Mark Overton the historian argues that the role of the 'Great Men' as pioneers and innovators in agricultural change has been exaggerated (Overton, 2004)
Names such as Jethro Tull, Lord Townshend, Arthur Young, Bakewell, Coke of Holkham and the Collings were not so revolutionary as usually taught. 'Turnip' Townshend was only a boy when turnips were first grown on his estate; Jethro Tull was not the first person to invent the seed drill, which was in any case slow in introduction. Coke of Holkham (four course rotation) was a self-publicist who overplayed his not always suitable method.
The reason for agricultural intensity in growing crops was a combination of need: an ever rising population with the greater use of nitrogen in the soil.
There was, in any case:
Most crucially converting nitrogen into nitrates in the soil allowed crops to grow more intensively:
Overton, M, Agricultural Revolution in England 1500 - 1850 [Online], World Wide Web, URL:
http://www.bbc.co.uk/history/society_culture/industrialisation/agricultural_revolution_01.shtm, to agricultural_revolution_01.shtm
[Last Accessed 3 November 2004, 23:00], BBCi.