46 ELEMENTS OF FARM PkACTICE 



is one of the best grain crops to use as a nurse crop for clover, 

 timothy and other grasses. 



Kinds of Wheat. — There are a great many kinds of 

 wheat, but few are commonly cultivated. They are broadly 

 classed as spring and winter wheat. Winter wheat is dis- 

 tinguished as soft, semihard, and hard, and spring wheat 

 as soft, hard, and durum, or macaroni. Spring wheat is 

 seeded in the spring and harvested in late summer. Winter 

 wheat is seeded in the fall, lives over winter, and is harvested 

 in midsummer. From 60 to 70 per cent of the wheat grown 

 in the United States is winter wheat, mostly of the Turkey 

 variety, the standard hard winter wheat. Minnesota and 

 the Dakotas produce about 70 per cent of the spring wheat 



* Figure 17. — ^A fine field of wheat. 



grown in this country, a large part of which is of the fife 

 or bluestem type. 



Soil for Wheat. — Wheat will do well on any ordinarily 

 productive soil in temperate zones having a well-distributed 

 annual rainfall of from 20 to 40 inches. The chief essentials 

 are available plant food and moisture. It does best on land 

 where a cultivated crop like corn or potatoes has preceded 

 it or on land that has been summer fallowed. 



Manures and Fertilizers. — The grain removes from the 

 soil considerable amounts of nitrogen, phosphoric acid, and 

 potash. In 1,000 pounds of wheat there are 19.8 pounds 

 of nitrogen, 8.6 pounds of phosphorus, and 5.3 pounds of 

 potash. As the straw contains about 15 per cent of potash 

 and very small per cents of the other mineral matter, as 



