CHAPTER XII. 



LEGUMINOUS PLANTS FOK GKEEN FOKAGE AND HAY. 



The cereal grain plants corn, wheat, oats, barley, etc. and the 

 grasses timothy, red top, etc. serve mainly for furnishing carbo- 

 hydrates for the nourishment of animals. The legumes alfalfa, 

 clover, vetch, soybean, cowpea, etc. comprise the great group of 

 food-bearing plants characterized by their high nitrogenous or crude 

 protein content. While the first named group primarily furnishes 

 the animal with energy and fat, the last group serves especially for 

 building all the muscular tissues and all the various organs of the 

 body, as well as a part of the skeleton. 



Heretofore we have ascribed the great usefulness of the legumes 

 in nourishing farm animals to their high content of crude protein. 

 We must now give to these plants another value that of furnishing 

 an abundance of lime to animals. Farm animals need a large supply 

 of lime for building the skeleton and replacing the lime which is used 

 up in the metabolic processes or changes which are constantly going 

 on within the body. Pregnant animals store much lime in the skele- 

 ton of the fetus, and animals giving milk undergo a steady loss of 

 lime. Each 100 Ibs. of milk the cow produces carries off 0.75 Ib. 

 of mineral matter, a considerable portion of which is lime. 



Many of the concentrates, such as corn, wheat, bran, middlings, 

 gluten meal, etc., and the roughages, such as corn stover, corn silage, 

 hay, straw, etc., range from poor to fair in their content of lime. Of 

 all the plants widely grown by the farmer, the legumes are, as a 

 class, richest in crude protein and lime. When to these vitally im- 

 portant facts we add the great basic one, that the generous and con- 

 tinuous growing of legumes is absolutely essential to the economical 

 maintenance of soil fertility, then, and only then, do we begin to 

 appreciate the importance of this beneficent group of plants in hus- 

 bandry. (89, Appendix, Table V) 



I. ALFALFA. 



243. Alfalfa, Medicago sativa. The alfalfa plant is at its best in 

 the great semi-arid plains region covering the western half of the 

 United States, where the alkaline soil is usually rich and deep, 

 with perfect drainage. On such land, amply watered by irrigation 



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