and complete. As has been intimated, where
water is excessive, in a climate which in winter or spring is
characterized by alternations of freezing and thawing, the plants will
either have the roots snapped asunder, or they will be gradually raised
out of the ground. This will only happen in soil with a subsoil more
retentive than is compatible with well-doing of the highest order in the
plants. The danger from this source is greatest during the first winter
after sowing the plants, as then the roots are not really established.
The only remedy for such a contingency is the draining of the land.

Some reference has also been made to injury done through ice, where it
collects in low places in land. The destructiveness of the ice depends
on its thickness and its nearness to the ground. When it rests upon the
ground for any considerable time the plants die. If, however, water
intervenes, the plants may live when the submergence is for a limited
time. One instance is on record in Onondaga County in New York State, in
which alfalfa survived submergence for a considerable period under a
thin sheet of water covered by three inches of ice, but when growth came
it was for a time less vigorous than normal.

Floods in warm weather are greatly injurious to alfalfa. The extent of
the injury done increases with increase of depth in the waters of
submergence, increase in stagnation in the waters, and increase in the
duration of the period of overflow. Stagnant water sooner loses its
dissolved nitrogen; hence, the plants cannot breathe normally. The harm
done, therefore, by floods in each case can only be known by waiting to
see the results. These summer floods always harm the crops temporarily,
and in many instances kill them outright. Occasional periods of overflow
should not prevent the sowing of alfalfa on such lands, since on these
it is usually not difficult to start a new crop, but the seed should not
be sown on such lands when overflow occurs at such a season. When it
occurs in cool weather and quickly subsides, it may be possible to grow
paying crops of alfalfa.

In some areas grasshoppers are a real scourge in alfalfa fields. Because
of the shade provided by the ground and the influence which this exerts
in softening it, they are encouraged to deposit their eggs and remain so
as to prove a source of trouble the following year. It has been found
that through disking of the land both ways after sharp frosts have come
is greatl