ps.

3. The so-called "complete" fertilizer that supplies some nitrogen
with the two other plant-constituents. Such fertilizer should
furnish, with few exceptions, 3 per cent of nitrogen, if no more.

Amount of Application.--In common practice fertilizers are not applied
freely enough when they are used at all. The exception to this rule may
be found in the case of small applications to cold and inert soils to
force growth in the first few weeks of a plant's life. It is difficult
to see how 80 or 100 pounds of fertilizer can affect an acre of land
one way or the other, but experience teaches that such an amount can do
so in respect to young plants. Phosphoric acid has peculiar power in
forcing some development of roots in a small plant, and a small
application in the drill or row may help the plants to gain ability to
forage for themselves.

In early spring a small application of nitrate of soda has marked
effect, tiding the plants over a period of need until the soil is ready
to give up a part of its store.

If a soil is not fertile, and fertilizers are needed as an important
source of plant-food throughout the season, the application should be
liberal. If it is necessary to plant a field that is deficient in
fertility, expending labor and money for tillage and seed, the only
rational course is to furnish all needed plant-food for a good yield.
There may be little net profit from the one crop, but there will be
more than could be obtained without the liberal fertilization, and the
soil will be better equipped for another crop. This applies, in a
notable degree, to fertilization of a wheat crop with which timothy and
clover will be seeded. The difference in cost of 350 pounds of a
high-grade fertilizer and 150 pounds of a low-grade one, when applied
to a poor soil under these circumstances, may be recovered in the grain
crop, and at the same time a good sod will be made possible for the
permanent improvement of the land. It is a safe business rule that land
should be left uncultivated unless enough plant-food can be provided in
some way for a good yield. The man who cannot incur a heavy fertilizer
bill, when necessary, should restrict acreage for his own sake.

Similarity of Requirements.--Many of our staple crops are very similar
in their fertilizer requirements, and this simplifies fertilization.
Setting aside the impression gained from the dissimilarity in the
so-called corn, potato, wheat, and grass