BULLETII!^ ]::iro. 204. 



DEPARTMENT OF CHEMISTRY. 



THIRTY YEARS' EXPERIENCE WITH SULFATE 

 OF AMMONIA. 



BY F. W. MORSE. 



Sulfate of ammonia has been used for many j'ears at the Massachusetts 

 Agricultural Experiment Station in field experiments with fertilizers. 

 Sometimes the effects have been excellent and at other times positive 

 injury to crops has apparently been caused by its use. The object of 

 this bulletin is to show the conditions under which sulfate of ammonia 

 has been used, and to point out the way that seems likely to give favorable 

 results when it is applied as a fertilizer. No attempt is made to show its 

 effect in comparison with the other nitrogenous fertilizers used on ad- 

 jacent plots in the same field. The comparative results have been 

 reported from year to year in the publications of the Experiment Station, 

 and nitrate of soda has been superior to the sulfate of ammonia in crop 

 production per unit of nitrogen. 



In determining the significance of the data herein presented, the 

 following suggestions may be of value : — 



1. Sulfate of ammonia as a source of nitrogen was used year after year 

 in a single arbitrary quantity. It is fair to assume that had the appli- 

 cation been varied in amount, as indicated by the probable need of 

 nitrogen of the crop to be grown, better average results would have been 

 secured. Present averages include years in which sulfate of ammonia 

 could not have been expected to bring marked response. 



2. It is possible, and in fact probable, that to depend on a single source 

 of nitrogen is unsound fertilizer practice. What would have happened 

 had the sulfate of ammonia been combined with other sources of nitrogen 

 is of course a ciuestion. 



3. The amount of fertilizer nitrogen applied as sulfate of ammonia was 

 in no way dictated by the value of the crop to be grown. This being the 

 case, any computation as to the profits derived from the use of this 

 material is absolutely meaningless. It was not applied on any profit- 

 making basis. 



