| In medieval times, farming was usually
based on an 'open field' system, each village usually having at
least three unfenced areas surrounding the village. These would
be divided into strips cultivated by the villagers, often working
as 'serfs' to the landowner. Wheat or rye would be grown in one
field, barley or oats in the second, and the third would be left
uncultivated or fallow. In the days before artificial fertilisers,
the livestock would be the source of manure to replenish the nutrients
in the soil. However, this rotation only cropped two thirds of the
cultivated land, with the crops rotating by one field each year.
|When Charles Townshend (1674 -1738) retired
from politics in 1730, he devoted his time to agricultural improvements.
Although turnips were grown in Britain, Townshend became a keen
advocate for including them within a rotational system. He introduced
a Flemish system, later developed as the 'Norfolk four-course rotation',
and also leading to him acquiring the name of 'Turnip' Townshend.
His rotation had clover, wheat, turnips and barley as the four crops
grown in rotation, the clover and turnips removing the need for
a fallow area. These additional crops also provided fodder for livestock
during the winter, an important factor where large flocks of sheep
were common. Previously many of the livestock had to be slaughtered
because of the lack of winter fodder.
|The four plots growing in the display
cage represent the crops that would be grown in rotation in the
fields included within a Norfolk four-course rotation.
- Clover, a legume, has nitrogen fixing nodules on the roots.
When ploughed in, the nitrogen becomes available for the next
- Wheat, utilising the nitrogen released by breakdown of the
- Turnips, lifted and stored as winter fodder, or sheep allowed
to feed on the crop and manure the soil.
- Barley, utilising the nutrients added by the sheep dung.
|Additional information on crop
rotation is available as a downloadable 'pdf' file.