Rothamsted (rŏth´əmstĬd), world's oldest and England's most important agricultural experiment station, now the main center of the Institute of Arable Crops Research (IACR). It was founded in 1843 by John Bennet Lawes on his estate at Harpenden, in Hertfordshire, where he had been experimenting with fertilizers. In 1842 a patent had been granted him for the development of superphosphate—bone meal, or calcium phosphate, treated with sulfuric acid—an artificial fertilizer, which his factory soon produced in large quantities. The station continued experimenting with fertilizers and expanded its activities to include crop-production studies and animal nutrition experiments. Expansions started in 1902 provided new facilities and added to the staff botanists, bacteriologists, chemists, and writers, which increased the value of the station to Great Britain's varied agricultural interests, distributed as they were throughout the world. In 1934 a public appeal brought forth the funds needed to buy the grounds used by the station. The experimental work, which had once been financed entirely by Lawes, came to be sustained by government grants, supplemented by private contributions. In 1987 Rothamsted, the Long Ashton Research Station, and Broom's Barn Experimental Station merged to form the IACR. An important function of the institute now is the training of postgraduate research workers.