The figures supplied by one large 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 Ontario prepared no less than 474 packages of Legume Bacteria, and in 309 cases beneficial results followed from the application thereof to the soil; in 165 cases no improvements in the crops were noticed, this may, however, have been due to the want of knowledge of how to manipulate the bacteria, or to lack of experience in noting effects scientifically, but in any case the experiment must be considered successful when the results obtained were satisfactory in no less than 65 per cent. of the trials.  No greater factor exists than the microscope in opening up and hunting out the secrets concealed in the very soil we are standing on.