USES OF CROPS 19 



United States in 1917 was 235,000 short tons, while that 

 of beet sugar amounted to 765,000 short tons. 



13. Stimulants and Sedatives. The only stimulant or 

 sedative crop which is grown to any extent in the United 

 States is tobacco. This crop was grown on 1,295,000 acres 

 in 1909, or 0.27 per cent of our improved farm lands. The 

 production amounted to 1,055,765,000 pounds, valued at 

 $106,000,000, making it rank seventh in value among our 

 field crops. 



14. Miscellaneous and Medicinal Crops. None of the 

 miscellaneous and medicinal crops is grown on a large scale. 

 Among them may be mentioned broomcorn, hops, the castor 

 bean, mustard, and various kinds of mint. 



15. The Uses of Crops. The principal uses of field crops 

 are to supply food and clothing for humanity, to feed ani- 

 mals, to maintain or to restore the vegetable matter and the 

 fertility of the soil and to prevent the loss of fertility through 

 erosion or other means. The principal food crops of the 

 United States are wheat, corn, rice, potatoes, and sweet 

 potatoes. Other crops which are used to a greater or less 

 extent for human food are oats, barley, rye, buckwheat, the 

 sugar beet, and sugar cane. The use of barley, rye, and 

 oats as human food in the United States has increased 

 enormously since our entrance into the world war in 1917. 

 The plants which supply material for clothing are cotton 

 and flax. Many plants furnish food for man indirectly by 

 being fed to animals, to be transformed into meat, butter, 

 and milk. Corn, oats, barley, rye, and the grasses and clovers 

 are the important food crops for the domestic animals 

 which do useful work for man or furnish him with food. 

 Some crops maintain or add to the fertility of the soil by 

 supplying the vegetable matter necessary for the continu- 

 ance of plant growth. Others, by providing a soil cover 

 which prevents washing, leaching, and other natural losses, 

 help to retain the fertility for the production of useful crops. 



