too little is definitely known to permit its advocacy here except as a
soil-builder in the case of poor land that is not too deficient in lime
to permit good growth. Experiments have shown that a taste for this
bitter plant can be acquired by livestock, and it is nearly as
nutritious as alfalfa when cut before it becomes coarse and woody. It
is a strong grower, sending its roots well down into the subsoil, and
its great ability to secure nitrogen from the air enables it to make a
very heavy growth of top. The yield in forage usually exceeds that of
the clovers.

Its most peculiar characteristic is its ability to thrive in a poor,
compact soil that contains little humus. It may be seen in thrifty
condition on roadsides and in waste places that seemingly would not
support other plants. Laying aside all consideration of its
possibilities as a forage crop, it will come into greater popularity as
a soil-builder on thin land. It is found usually on land of limestone
formation, and shares with other legumes a liking for lime, but it has
been grown successfully in regions that are known to have a lime
deficiency.

There are two biennial varieties and one annual. The biennial having
white blossoms is the one most commonly seen, but the smaller variety
with yellow blossoms is more leafy and palatable. The larger variety is
the better fertilizer.

The seed does not germinate readily, and 20 to 30 pounds is used per
acre. The soil should be compact, and the seeding can be made in the
spring with a cover crop, or in August by itself. Inoculation is
necessary if the right bacteria are not present. Soil from an alfalfa
field will serve for inoculation.

An effort should be made to grow sweet clover on all infertile
hillsides that are lying bare. It stops washing and paves the way for a
sod of nutritious grasses.

Rye as a Cover Crop.--As has been stated elsewhere, the plant that
stores nitrogen in its organic matter is most desirable, but the
greater part of the soil's stock of humus did not come through legumes.
Among the good cover crops is rye, both on account of its ability to
grow under adverse conditions and because it produces a large amount of
material for the soil. When seeded in the early fall, its roots fill
the soil the following spring, and the tops furnish all the material
that can be plowed down with safety. In northern latitudes it is the
most dependable of all winter cover crops, making some growth in poorly
pr