supplies of
fertility. The area devoted to such sales will grow greater because
human needs are imperative. Livestock will become more and more a means
of working over the material that man cannot eat--the grass, hay,
stalks, by-products in manufacture, and coarse grains. The demand for
meat and milk will lead to careful conversion of material into this
form of food, and the animals on eastern farms will increase in number
for a time, while sales of grain and vegetables grow greater. The draft
upon soil fertility through sales must increase because every pound of
material sold from the farm carries plant-food in it.

The Value of Manure.--It is not possible to put a commercial valuation
upon farm manures that may be a sure guide to any farmer. The value
depends upon what the individual can get out of it in crops and
improved soil conditions. It is rather idle to say that the annual
product of a horse in the form of manure is $30, or more or less, even
when an analysis shows that the nitrogen, phosphoric acid, and potash
contained in it are worth that sum when valued at the market prices of
those plant constituents. If the total amount of fertility found in the
voidings of all the animals of the farm were provided in a pile of
commercial fertilizer containing the same amount of each plant
constituent, its worth to the farmer would depend upon his ability to
convert all that fertility into crops at a profit. There are farmers so
situated in respect to soils, crops, and markets that they can make a
good profit from an investment of $30 in the total liquid and solid
voidings of a horse for a year. On the other hand, there are many who
would fail. The values usually given are relative and suggestive. They
are aids in forming judgment. Actual value on the farm depends much on
the man.

The Content of Manure.--When the crops of a farm are fed, the manure
contains nearly all the plant-food that went originally into the crops.
In the case of idle work-horses on a maintenance ration, the manure
contains practically all the plant-food. Cows giving milk remove some
fertility, and a growing calf or colt may take out 30 per cent. There
is some waste beyond control, but when manure is made on tight floors
with good bedding, and is drawn to the field fast as made, on the
average it carries back to the soil fully four fifths of the plant-food
that existed in the feed. Disregarding all cash valuations for the
moment, here is an index