326 THE PRINCIPLES OF SOIL MANAGEMENT 



194. Ammonium sulfate. When coal is distilled, 

 a portion of the nitrogen is liberated as ammonia, and is 

 collected by passing the products of distillation through 

 water in which the ammonia is soluble, forming the 

 ammoniacal liquor. The ammonia thus held is distilled 

 into sulfuric acid with the formation of ammonium 

 sulfate and the removal of impure gases. 



Commercial ammonium sulfate contains about 20 per 

 cent of nitrogen. It is the most concentrated form in 

 which nitrogen can be purchased as a fertilizer, having 

 from sixty to eighty pounds more of nitrogen per ton 

 than sodium nitrate. It is, therefore, economical to 

 handle. Its effect upon crops is not so rapid as that of 

 sodium nitrate, but it is not so quickly carried from the 

 soil by drainage water, as the ammonium salts are 

 readily absorbed by the soil. A pound of nitrogen in the 

 form of sulfate has about the same value as the same 

 amount in the form of nitrate. 



The long and extensive use of ammonium sulfate on 

 a soil has a tendency to produce an acid condition, 

 through the accumulation of sulfates which are not 

 largely taken up by plants. 



Ammonium sulfate, like sodium nitrate, should 

 not be applied in the autumn, as the ammonia is con- 

 verted into nitrates and leached from the soil in sufficient 

 quantities to entail a very decided loss of nitrogen. 

 There is not likely to be so large a loss of nitrogen from 

 ammonium salts as from nitrates, and, as would naturally 

 be expected, there is greater loss of nitrogen when these 

 salts are used alone than when they are combined with 

 other fertilizing ingredients. 



