this ancient and perfect order. He has to strip the living mantle
from the earth, replacing it with growth of those species which serve
his needs. Those plants which are most serviceable--which are, indeed,
indispensable in the higher civilization, the grains--require for
their cultivation that the earth be stripped bare and deeply stirred
during the rainy season, and thus subjected to the most destructive
effect of the rainfall. The result is, that in almost all grain fields
the rate of soil destruction vastly surpasses that at which the
accumulation is being made. We may say, indeed, that, except in
alluvial plains, where the soil grows by flood-made additions to its
upper surface, no field tilled in grain can without exceeding care
remain usable for a century. Even though the agriculturist returns to
the earth all the chemical substances which he takes away in his
crops, the loss of the soil by the washing away of its substance to
the stream will inevitably reduce the region to sterility.

It is not fanciful to say that the greatest misfortune which in a
large way man has had to meet in his agriculture arises from this
peculiar stress which grain crops put upon the soil. If these grains
grew upon perennial plants, in the manner of our larger fruits, the
problem of man's relation to the soil would be much simpler than it is
at present. He might then manage to till the earth without bringing
upon it the inevitable destruction which he now inflicts. As it is, he
should recognise that his needs imperil this ancient and precious
element in the earth's structure, and he should endeavour in every
possible way to minimize the damage which he brings about. This result
he may accomplish in certain simple ways.

First, as regards the fertility of the soil, as distinguished from the
thickness of the coating, it may be said that modern discoveries
enable us to see the ways whereby we may for an indefinite period
avoid the debasement of our great heritage, the food-giving earth. We
now know in various parts of the world extensive and practically
inexhaustible deposits, whence may be obtained the phosphates,
potash, soda, etc., which we take from the soil in our crops. We also
have learned ways in which the materials contained in our sewage may
be kept from the sea and restored to the fields. In fact, the recent
developments of agriculture have made it not only easy, but in most
cases profitable, to avoid this waste of materials