CONSERVATION OF FERTILITY 25 1 



Exclusive Grain Farming. 

 Sold from the Farm 



Phosphoric 

 Nitrogen. acid. Potash. 



Pounds. Pounds. Pounds. 



Flax, 40 acres 1600 600 800 



Flax straw 600 120 320 



Wheat, 50 acres 1250 625 350 



Wheat straw 500 375 1400 



Oats, 20 acres 700 240 200 



Oat straw 300 1 20 700 



Barley, 50 acres 1400 750 400 



Barley straw 600 250 1500 



Total 6950 3080 5670 



In addition to the nitrogen removed in the crops 

 other losses must be considered. Experiments have 

 shown that when exclusive grain farming is practiced, 

 for every pound of nitrogen removed in the crop, four 

 pounds are lost from the soil in other ways. This 

 would make the total loss of nitrogen over 28,500 

 pounds or 177 pounds per acre, which large as it may- 

 seem is the actual loss from the soil when grain only 

 is raised and sold. Experiments at the Minnesota 

 Experiment Station have shown that after a soil had 

 been cultivated 40 years, the annual loss per acre of 

 nitrogen in exclusive wheat raising was 25 pounds 

 through the crop and 146 pounds due to the oxidation 

 of the nitrogenous humus of the soil. 17 



When exclusive grain farming is followed, the 

 annual losses of fertility from a farm of 160 acres are 

 28,500 pounds of nitrogen, 3000 pounds of phosphoric 

 acid, and 5500 pounds of potash. 



