fine, hair-like roots are easily distinguished by the naked eye, and
these nodules are the home of a teeming, microscopical, industrious
population, who perform their allotted work with the silent, persistent
energy so often displayed in Nature. Men of science have been able to
identify at least three classes of these bacteria, and to ascertain the
work accomplished by each. The reason for their existence would seem to
be that one class is able to convert the nitrogen in the air into
ammonia, whilst others work it into nitrite, and the third class so
manipulate it as to form a nitrate which is capable of being used for
plant food.

Now, although one ton of alfalfa removes from the soil 50 lb. of
nitrogen, yet that crop leaves the soil richer in nitrogen, because the
alfalfa has encouraged the multiplication of those factories which
convert some of the thousands of tons of nitrogen floating above the
earth into substance suitable for food for plant life. As a dry fodder
for cattle three tons of alfalfa contains as much nutrition as two tons
of wheat.

The cost of growing alfalfa greatly depends upon the situation of the
land to be dealt with; also upon whether labour is plentiful or not;
but, in order to give some idea of the advantage of growing this cattle
food, we will imagine the intrinsic value of the undeveloped land to be
£4,000, upon which, under existing conditions, it would be possible to
keep 1,000 head of animals, whereas if this same land were under alfalfa
3,000 to 3,500 animals would be fattened thereon, and the land would
have increased in value to £20,000 or £30,000.

Now, if the undeveloped land is to be improved, it becomes necessary
either to work it yourself, with your own men, in which case you must