amount of hay at will put an end to the
absolute scarcity of manure--the limiting factor in English
agriculture from the beginning. And the comparative ease with which
the artificial grasses could be made to grow did away with the need
of waiting ten or fifteen years, or perhaps half a century, for
natural grass to cover the fields and restore their productiveness.

Only with the introduction of grass seeding did it become
possible to keep a sufficient amount of stock, not only to
maintain the fertility of the soil, but to improve it steadily.
The soil instead of being taxed year after year under the heavy
strain of grain crops was being renovated by the legumes that
gathered nitrogen from the air and stored it on tubercles
attached to their roots. The deep roots of the clover penetrated
the soil, that no plow ever touched. Legumes like alfalfa,
producing pound by pound more nutritious fodder than meadow
grass, produced acre by acre two and three times the amount, and
when such a field was turned under to make place for a grain
crop, the deep and heavy sod, the mass of decaying roots, offered
the farmer "virgin" soil, where previously even five bushels of
wheat could not be gathered.[143]

As the value of these new crops became generally recognized, some
effort was made to introduce them into the regular rotation of crops
in the fields which were still held in common, but, for the most part,
these efforts were unsuccessful, and new vigor was given to the
enclosure movement. Frequently persons having no arable land of their
own had right of common over the stubble and fallow which could not be
exercised when turnips and clover were planted; for reasons of this
sort, it was difficult to change the ancient course of crops in the
open fields. For example, late in the eighteenth century (1793) at
Stiffkey and Morston, the improvements due to enclosure are said to
have been great, for:

being half-year land before, they could raise no turnips except
by agreement, nor cultivate their land to the best
advantage.[144]

At Heacham the common fields were enclosed by act in 1780, and Young
notes:

Before the enclosure they were in no regular shifts and the field
badly managed; now in regular five-shift Norfolk management.[145]

At Northwald, about 3,000 acres of open-field land were enclosed in
1796 and clover was introduced. Th