): VV, VH, VV/VH SRTM DEM (30 m): elevation, slope, aspect, TWI, TPI, curvatures ERA5-Land (0.1°): MAT, MAP, growing-season temperature and precipitation Derived features: GLCM textures, cross-sensor ratios, seasonal deltas, temporal statistics, spectral engineering (PCA, band ratios). CNN patches: Pre-extracted image patches (8×8 to 64×64 px) for deep learning models.