MANUAL FOR SUGAR GROWERS. 



49 



nia was added in solution, and a definite quantity of 

 water added. A very shallow dish, the bottom of 

 which was moistened with sulphuric acid, was j)laced 

 above the soil. Any ammonia escaping from the soil 

 would be speedily absorbed by the acid. 



Proceeding in this manner, and using one part of 

 sulphate of ammonia to five hundi'ed of soil, the non- 

 calcareous soil gave off in two days ammonia equal in 

 quantity to .017 per cent, of the sulphate of ammonia 

 employed. The results in the case of the calcare- 

 ous soil are given in tabular form below. 



Per cent, of added ammonia lost in first 2 davs 

 " " next 3 "" 



<< (( ii> ii> (( Q " 



Per cent, of added ammonia lost in 8 days 



500 g r m s. 

 soil and .5 

 grms. s. 

 ammonifi. 



2.84 



500 grms. 

 soil and .2 

 grms. s. 

 ammonia. 



0.90 

 0.60 

 0.41 



1.91 



Now, as in all probability the loss is greater un- 

 der the conditions of the experiment than it would 

 be in the field, it does not seem necessary to aban- 

 don the use of sulphate of ammonia on calcareous 

 soils, provided that they are in faiiiy good condi- 

 tion ; in the case of poor calcareous soils contain- 

 ing but little vegetable matter, the loss would no 

 doubt be much greater than in the above experi- 

 ments. 



The amount of various substances removed from 

 the soil by a cane crop has been most carefully esti- 

 mated by Professor Harrison. (See report of Dodds' 



