Chemical fertilizers were not invented, they were adopted almost as soon as it became apparent that most of the Carbon, Hydrogen and Oxygen in plants came from the atmosphere but traces of other elements must come through the roots. Organic fertilizers have been used for thousands of years. Chemical fertilizers were adopted in the 1800’s after the work of Theodore de Saussure of Switzerland, Sir Humphrey Davy and Justus von Liebig Initially readily available minerals were used, especially for Nitrates and Phosphates. Bone meal became replaced by forms of Lime (Calcium Oxide).