Fig. 1: Agricultural productivity and key parameters of the world’s four major black soil regions.

a Contribution of each region to global production of key staple and oilseed crops. Values represent the percentage of global output sourced from black-soil cropland within each region. Region A: Ukraine and European Russia; B: Northeast China; C: United States and Canada; D: South America. b Regional comparison of agricultural inputs (fertilizer, irrigation, and pesticide), subsoil compaction susceptibility index (SCSI), and key soil properties (bulk density, soil organic carbon, pH). Values are cropland-weighted means derived from publicly available global datasets. We integrated multiple datasets to characterize cropland conditions across four major black-soil regions. Cropland extent was derived from Historic Land Dynamics Assessment Plus (HILDA⁺), and black-soil boundary were compiled from the USDA NRCS Global Soil Type Database (Ukraine/European Russia, North America and South America) and China’s Second National Soil Survey (Northeast China). All layers were rasterized, reprojected and resampled to the HILDA⁺ grid, then intersected to delineate cropland within each black-soil region. Crop harvested area (SPAM v2.0, 2020) was used to compute total harvested area and dominant crop shares. Agricultural inputs were summarized from global products: fertilizer (Global Crop Specific Fertilization dataset for 1961 to 2019), irrigation (GMIE, a global maximum irrigation extent and central pivot irrigation system dataset), and pesticides (PEST-CHEMGRIDS). SCSI and SoilGrids 2.0 soil properties were aggregated over cropland for each region. Detailed data sources and processing steps are provided in Supplementary Note 1.