The roots also put large quantities of humus in the soil. Where crops are regularly grown in short rotations they will suffice to keep it amply supplied for ordinary production. Because of this it is usually considered more profitable to cut both the crops which medium red clover produces in one season, or to pasture off one or both, than to plow under either as green manure. But when soils are too stiff or too open in character it may be advantageous to bury clover to restore the equilibrium. It may also be necessary to bury an occasional crop in order to put the land quickly in a condition to produce some desired crop, the growth of which calls for large supplies of humus. When clover is plowed under it will usually be found more profitable to bury the second growth of the season than the first. The crop is in the best condition for being plowed under when the plants are coming into bloom. If left until the stems lose their succulence the slow decay following in conjunction with the bulkiness of the mass plowed under might prove harmful to the crop following the clover. The influence of the roots upon the mechanical condition of the soil is most beneficial. The roots go down deep into the subsoil and also abound in fibrous growth. The tap roots in their decay furnish openings through which the superfluous water may go down into the subsoil. The fibers adhering to the main roots so ramify through the soil that when even stiff land is filled with them it is rendered friable, and is consequently brought into a good mechanical condition.

While all varieties of clover may be utilized in

producing food and in enriching land, none is equal to the medium red for the two purposes combined. This arises from the fact that none save the medium red grows two crops in one season under ordinary conditions. Though the first crop should be taken for food, as it generally is, there is still ample time for a second crop to grow for plowing under the same season. This second growth is ready for being plowed under when time is less valuable than it would be when the mammoth or alsike varieties would be in season for being thus covered. And yet the work may be done sufficiently early to admit of sowing fall or winter crops on the land which produced the clover.

CHAPTER IV

ALFALFA

Alfalfa (Medicago sativa) previous to its introduction into California, from Chili, about the middle of the last century, was usually known by the French name Lucerne. The name Alfalfa is probably Arabic in its origin, and the term Lucerne has probably been given to it from the Canton Lucerne in Switzerland. It has followed the plant into Spain and South America, and now it seems probable that soon it will be known by no other name over all the United States and Canada. It has also been known by names applied to it from various countries for which it has shown high adaptation, as, for instance, Sicilian Clover, Mexican Clover, Chilian Clover, Brazilian Clover, Styrian Clover and Burgundy Clover. In yet other instances, names have been applied to it indicative of some peculiarity of growth, as, for instance, Branching Clover, Perennial Clover, Stem Clover and Monthly Clover.

Alfalfa is upright and branching in its habit of growth, more so than the common varieties of clover. It usually grows to the height of 2 to 3 feet, but it has been known to reach a much greater height. Although possessed of a single stem when the plants are young, the number of the stems increases up to a certain limit, with the age of the

plants and the number of the cuttings. Forty to fifty stalks frequently grow up from the crown of a single plant where the conditions are quite favorable to growth, and in some instances as many as a hundred. The leaves are not large, but numerous, and in the curing of the plants they drop off much more easily than those of the more valuable of the clovers. The flowers are borne toward the top of the stems and branches, and they are in a long cluster, rather than in a compact head. They are usually of a bluish tint, but the shades of the color vary with the strain from blue to pink and yellow. The seeds are borne in spirally coiled pods. They resemble those of red clover in size, but are less uniform in shape. The color should be a light olive green. The tap roots go down deeply into the soil and subsoil where the conditions as to texture and moisture are favorable. It has been claimed that alfalfa roots have gone down into congenial subsoils 40 to 50 feet, but usually less, probably, than one-fourth of the distances mentioned would measure the depths to which the roots go. And with decreasing porosity in the subsoil, there will be decrease in root penetration until it will reach in some instances not more than 3 to 4 feet. But where the roots are thus hindered from going deeper, they branch out more in their search for food.

Alfalfa is perennial. In the duration of its growth, no fodder plant grown under domestication will equal it. It has been known, it is claimed, to produce profitable crops for half a century. In some of the Western States are meadows from 25 to 40