FIBERS, TUBERS, ROOTS 17 



Nearly all forage crops may be included in one of two 

 <2;eneral classes, the grasses and the legumes. The first 

 includes timothy, blue grass, redtop, brome grass, Bermuda 

 grass, Johnson grass, and all similar crops; the legumes 

 include such crops as alfalfa, red clover, white clover, cow- 

 peas, soy beans, Japan clover, and field peas. Most of these 

 are grown ordinarily for forage, either as hay or pasture 

 crops, though a few, such as field peas, cowpeas, soy beans, 

 field beans, and peanuts, may be grown for their seeds. 



Of the nearly 72,000,000 acres in harvested hay and forage 

 crops reported by the Census of 1910, 27.17 per cent was in 

 mixed timothy and clover meadow; 23.45 per cent in wild, 

 salt, or prairie grasses, and 20.4 per cent in timothy alone. 

 Alfalfa occupied 6.54 per cent of this area; clover alone, 3.4 

 per cent; grains cut green for hay, 5.92 per cent; and coarse 

 fodder, such as sorghum and fodder corn, 5.69 per cent. 



9. Fibers. The fiber crops grown in the United States 

 are cotton, flax, and hemp. Of these three, cotton is by far 

 the most important. Its cultivation is confined to the 

 southeastern portion of the country, including Texas and 

 Oklahoma. The cotton crop ranks second in value of all 

 our field crops, being surpassed only by corn, though wheat 

 and hay often almost equal it. Flax is grown principally 

 for grain; its use as fiber is merely incidental. Hemp is pro- 

 duced in a limited way in a few scattered areas. 



10. Tubers. The only important tuber crop is the 

 potato, sometimes locally known as the Irish, or white, 

 potato to distinguish it from the sweet potato, which is a 

 root, not a tuber. This is one of our important food crops, 

 the production in 1917 being 442,536,000 bushels, valued at 

 $543,865,000. It occupies about three fourths of 1 per cent 

 of the area of improved farm land, and ranks sixth in value 

 among our field crops. 



11. Roots. The principal root crop of the United States 

 is the sweet potato, which was grown on 953,000 acres in 



