Agricultural Sustainability and Open-Field Farming in England 245owned by New College Oxford in Hempton in 1624, 24 per cent of the land was
in grass leys, in Addlesbury in 1628 it was 16 per cent, and in Shutford in 1653 it
was 34 per cent (Havinden, 1961, p74). Pasture shortages by the end of the 17th
century led the commoners at Ibstock to convert two lands to grass leys for every
yardland held in the Neather Field, specifically to augment the cow pasture (Leices-
tershire Archives, DE 390/56. A yardland was an old method of describing and
crudely measuring an area of land but it varied in precise size even from parish to
parish let alone from one county or broad district to another. A rule of thumb sug-
gests that a yardland was about 30 acres or 12 hectares). At Grafton in Northamp-
tonshire in the 1720s and 1730s it was proposed that no more than one-third of
the land in the common fields should be under the plough and the rest in grass
(Northamptonshire Archives, G3883). At Lubenham in Leicestershire in 1734
four tenants renting from Samuel Wright had on average 36 per cent of their open-
field land in grass leys rather than arable crops (Leicestershire Archives, DE
2960).
One of the advantages of laying parcels of land down in temporary grass leys is
that it improves biodiversity and helps to integrate livestock and crops in a bal-
anced, ecologically sustainable manner. We say this not as a post-Brundtland ana-
lytical rationalization of an ancient system, but rather as a recognition that
historians have clearly identified a custom and practice in operation that can now
be presented in modern terms. Moreover, it stands in contrast to other agricultural
systems which were more land abundant than England. We have in mind here the
kind of settlement history in 19th-century North America where settlers moved on
to new ground once they had exhausted the old ground since that was automati-
cally a way of recovering biodiversity lost through soil exhaustion. In the mean-
time the exhausted ground took 20 or more years to recover through natural
regenerative means. There was a limit to the extent to which such practices could
prevail, a limit that was reached many generations ago in England. Instead con-
vertible husbandry became the solution.
The second means of adjusting the terms of trade between crops and animals
was through piecemeal enclosure of small areas of the open fields, usually in the
period under study and for the geography we have identified, for conversion to
permanent pasture. Typically this occurred at the edges of parishes remote from
the core of arable activity, on land which because of its location may have been
starved of manure and the very best husbandlike attention. These old enclosures
ranged from bite-sized pieces to very extensive but mostly contiguous stretches of
land (Thomas, 1933, p79; Swales, 1937, p245; Turner, 1980, pp137–141; Hall,
1995, p22). Many of these intakes from the communal lands probably began as
arable ley grounds located at the fringes of the open fields or in reasonably com-
pact blocks that did not interfere with the general farming of the arable field
(Hoskins, 1957, pp160–164). Whatever their origin, these enclosures came to be
managed outside the open-field system. At Hallaton, Leicestershire, in 1707, 36
per cent or 796 acres (322 hectares) of the village was enclosed in this fashion leav-
ing the remainder open (Leicestershire Archives, DE 339/340). Out of 932 acres