6 



obvious when you recall that sulfate of ammonia consists of 

 ammonia combined with the strong mineral acid, — sulfuric 

 acid. When the ammonia has been nitrified or changed to 

 nitric acid in the soil, still another mineral acid is produced; 

 and when this nitric acid has been finally removed and utilized 

 by the plants, most of the sulfuric acid remains behind as a 

 residual product, just as soda is left as a residual product w^hen 

 nitrate of soda is used repeatedly. 



In connection with my early experiments in Rhode Island I 

 found that reasonable quantities of sulfate of ammonia proved 

 poisonous in one instance the first year instead of acting as an 

 efficient fertilizer; in another part of the State, it did- not 

 become injurious until the second year; and in still another 

 locality, not until the third year. The injury was due to the 

 fact that the soils were fairly to strongly acid at the outset, 

 and their acidity was increased by the sulfate of ammonia to 

 such an extent as to interfere with the proper growth of the 

 plants. 



I recall with much interest having, visited Professor Storer 

 in 1891 or 1892 for the purpose of consulting his library at the 

 Bussey Institution. My object was to make a careful study of 

 all trials of nitrate of soda and sulfate of ammonia which had 

 been made anywhere in the world up to that time. I told 

 Professor Storer of this experience with sulfate of ammonia at 

 the Rhode Island Experiment Station, adding that I appre- 

 hended the difficulty was due to the existing acidity of the 

 soil and that I proposed to apply lime in the effort to correct 

 the condition, in the hope that the sulfate of ammonia w^ould 

 then become an effective fertilizer. In response he warned me 

 that some German investigator had applied lime under some- 

 what similar conditions and that ammonia was liberated. I 

 believed, however, that if proper quantities of lime were used 

 in the right way, there was nothing to be feared in this respect. 

 Upon making the experiment the lime was actually found to 

 work wonders, causing the sulfate of ammonia to become a 

 highly effective fertilizer, better even for some crops than 

 nitrate of soda. 



When organic ammoniates, such as dried blood, fish, or meat, 

 are used, ammonia is first formed from them in the soil, and 



