e company are interesting; they show
that, on an average, cattle, when placed upon alfalfa lands, improve in
value at the rate of $2.00 per head per month, so it is easy to place a
value on its feeding properties. Thus, we will take a camp under alfalfa
capable of carrying 10,000 head of cattle all the year round, where as
the fattened animals are sold off an equal number is bought to replace
them. Such a camp would bring in a clear profit of $200,000 per annum,
and the property should be worth L175,000 sterling. An animal that has
been kept all its life on rough camp, and, when too old for breeding, is
placed for the first time on alfalfa lands, fattens extremely quickly,
and the meat is tender and in quality compares favourably with any other
beef. No business in Argentina of the same importance has shown such
good returns as cattle breeding, and these results have been chiefly
brought about by the introduction of alfalfa, and a knowledge of the
life history of alfalfa is of the greatest importance to the cattle
farmer. All cereal crops take from the soil mineral matter and nitrogen.
Therefore, after continuous cropping the land becomes exhausted and
generally poorer; experience has taught us that rotation of crops is a
necessity to alleviate the strain on the soil, and such an axiom has
this become that in many cases English landlords insist that their
leases shall contain a clause binding the tenants to grow certain stated
crops in rotation.

This system is known in England as the four-course shift. Knowledge
gained by successive generations of observant farmers has given us the
key to what Nature had hitherto kept to herself, and to-day we know why
the plan adopted by our forefathers was right, and why the rotation of
crops was, and is, a necessity. Men of science are devoting their lives
to the systematic study of Nature's hidden secrets, and by means of
Agricultural Colleges, as well as private individual research, these
discoveries are being given to mankind, and long before the soils of
Argentina show any serious loss of nitrogen from continuous cropping,
science will probably have established means of applying in a practical
manner those methods already known of propagating the
nitrogen-collecting bacteria which thrive on alfalfa, clover, peas, soya
beans, and other leguminous plants. Almost every country is now devoting
time, money, and energy to agricultural research work. In 1908 the
Agricultural College at