cowpeas; the third way is to apply commercial
fertilizers.

To summarize: if we want to make our soil better year by year, we must
cultivate well, drain well, and in the most economical way add humus and
plant food.

=EXPERIMENT=

Select a small area of ground at your home and divide it into four
sections, as shown in the following sketch:

On Section _A_ apply barnyard manure; on Section _B_ apply
commercial fertilizers; on Section _C_ apply nothing, but till
well; on Section _D_ apply nothing, and till very poorly.

_A_, _B_, and _C_ should all be thoroughly plowed and harrowed.
Then add barnyard manure to _A_, commercial fertilizers to _B_, and
harrow _A_, _B_, and _C_ at least four times until the soil is
mellow and fine. _D_ will most likely be cloddy, like many fields
that we often see. Now plant on each plat some crop like cotton,
corn, or wheat. When the plats are ready to harvest, measure the
yield of each and determine whether the increased yield of the best
plats has paid for the outlay for tillage and manure. The pupil
will be much interested in the results obtained from the first
crop.

[Illustration: FIG. 13]

Now follow a system of crop-rotation on the plats. Clover can
follow corn or cotton or wheat; and cowpeas, wheat. Then determine
the yield of each plat for the second crop. By following these
plats for several years, and increasing the number, the pupils will
learn many things of greatest value.

SECTION VII. MANURING THE SOIL

In the early days of our history, when the soil was new and rich, we
were not compelled to use large amounts of manures and fertilizers. Yet
our histories speak of an Indian named Squanto who came into one of the
New England colonies and showed the first settlers how, by putting a
fish in each hill of corn, they could obtain larger yields.

If people in those days, with new and fertile soils, could use manures
profitably, how much more ought we to use them in our time, when soils
have lost their virgin fertility, and when the plant food in the soil
has been exhausted by years and years of cropping!

To sell year after year all the produce grown on land is a sure way to
ruin it. If, for example, the richest land is planted every year in
corn, and no stable or farmyard manure or other fertilizer returned to
the soil, the land so treated will of cou