Siora Open Soil Nutrient Dataset – Ukraine (2000, 2010, 2020)

This dataset contains direct satellite-derived estimates of soil nutrient properties for Ukraine at ~250 m resolution, covering the years 2000, 2010, and 2020. Variables include Nitrogen (N), Phosphorus (P), Potassium (K), Organic Carbon (OC), and pH.   The data are derived from multispectral reflectance spectroscopy, corrected with topographic, climatic, and geological auxiliary datasets to isolate nutrient signatures. Each variable is provided as a single-band GeoTIFF (zipped), with accompanying PNG heatmaps, thumbnails, README, metadata JSON, and CC-BY 4.0 license.   Comparable laboratory references:  - pH – ISO 10390:2005 (Glass electrode)  - Nitrogen – ISO 11261:1995 (Modified Kjeldahl)  - Phosphorus – ISO 11263:1994 (Spectrometric determination)  - Potassium – USDA–NRCS (Atomic absorption after NH₄OAc extraction)  - Organic Carbon – ISO 10694:1995 (Dry combustion)   Suggested uses: nutrient trend analysis, soil health monitoring, precision agriculture benchmarking, model training and validation.