For many years the history of English agriculture since the sixteenth century has been dominated by rival notions of an ‘agricultural revolution’: a period when changes in agricultural output and sometimes also in the organisation of production are held to be of particular significance. While there is a general consensus that an ‘agricultural revolution’ involves technological change of some kind, there is no consensus as to what are the significant changes, nor is there any agreement over the chronology of such ‘revolutionary’ events. Despite this uncertainty, the substantive issues of the debate remain of central importance to understanding the development of both English agriculture and the English economy in the three and a half centuries from 1500 to 1850. This chapter will briefly review the debate before making the case for a set of criteria appropriate for identifying an ‘agricultural revolution’.

Agricultural revolutions

Phases of ‘revolution’ have been identified for at least five periods between 1560 and 1880, and each has been characterised by a different combination of ‘significant’ agricultural developments. Yet despite these differences there is a remarkable consensus, which stretches back to the earliest writing on the subject, that the essence of the ‘agricultural revolution’ was an increase in cereal yields per acre, that is the amount of grain that could be produced from a given area of land sown with a particular crop. The mechanism for raising yields was described by William Marshall in 1795: ‘No dung – no turnips – no bullocks – no barley – no clover – nor … wheat.’