Spatial Models of Topsoil Properties in Romania Using Digital Soil Mapping Techniques

The database includes the selected spatial models of soil variables for the Romanian territory derived by digital soil mapping techniques, accepted for publication in: Cristian Valeriu Patriche, Bogdan Roșca, Radu Gabriel Pîrnău, Ionuț Vasiliniuc, Spatial modelling of topsoil properties in Romania using geostatistical methods and machine learning, PLOS ONE, 2023 The database includes the selected spatial models of soil variables for the Romanian territory derived by digital soil mapping techniques. The file names indicate the soil variable and the method used for interpolation (RK – regression - kriging, EML – ensemble machine learning, GWR_OK – Geographically Weighted Regression – Ordinary kriging). The raster data is classified and saved in tif format with a resolution of 100 x 100 m. The spatial reference is Stereographic projection 1970 (Pulkovo_1942_Adj_58_Stereo_70). The soil variables are classified as follows: Variable Classes 1 2 3 4 5 5 7 pH ≤ 5 (strongly acid) 5.1 – 5.8 (moderately acid) 5.9 – 6.8 (weakly acid) 6.9 – 7.2 (neutral) 7.3 – 8.4 (weakly alkaline) 8.5 – 8.8 (moderately alkaline) EC (mS m-1) ≤ 12.75 12.76 – 16.49 16.50 – 20.04 20.05 – 24.18 24.19 – 29.11 29.12 – 35.23 ≤ 35.24 OC (g kg-1) < 7.5 (very low) 7.5 – 17.4 (low) 17.4 – 37.8 (moderate) 37.8 – 61.0 (high) > 61 (very high) CaCO3 (g kg-1) 0 (no carbonates) 1 – 10 (low) 11 – 40 (medium 1) 41 – 80 (medium 2) 81 – 107 (medium 3) P (mg kg-1) < 4 (extremely low) 4 – 8 (very low) 8 – 18 (low) 18 – 36 (medium) 36 – 72 (high) > 72 (very high) N (g kg-1) ≤ 1 (very low) 1.1 – 1.4 (low) 1.5 – 2.0 (medium 1) 2.1 – 2.7 (medium 2) 2.8 – 6.0 (high) > 6 (very high) K (mg kg-1) ≤ 40 * (extremely low) 41 – 65 * (very low) 66 – 130 (low) 131 – 200 (medium) 201 – 300 (high) > 300 (very high) Clay (%) ≤ 25 (low 1) 26 – 32 (low 2) 33 – 40 (medium 1) 41 – 45 (medium 2) ≥ 46 (high) Silt (%) < 25 (medium 1) 25 – 32 (medium 2) 33 – 40 (high 1) 41 – 50 (high 2) > 50 (high 3) Sand (%) < 15 (low 1) 15 – 25 (low 2) 26 – 35 (low 3) 36 – 56 (medium) > 56 (high) * classes not present on the Romanian territory