that already enjoyed a considerable surplus of grain. It
also required the development of a new type of harness.
Horses cannot be yoked like oxen without constricting
their windpipes, and attaching the plow to their withers
or tail is not only cruel but also woefully ineffective.
The modern harness, without which a draft horse is vir-
tually useless, appears to have been developed in Asia
and introduced to Europe around the year 800.
A fringe benefit associated with the increased use
of draft animals was the greater availability of manure.
Medieval peasants knew that manure greatly increased
the fertility of soils, just as they knew that marl could
be used to reduce soil acidity and that soils could be
mixed to improve workability or drainage. All of these
techniques were labor-intensive. Substantial quantities
of manure were required to fertilize even a moderately
sized field, and though draft animals were numerous af-
ter 1100, livestock production for meat remained mod-
est until the second half of the fourteenth century.
Perhaps the most important advance in this area
was the Frankish invention of the scythe, which largely
replaced the sickle and permitted large-scale haying
and the stall feeding of cattle. The cattle were kept for
meat and dairy products, and their manure was care-
fully collected and spread on the fields. However,
stockraising is a fundamentally inefficient use of land.
Vegetable crops suited for direct human consumption
fed more people from the same acreage. In marginal
economies where even intensive cultivation provides
modest yields, animal protein is a luxury. Supplies of
manure, though improved, were therefore limited and
were probably applied most frequently to household
gardens and other small plots. The use of human waste
as fertilizer, though common in Asia, was apparently
rare in the West.
Larger fields could retain their productivity only by
being left fallow or through crop rotation. Yields by
modern standards remained poor, but they were a great
improvement over those of Charlemagne’s time.
Whereas harvesting one-and-a-half grains for every
grain planted was once common, harvesting four or five
became possible. Theoretically, the maximum yield of
wheat from an unfertilized field is about twelve bushels
per acre. Peasants in the thirteenth century probably
averaged about half this amount from fields that today
produce sixty bushels per acre or more, but five to
seven bushels per acre was a substantial improvement
over times past (see table 10.2).
The improvement of yields, the extension of culti-
vation into new areas, and the reduction in the amount
of labor required to produce a given quantity of food
produced consistent surpluses of crops in those areas
where they grew best. This in turn led to agricultural
specialization. The Beauvaisis or the Ile de France, for
example, were ideal for the cultivation of wheat but
produced only small quantities of inferior wine. Parts of
Burgundy produced excellent wine but relatively mea-
ger stands of wheat. Landholders found that they could
improve their revenues as well as their standard of liv-
ing by selling off surpluses and using the profits to pur-
chase commodities that grew poorly, if at all, on their
own manors. In time, whole regions were devoted to
the cultivation of grains, while others specialized in
wine, olives, or other commodities. The great wine-
growing areas were planted for the most part in the
twelfth century, usually along navigable rivers such as
the Loire, the Rhone, or the Rhine. Corking and bot-
tling had not yet been invented, so wine was shipped in
casks that were too heavy to transport easily on land.180 Chapter 10
Illustration 10.3
The Heavy Wheeled Plow.This illustration from an early
sixteenth-century prayer book shows a typical wheeled plow in
operation. It is not much different from those introduced in the
ninth and tenth centuries. Note the arrangement of the harnesses
on the team of horses.