purple, pea-like flowers which grow in long, loose clusters. On loose, permeable soils, the top root frequently descends ten to twelve feet, and has been said to reach even fifty feet. Al- falfa has been raised with more or less success in different parts of the United States at elevations from sea level to 7000 feet. It grows best on rich, sandy, well-drained loams of a calcareous nature, and does not succeed on damp soils or tenacious clays. It seems cspeciall' adapted to the rich soils of the arid West, where water is supplied chiefly by irrigation. Young alfalfa plants are relatively tender, and two years are required thorough!}' to establish a field; but when once established, the plant endures for many years. In the United States it is seeded: in the North, in spring: in the South, in either September or February; and in California and the Southwest, trom August to the middle of December, and from February to April. Alfalfa is giown for seed to a considerable extent in Ne- braska, Colorado, and Kansas. The crop is cut when the plants are coming into bloom, and again from two to six times, according to the length of the season. The ordinary annual yield varies from three to eight tons of dry hay per acre, and sometimes reaches ten or twelve tons. The crop is seeded either broadcast or in drills, at the rate of fifteen to twenty-five pounds of seed per acre. Alfalfa, like other leguminous plants, takes up nitrogen from the air. It also brings up from the subsoil considerable amounts of potash, phosphoric acid, lime, and other min- eral matters. It is therefore valuable for green manuring. The roots and stublile from an acre contain about twenty pounds of phosphoric acid, thirtv-eight pounds of potash, and ninety pounds of nitrogen.
A variety of alfalfa known as Turkestan alfalfa (Medicago saliva turkestanica) , is the chief forage plant grown in Central Asia and Turkestan for cattle. It has been widely tested in the United States. In the States west of the Mississippi River and north of Kansas and California, it seems to endure drought better, is not so easily afi'ected by freezing, and gives better results on strong, alkali .soils than the alfalfa commonly grown (Mcdicoflu satira). Two other forms of alfalfa, sometimes cultivated, are the intermediate alfalfa (Medicago media), and the yellow or sand lucerne {Medicago falcata). the seed of which are sometimes used to adulterate that of Medicago sativa. These varieties are not so valuable as the true alfalfa.
Feeding Value. Alfalfa is used as a soiling crop, as pasturage, aiid in the form of silage and hay. Green or cured as hay, it is relished by all farm animals. It may be used either for fattening stock or for milk production. The green product has the following percentage com- position: water, 71.8; protein, 4.8; ether e.v- tract, 1; nitrogen free extract, 12. .S; crude fibre, 7.4; and ash, 2.7. When cured as hay, alfalfa has the following percentage composition: water, 8.4; protein, 14.3: fat, 2.2; nitrogen free extract, 42.7: crude fibre, 25, and ash, 7.4. Like other leguminous crops, alfalfa is compar- atively rich in nitrogen. The difl'erent crops and cuttings do not vary greatly in composition. When alfalfa flowers begin to appear, the stalk' constitutes about 50 or 60 per cent., and the leaves 40 or 50 per cent, of the whole plant. At the usual time of cutting, alfalfa leaves con- tain one-third more of the total dry matter of the crop. The leaves contain one-quarter to one-third as much crude fibre as the stalks, and two or three times as much albuminoids. As shown bj' experiments with cattle, the following percentage amounts of the ingredients are usual- ly digested: 60.7 per cent, of the total organic matter, 72 per cent, of ihe protein, and 69.2 per cent of the nitrogen free extract. Of the crude fibre of alfalfa hay, about 40 per cent, is on an average digestible. Chemical analysis and diges- tion experiments show that alfalfa compares very favorably with red clover, both as green fodder and as hay. When fed as a soiling crop, it should be partially wilted or mixed with hay or straw. In dry regions of the West it is much used for pasturage, especially in the fall. But there is always more or less danger of its causing the cattle to bloat or of the plants being killed by too close pasturage. Alfalfa has proved a sat- isfactory green crop for pigs. It is as hay that alfalfa finds perhaps its most extended use. Cattle, sheep, and horses seem to thrive on it. To secure a well-balanced and economical ration, alfalfa hay, which contains a fairly large pro- portion of protein, should be fed with corn, wheat, oat straw, root crops, etc., which contain comparatively large amounts of carbohydrates and fat. In many instances farmers might profitably raise alfalfa as a substitute for the wheat-bran, cottonseed meal, and other materials containing large amounts of protein, which they now buy in order to utilize by combination, in the form of well-balanced rations, the excess of carbohydrates produced in corn and other crops.
Alfalfa Diseases. The principal diseases to whieli alfalfa is subject are a leaf spot and a root-rot. The leaf spot, due to the fungus Pseu- dopeziza medicaginis, is found in nearly every locality where alfalfa is grown. Sometimes seedling plants are attacked, but usually the fungus occurs on the leaves of older plants. It may be recognized by the occurrence of minute brown spots of irregular shape upon the green or discolored leaflets. The disease readily sur- vives the winter, and in severe attacks to pre- ent spreading the plants should be covered with straw and burned. The root-rot is caused by a fungus, Ozonium auricomiim, which attacks the plants at the crown, following the root down- ward for some distance, and ultimately killing the plant. The disease spreads in the" field, in almost perfect circles, and sometimes causes, in a single season, bare places fifty feet or more in diameter. Alfalfa is also attacked by a para- sitic flowering plant known as dodder (q.v. ).
BiCLioGRAPHY. J. G. Smith, "Alfalfa, or Lu- cerne," United Slates Department of Agricul- ture, Farmers' Bulletin, 31 (Washington, 1896); Colorado Experiment Station Bulletin, 35; Kansas Experiment Station Bulletin, So; Wy- oming Experiment Station Bulletin, 33; Utah Experiment Station Bulletin, 31; New Jersey Experiment Station Bulletin, IJ/S. See also bibliography of Alkali Soil.
AL-FARABI, •il'fiirii'be, Abu Nasb Mohammed IBN Taekiian ibn Uzladj al-Fakabi (?-950 A.D.). One of the earliest of Arabian philosophers, who lived in the tenth century. His family was Turkish. He was born in Farab, but proceeded to Bagdad, where he devoted himself to the study of medicine, mathematics, and philosophy. From Bagdad lie went to Haleb (Aleppo), where, except for his close relations to the Saif ed Daula, the ruler of the place, he
