bility to appropriate nitrogen from the air has caused some
land-owners to fail in appreciation of the aid to soil fertility that
may be rendered by the grasses. One often hears the statement that they
can add nothing to the soil, and this is serious error. They add all
that may be given in the clovers, excepting nitrogen only, and that is
only one element of plant-food, important though it be. A great part of
the value of clover lies in its ability to supply organic matter to the
soil and to improve physical condition by its net-work of roots. Heavy
grass sods furnish a vast amount of organic matter which not only
supplies available plant-food to succeeding crops, but in its decay
affects the availability of some part of the stores of potential
fertility in the land.

[Illustration: A Heavy Grass Sod in New York.]

Prejudice against Timothy.--Timothy, among the grasses, is especially
in disrepute as a soil-builder, and yet its value is great. The belief
that timothy is hard on land is based upon observation of bad treatment
of this grass. There is a common custom of seeding land down to timothy
when it ceases to have sufficient available plant-food for a profitable
tilled crop, and usually this is the third year after a sod has been
broken. The seeding is made with a grain crop that needs all the
commercial fertilizer that may chance to be used. Clover may be seeded
also, and on a majority of farms it fails to thrive when sown. If
clover does grow, the succeeding crop of timothy may be heavy. If
clover does not grow, the timothy is not so heavy. The seeding to grass
is made partly because a tilled crop would not pay, and partly because
a hay crop is needed. It comes in where other crops cannot come with
profit, and it produces fairly well, or very well, the first year it
occupies the ground by itself. With little or no aid from manure or
commercial fertilizer, it adds much to the supply of organic matter in
the soil, and it produces a hay crop that may be made into manure or
converted into cash.

If the sod were broken the following spring, giving to the soil all the
after-math and the mass of roots, its reputation with us would be far
better than it is. This would be true even if it had received little
fertilizer when seeded or during its existence as a sod, not taking
into account any manure spread upon it during the winter previous to
its breaking for corn. But the rule is not to break a grass sod when it
is fair