266 FARM MANURE 



animal per day and then adding litter, the ammonium car- 

 bonate is changed to ammonium sulphate, thus: 



(NH 4 ) 2 C0 3 + CaS0 4 = (NH 4 ) 2 S04 + CaCOs. 



Ammonium sulphate is non-volatile, although it is soluble, 

 and must be prevented from leaching. The advantage is 

 that no ammonia escapes into the air. Gypsum is perfectly 

 safe to use because it has no harmful effect on the feet of the 

 animals. By itself it has no fertilizing effect on the soil, 

 but after reacting with ammonium carbonate, the resulting 

 calcium carbonate will neutralize soil acids, although there 

 is but little present at any one time. 



2. Acid Phosphate. — This material may be used at the 

 rate of 50 pounds per ton of manure, but on account of its 

 harmful effect on the feet of animals it is better to use it in 

 the gutters or with manure after the latter has been removed 

 from the stalls. The value of acid phosphate is two-fold. 

 It holds the ammonia as ammonium sulphate, due to the 

 calcium sulphate in the fertilizer. And furthermore, it rein- 

 forces the manure with phosphoric acid which is the deficient 

 element. It is stated that acid phosphate is the most 

 efficient holder of ammonia in use. 



3. Potash Salts. — The muriate and sulphate of potash, 

 kainite, or any of the salts of potash used as fertilizers, 

 except potassium carbonate (see below), are used at the 

 rate of 50 pounds per ton of manure. These compounds 

 are also injurious to the feet of animals and should be used 

 like acid phosphate. Ammonia is converted to ammonium 

 chloride or sulphate and is non-volatile, although soluble. 



4. Sulphurous and Sulphuric Acids. — These acids will 

 retain ammonia as the sulphite (later changing to the 

 sulphate) and the sulphate, but they are not to be recom- 

 mended, for their acid character renders them harmful to 

 the soil if they are not completely neutralized. 



5. Preservatives. — To check bacterial action and thus 

 prevent the formation of ammonium carbonate, such pre- 

 servatives or antiseptics as carbon disulphide and soluble 

 fluorides have been employed. Their use, however, should 



