and mature seed so profusely that when the plants die
and partially decay seed may sometimes be collected in hollows, into
which it has been driven by the wind. It is more commonly sown in the
burr form, the form in which it is usually gathered. The more common
method of saving the seed, as given by Mr. A. H. Beattie of Starkville,
Mississippi, is to first rake off the dead vines so as to leave the
burrs on the ground and then sweep them together with a suitable wire or
street broom. It is then lifted and run through two sets of sifters of
suitable mesh by hand to remove the trash swept up in gathering the
seed. It is probable that other methods more economical of labor are yet
to be devised when harvesting the seed crop. As much as 100 bushels of
burrs have been obtained from an acre, but that is considerably more
than the average yield of seed.

=Renewing.=--Since this plant is an annual, it cannot be renewed in the
sense in which renewal is possible with a perennial. But as has been
shown above (see page 294), it may be grown annually for an indefinite
period in the same land and without re-sowing by hand. It has also been
shown that by sowing the seed in certain crops at the proper season,
from year to year, it may be made to grow from year to year where the
rotation will admit of this. (See page 295.) When the ground is well
stored with seed, the plants will continue to come up freely in the soil
for at least two or three years, even without any re-seeding of the
land.

=As a Fertilizer.=--The growing of burr clover exercises a beneficial
influence on the land. Its value for this purpose, since it can be grown
as a catch crop, is probably greater than its value in providing food
for stock. Like all plants that are more or less creeping in their habit
of growth, it shades the soil and keeps it moist, which, in conjunction
with the influence of the roots, puts it in a friable condition. When
the plants grow rankly, it is not easy to bury them properly with the
ordinary plow, but in such instances, if cut up with a disk harrow, the
work is facilitated. The plants quickly die down so as to make plowing
easily possible, but the aim should be to have such decay take place
within the soil rather than above it.

CHAPTER XI

SWEET CLOVER

Sweet clover is so named from the sweet odor which emanates from the
living plants. It is of two species. These are designated, respectively,
_Melilotus alba_ and _Melilotus