grows are broken up at some period short of ten years, and not
infrequently at the end of five or six years. When thus grown, it
becomes a rotation plant, though grown in what may be termed long
rotations. But even in the West, where, under irrigation, it may be
grown for a quarter of a century or even for a longer period without
renewal, it may be used when desired in short rotations. In such
situations it grows so readily and becomes established so quickly, that
the fields may be broken with a view to alternate with other crops at
the end of the second year, or of any year subsequently from the sowing
of the seed that may be desired. Alfalfa in these soils will serve even
better than medium red clover in such situations, since while it is
growing, it will produce more hay or soiling food, and consequently
should excel the former in the fertility which it makes available.

East of the Mississippi and north of the Ohio River, alfalfa will
frequently follow cultivated crops, as corn, potatoes and field roots,
and when the fields are broken, it will be followed by crops other than
legumes. On many soils the influence which this crop has on relieving
the surface soil from excessive moisture, through channels opened into
the subsoil by the decaying roots, is so helpful as to considerably
stimulate production in addition to the fertilizing influence which it
exerts directly. Particularly good crops of corn, the small cereal
grains, and even field roots may be grown after alfalfa.

On soils east of the Mississippi and south of the Ohio, the rotation
will be somewhat similar. But on Southern soils alfalfa will frequently
follow immediately crops especially grown to be plowed under as green
manures for the benefit of the alfalfa. These crops include cow peas,
soy beans, crimson clover, and to a limited extent, burr clover. It will
also be followed frequently by crops of cotton and other non-leguminous
plants, the growth of which in the United States is confined to the area
now being considered.

In the area west of the Mississippi and east of the semi-arid region
beside the mountains, alfalfa may follow the small cereal grains, and
may in turn be followed by them and also by millets. It may also follow
and precede corn, or the non-saccharine sorghums, where the climatic
conditions are suitable for growing the latter.

In the irrigated regions of the West, alfalfa may be made to serve
almost any purpose in the rotation that