tly
ingredient in plant food, and unfortunately it is very easily washed out
of the soil and lost. Perhaps it is absolutely impossible to entirely
prevent all loss from leaching; but it is certainly well worth our while
to understand the subject, and to know exactly what we are doing. In a
new country, where land is cheap, it may be more profitable to raise as
large crops as possible without any regard to the loss of nitric acid.
But this condition of things does not last long, and it very soon
becomes desirable to adopt less wasteful processes.

In Lawes and Gilbert's experiments, there is a great loss of nitric
acid from drainage. In no case has as much nitrogen been obtained in the
increased crop as was applied in the manure. There is always a loss and
probably always will be. But we should do all we can to make this loss
as small as possible, consistent with the production of profitable
crops.

There are many ways of lessening this loss of nitric acid. Our farmers
sow superphosphate with their wheat in the autumn, and this stimulates,
we think, the growth of roots, which ramify in all directions through
the soil. This increased growth of root brings the plant in contact with
a larger feeding surface, and enables it to take up more nitric acid
from its solution in the soil. Such is also the case during the winter
and early spring, when a good deal of water permeates through the
soil. The application of superphosphate, unquestionably in many cases,
prevents much loss of nitric acid. It does this by giving us a much
greater growth of wheat.

I was at Rothamsted in 1879, and witnessed the injurious effect of an
excessive rainfall, in washing out of the soil nitrate of soda and salts
of ammonia, which were sown with the wheat in the autumn. It was an
exceedingly wet season, and the loss of nitrates on all the different
plots was very great. But where the nitrates or salts of ammonia were
sown in the spring, while the crops were growing, the loss was not
nearly so great as when sown in the autumn.

The sight of that wheat field impressed me, as nothing else could, with
the importance of guarding against the loss of available nitrogen from
leaching, and it has changed my practice in two or three important
respects. I realize, as never before, the importance of applying manure
to crops, rather than to the land. I mean by this, that the object of
applying manure is, not simply to make land rich, but to make crops
grow.