y.

Where the clovers grow well they make excellent cover crops as well as
green manure crops. The chief difficulty with them is that of
obtaining a good stand in a dry midsummer. The mammoth red and the
medium red clovers are probably the best of their genus on the heavier
soils, while crimson clover is best on sandy soils and where it will
grow, on the lighter gravel loams. The latter is especially well
adapted to building up run down sandy soils. Although it is somewhat
easier to secure a stand of this clover, alsike does not grow rank
enough to make a good cover or green manure crop. Most clovers are
deep rooted plants and therefore great soil improvers physically as
well as being great nitrogen gatherers. The amounts of seed required
per acre for the different kinds are about as follows: mammoth fifteen
to twenty pounds; red (medium) twelve to fifteen pounds; crimson
twelve to fifteen pounds; and alsike ten to twelve pounds.

Where it can be readily and successfully grown alfalfa is really a
better cover and green manure crop than the clovers. It is deeper
rooted, makes a better top growth, and therefore adds more nitrogen
and more humus to the soil than the clovers. It cannot be recommended
for common use, however, as it is so difficult to grow except under
favorable conditions. It requires a more fertile soil than clover, a
soil with little or no acidity, good drainage, and usually the soil
must be inoculated. Only where these conditions prevail can alfalfa be
generally recommended.

Vetch is an excellent cover and green manure crop, forming a thick,
close mat of herbage which makes a good cover for the soil. It is very
quick to start growing and a rapid grower in the spring. It also adds
larger quantities of nitrogen. The hairy or winter vetch lives through
the hard freezing winters. Summer vetch, although an equally good
grower, is killed by freezing. One bushel of seed is required per acre
and the seed is expensive, which is the greatest objection to the use
of this excellent crop.

Two other less well known and used leguminous crops are well worth
trial as cover crops--soy beans in the North and cow peas in the
South. Both are great nitrogen gatherers and as they are rank and
rapid growers add large quantities of humus to the soil. Under
favorable conditions they will cover the ground with a perfect mat of
vegetation in a very short time. Being larger seeded, it is
considerably easier to obtain a stand o