350 Bacteria in Relation to Country Life 



phosphate, reverted lime phosphate and water-soluble 

 lime phosphate. The latter is the efficient material that 

 unites with the ammonia formed in decay and prevents 

 its escape. Under practical conditions, the use of super- 

 phosphate has not been found to be entirely satisfactory. 



In order to save a large portion of the ammonia it 

 becomes necessary to use considerable quantities of 

 superphosphate so as to render the manure distincth- 

 acid. Stutzer states that Pfeiffer used, in some of his 

 experiments, a low-grade supherposphate at the rate 

 of about one pound for each 1,000 pounds of live weight, 

 and effected a considerable saving of ammonia in the 

 fresh manure. But, after three months of storage, the 

 manure that had received additions of superphosphate 

 had lost more nitrogen than the untreated manure. In 

 the long run, therefore, the application of acid phosphate 

 did not prove of any advantage in the conservation of 

 the manure nitrogen. 



Kainit. — The superphosphate, when it proves effi- 

 cacious at first, owes its conserving power to its acid 

 reaction. The latter enables it not only to unite with 

 the ammonia, but, also, to create conditions unfavor- 

 able to the rapid multipHcation of the bacteria. More or 

 less of the latter effect is also brought about by kainit 

 and other crude potash salts that have been employed 

 in the conservation of manure. When sufficiently large 

 quantities of these salts are used, the bacteria in the 

 manure are hindered in their development, or perhaps 

 entirely suppressed for a time. They act, therefore, 

 in the manner of preservatives, and, by retarding the 

 bacterial activities, they diminish the losses of ammonia. 



