If soils were composed of nothing but pure silica sand, nothing would ever grow; but in Nature we find that soils contain all sorts of mineral matter, and chief amongst these is lime.

Alfalfa thrives on land which contains lime, and gives but poor results where this ingredient is deficient.  The explanation is simple.  There is a community of interest between the very low microscopic animal life, known as bacteria, and plant life generally.  In every ounce of soil there are millions of these living germs which have their allotted work to do, and they thrive best in soils containing lime.

If one digs up with great care a root of alfalfa (it need not be an old plant, the youngest plant will show the same peculiarity), and care is taken in exposing the root (perhaps the best method is the washing away of the surrounding earth by water), some small nodules attached to the 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 L4,000, 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 L20,000 or L30,000.

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 provide ploughs, horses, bullocks, etc., or to carry out the plan usually adopted, that of letting the land to colonists who have had some experience in this class of work.  Usually a colonist will undertake to cultivate from 500 to 600 acres, and agrees to pay to the landowner anything from 10 per cent. to 30 per cent. of his crops