THE FALLOWS 79
mained at an average of about 12^ bushels for many years, "and
will in the future diminish very slowly, if at all "^ Few medieval
holdings could have been starved to a greater extent than this%
and if the "exhaustion" theory is to be sustained it will require
better evidence than has yet been produced in its support. The
comparatively low yield of medieval cropping is sufficiently ac-
counted for by the poor supply of manure, the lack of variety of
crops and the inefficient methods of preparing the soil at the
disposal of the medieval husbandman.
With these difficulties in mind let us assume that we are
dealing with an energetic and reasonably successful peasant who
has thirty acres under the three-field system, and follow him
throughout the year as he works upon them. First, the ten acres
of fallow. These present a comparatively simple problem. As
we have seen, they form part of one of the common fields and
are open to all to feed upon, and the peasants turn their cattle out
upon them, in part to manure them, in part to graze upon the
scanty vegetation that they supply, each acre of which should be
sufficient to support two sheep at the very least.2 From time to
time, however, preparations for the coming crop have to be
made, and the field is ploughed on three occasions. April is a
good time for this first ploughing, Walter of Henley tells us, for
then the earth breaks up well, and it is good to do it again in a
couple of months' time, taking care not tQpplough too deeply, but
just sufficiently to destroy the thistles.3 After this it can be left
until the autumn, and then in October it is ploughed for the last
time before the winter corn is sown. This time the plough should
go some two finger lengths deeper than before, "then the plough
will find sure ground, and clear and free it from mud, and make
fine and good ploughing".4
The other two fields, however, took up much of the peasant's
time. In January he could do little upon them, save perhaps
cart out manure or spread marl ready to be ploughed in as soon
as the weather was suitable. These were his main means of
1 A. D. Hall, The Book of the Rothamsted Experiments (1905), 37, as quoted
by Lennard.
2 Walter of Henley, 143.
3 Ibid, n, 13. Fitzherbert advises two "stirrings'*: one in June and a
second early in September.
* Ibid. 15.