a1 Professor of Economic History at Oxford University and Fellow of Nuffield College, New Road, Oxford OX1 1NF, U.K. E-mail: firstname.lastname@example.org.
A biological model of nitrogen in agriculture is specified for early modern England and used to analyze the growth in grain yields from the middle ages to the industrial revolution. Nitrogen-fixing plants accounted for about half of the rise in yields; the rest came from better cultivation, seeds, and drainage. The model highlights the slow chemical reactions that governed the release of the nitrogen introduced by convertible husbandry and the cultivation of legumes. However efficient were England's institutions, nitrogen's chemistry implied that the English agricultural revolution would be much more gradual than the Green Revolution of the twentieth century.
I thank Liam Brunt, Michael Edelstein, Knick Harley, John Hatcher, Fridolin Krausmann, Joel Mokyr, Patrick O'Brien, Robert Shiel, Colin Thirtle, and the editor and referee of the Journal for very helpful discussions and comments as the work progressed. An early version of the article was presented to the Economic History Society Annual Conference in 2004, and I am grateful to the participants of that session for the observations. All remaining errors and omissions are mine. For research support, I thank the Team for Advanced Research on Globalization, Education, and Technology (funded by the Social Sciences and Humanities Research Council of Canada) and Global Price and Income History Group (funded by the U.S. National Science Foundation).