Plant Nutrients and Future Food Supply

These huge extensions of cultivated land brought much larger grain harvests during the last decades of the nineteenth century when average wheat yields remained 

It was not Liebig, however, but an Irish doctor, James Murray (1788-1871), who became the first commercial vendor of inorganic fertilizers with his 1841 offer of liquid superphosphate made by dissolving bones in H2 04. Two years later Lawes set up a superphosphate factory at Deptford on the Thames. His fertilizer, patented in May 1842 on the same day Murray got his patent, was a virtually identical product, containing Super-Phosphate of Lime, Phosphate of Ammonia, Silicate of Potass, etc.  

William Crookes (1832-1919). Courtesy of the E. F. Smith Collection, Rare Book and Manuscript Library, University of Pennsylvania. 

Near the end of his lecture Crookes offered an eloquent summation why the fixation of atmospheric nitrogen was one of the great discoveries awaiting the ingenuity of chemists  

This unfulfilled problem, which so far has eluded the strenuous attempts of those who have tried to wrest the secret from nature, differs materially from other chemical discoveries which are in the air, so to speak, but are not yet matured. The fixation of nitrogen is vital to the progress of civilised humanity. Other discoveries minister to our increased intellectual comfort, luxury, or convenience they serve to make life easier, to hasten the acquisition of wealth, or to save time, health, or worry. The fixation of nitrogen is a question of the not far-distant future 

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