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Ka)isas Academij of Science. 



elements carbon and nitrogen have disappeared from the cul- 

 tivated soils to the largest extent. These cultivated soils have 

 lost from 1200 to 1800 pounds of nitrogen and from 32,400 to 

 to 49,600 pounds of organic matter per acre in the surface 

 soil. On percentage basis, this amounts to from 22.6 to 43.5 

 per cent of the nitrogen, and from 23.3 to 51.3 per cent of the 

 organic matter. It means that these soils have lost, in round 

 numbers, from one-fifth to two-fifths of the nitrogen and from 

 nearly one-fourth to one-half of the organic matter. 



3. Decay of organic matter is the life of the soil. A com- 

 parison between the ratio of nitrogen and carbon in vegetable 

 matter and in the organic matter of the soil shows the enor- 

 mous amount of vegetable matter it has required to produce 

 the organic matter in the soil. The loss of one-third of this 

 organic matter, together with the accompanying nitrogen loss, 

 is the most important cause of the decreased crop-producing 

 power of the soil. 



TABLE II. 



