Here’s a good guide from 1917 — after the Haber process was invented, but before its widespread use in the Green Revolution. https://naldc.nal.usda.gov/download

Here’s a good guide from 1917 — after the Haber process was invented, but before its widespread use in the Green Revolution. https://naldc.nal.usda.gov/download/ORC00000242/PDF https://naldc.nal.usda.gov/download/ORC00000242/PDF