arge part of the enterprise
the cropping system must be carefully adjusted to meet the needs of
these animals. Many apparently trivial details must be considered, as
for example, whether the cropping system furnishes too little or too
much bedding for the live stock.

In considering profits the enterprise as a whole must be kept in view.
For example, if a man is producing milk, it may be cheaper, so far as
the production of milk is concerned, to allow the liquid excrement to
run to waste rather than to arrange for sufficient bedding. If,
however, by using an abundance of bedding and saving all the
high-priced nitrogen and the larger part of the potash in the manure,
he is able to raise twelve tons of silage in place of eight tons, or
three tons of hay in place of two tons, his enterprise as a whole will
be more profitable when he uses the extra amount of bedding, although
so far as the production of a quart of milk is concerned the cost is
increased. It may be that by feeding corn to cattle or sheep one will
obtain only 50 cents a bushel for his maize, while his neighbor is
selling it to the elevator at 60 cents. If, however, the man who feeds
his maize year after year thereby raises 60 bushels instead of 40
bushels, his enterprise, as a whole, may be more profitable than that
of his neighbor.

As a matter of fact, the Pennsylvania experiment station has
substantially these two conditions in certain of its fertilizer plats.
When for 25 years the conditions have been similar to those where
crops are sold from the farm, the yields have been: Maize, 42 bushels;
oats, 32 bushels; wheat, 14 bushels; and hay, 2,783 pounds per acre.
But when conditions exist which represent the feeding of corn, oats
and hay and the return of manure to the soil, the yields have been:
Maize, 58 bushels; oats, 41 bushels; wheat, 23 bushels; and hay 4,190
pounds per acre. In the first instance the value of the products has
been $15.75 an acre, while in the other case it has been $22.90 an
acre.

Having worked out a cropping system that gives the proper yearly
production of several crops desired, the next question to decide is
how this cropping system and the disposition of the crops is going to
affect the fertility of the soil. From a financial or economic point
of view the most important soil element is nitrogen. First, because it
costs from 18 to 20 cents a pound, while phosphoric acid can be
purchased at five cents, potash at four cents; an