114 SOILS AND FERTILIZERS 



the crop which removes the largest amount of nitrogen 

 leaves the land in the most impoverished condition. 

 Wheat and many grains, while they do not remove 

 such a large amount of nitrogen in the crop, leave 

 the soil more exhaused than if other crops were grown. 

 This, as will be explained, is caused by the loss of 

 nitrogen from the soil in other ways than through the 

 crop. 37 



Pounds of nitrogen 

 per acre. 



Wheat, 20 bushels 25 



Straw, 2000 pounds 10 



Total .... 35 



Barley, 40 bushels 28 



Straw, 3000 pounds 12 



Total 40 



Oats, 50 bushels 35 



Straw, 3000 pounds ! 15 



Total 50 



Flax, 15 bushels 39 



Straw, 1800 pounds 15 



Total 54 



Potatoes, 150 bushels 40 



Corn, 65 bushels 40 



Stalks, 3000 pounds 35 



Total 75 



126. Nitrates and Nitrites. — The amount of nitro- 

 gen in the form of nitrates and nitrites, varies from 

 mere traces to 150 pounds per acre. Calcium nitrate 



