LUCERNE, PURPLE MEDIC K or ALFALFA, known botanically as Medi cago sativa, a plant of the family Leguminosae. In Eng land it is still commonly called "lucerne," but in America "al falfa," an Arabic term ("the best fodder"), which, owing to its increasing cultivation in the western hemisphere, has come into widening usage since the introduction of the plant by the Span iards. M. sativa is now generally recognized to be made up of many strains, varieties or even subspecies. Some of the hardy American strains, such as grimm, may be due to a cross at some time with the hardy yellow-flowered alfalfa (Medicago falcata). It is an erect perennial herb with a branched hollow stem I to 2 ft. high, trifoliolate leaves, short dense racemes of small yellow, blue or purple flowers, and downy pods coiled two or three times in a loose spiral. It has a characteristic long tap-root, often extending 15 ft. or more into the soil. It is a native of the eastern Mediterranean region, but was introduced into Italy in the 1st century A.D., and has become more widely naturalized in Europe ; it occurs wild in hedges and fields in Britain, where it was first cultivated about 165o. It seems to have been taken from Spain to Mexico and South America in the i6th century, but the extension of its culti vation in the Western States of the American Union practically dates from the middle of the i9th century, and in Argentina and the British Dominions its development as a staple crop is more recent. It is much cultivated as a forage crop in France and other parts of the continent of Europe, but has not come into such general use in Britain. It succeeds well in the south of England. Its thick tap-roots penetrate very deeply into the soil; and, if a good cover is once obtained, the plants will yield abundant cut tings of herbage for eight or ten years, provided they are properly top-dressed and kept free from perennial weeds. The time to cut it is, as with clover and sainfoin, when it is in very early flower.
The plant requires a well-drained soil (deep and permeable as possible), rich in lime and reasonably free from weeds.
Lucerne is grown to an enormous extent in some countries to which it appears to be particularly adapted. For example, it was indicated in 1925, in a report published by the British Depart ment of Overseas Trade, that lucerne in Argentina occupied ap proximately 37% of the cultivated area, wheat occupying but 29%, and all grains 58%. In 1923-24 the area of lucerne in Argentina was put at 19,290,000 acres. In the United States in 1919 lucerne grown for hay covered 8,629,00o ac., an area which had increased in 1927 to 11,400,000 acres. In Canada the area of lucerne increased from 56,818 ac. in 1910 to 473,507 ac. in 1924. For many years the French have devoted about 2,500,00o ac. to this crop. Lucerne is not distinguished separately in the agricultural statistics of all countries, but is included generally under forage crops; it is, however, grown in most countries of Europe. In 1927-28 the Danes and Germans appeared to be devoting special attention to increasing the area devoted to lucerne. It is somewhat remarkable that only a comparatively small area of this valuable crop is grown in England and Wales, the total of 44,200 ac. being lower than that of the previous 20 years and only about two-thirds that of "Alfalfa meal," chiefly from the United States, is valuable for poultry food; the consumption in Great Britain is estimated at between i,000 tons and 1,500 tons per annum.