Lawes, Sir John Bennet

(1814–1900) British agriculturalist: founder of Rothamsted Experimental Station.

Lawes had an amateur interest in chemistry, but after inheriting a farm estate at Rothamsted in 1834 he became an enthusiast for agricultural chemistry. He found that ground bones (‘mineral phosphates’) were effective in some fields but not in others, and soon discovered that acid treatment of bones made a universally effective fertilizer (it converts the insoluble tricalcium phosphate into soluble monocalcium phosphate, a conversion that acidic soils perform naturally). Despite bitter opposition from his mother (who was against ‘trade’) he began to make and sell ‘superphosphate’ prepared from bone or mineral phosphate and sulphuric acid, and used the profits to finance further experiments at Rothamsted. Aided by a chemist, J H Gilbert (1817–1901), much valuable work was done there, including the demonstration by 1851 that, as well as minerals, plant growth generally requires nitrogenous manure (in conflict with views). In 1889 Lawes put Rothamsted under control of a trust and its scientific studies of agriculture continued. Eight field experiments are still running there after 150 years.