Sweet clover requires a well-settled and firm seed bed, with just
sufficient loose soil on the surface to permit the seed to be well
covered. When the seed is sown in the spring on winter grain the
seed bed usually is in good condition. At this season of the year the
seed may be sown, so that it will be covered by freezing and thawing
weather. It may be sown also when the ground is in condition to
cultivate and then may be harrowed or drilled in. When the seed is sown
with spring grain the seed bed is not as firm as it should be for the
prompt germination and establishment of the young clover plants. If
sown in this manner the soil should be worked into a fine condition and
firmed as much as possible. It is good practice to roll the ground with
a corrugated roller after seeding. Better stands are usually obtained
by seeding on fields that have been disked and harrowed than on those
that have been plowed.
When sweet clover is seeded without a nurse crop it should not be sown
on freshly plowed land which has had no opportunity to settle. The land
preferably should be plowed several months before the seed is to be
sown, and then worked at intervals with soil packers or harrows. Double
disking and harrowing just previous to seeding are to be strongly
recommended in preference to plowing at this time.
When sweet clover is to be seeded in the fall on grain stubble, the
ground should be disked and worked into good condition as soon as the
grain can be removed. If the seed is sown immediately the field should
be rolled after seeding.
Fall-plowed ground ordinarily makes an ideal seed bed for spring
seeding. Soil which has been previously planted to a cultivated crop,
such as corn, is usually put in sufficiently good condition for
sweet clover by disking. Good success has been attained by merely
broadcasting the seed on sandy soil and scratching it in with a harrow.
Such a seed bed appears to be ideal when the seed can be covered
sufficiently to insure plenty of moisture. It must be remembered that
young sweet-clover plants are not drought resistant and that every
precaution should be taken in seasons of drought or on laud which
drought affects badly to so prepare the seed bed that the largest
quantity of moisture will be conserved.
Excellent stands have been obtained at times by double-disking native
prairie sod and either covering the seed with a harrow or sowing it
with a drill.