en 20 pounds
Phosphoric Acid 70 "
Potash 20 "

This means that cotton roots are fairly strong feeders of nitrogen and
potash, but are weak on the phosphoric acid side.

The small grains, wheat, oats, barley and rye, can use tough
phosphoric acid and potash, but are weak on nitrogen, and as they make
the greater part of their growth in the cool spring before
nitrification is rapid, they are benefitted by the application of
nitrogen, particularly in the form of nitrate, which is quickly
available.

Clover, peas, beans, etc., have the power of drawing nitrogen from the
air, but draw from the soil lime, phosphoric acid and potash. Hence
the phosphates, potash manures and lime are desirable for these crops.

Root and tuber crops are unable to use the insoluble mineral elements
in the soil, hence they require application of all the important plant
foods in readily available form. Nitrogen is especially beneficial to
beets. Turnips are benefitted by liberal applications of soluble
phosphoric acid. White and sweet potatoes require an abundance of
potash.

If we are growing tender, succulent market garden crops, we need
nitrogenous manures, which increase the growth of stem and foliage.

Fruit trees are slow growing plants and do not need quick acting
fertilizers.

The small fruits, being more rapid in growth, require more of the
soluble materials.

A dark, healthy green foliage indicates a good supply of nitrogen,
while a pale yellowish green may indicate a need of nitrogen.

A well developed head of grain, seed pod or fruit indicates liberal
supplies of phosphoric acid and potash.

THE SOIL

Soils that are poor in humus are generally in need of nitrogen.

Heavy soils are generally supplied with potash but lack phosphoric
acid.

Sandy soils are apt to be poor in potash and nitrogen.

SYSTEM OF FARMING

A system of general or diversified farming embracing crop products and
stock raising, requires much less artificial manuring than does a
system which raises special crops or quick growing crops in rapid
succession, as in the case of truck farming or market gardening.

TESTING THE SOIL

Every farmer should be more or less of an investigator and
experimenter.

The factors mentioned previously as indicating the presence or absence
of sufficient quantities of certain plant foods serve as a general
guide, but are not abs