610 SOILS: PROPERTIES AND MANAGEMENT 



Acid phosphate, when used as a reinforcing agent, is 

 applied at the rate of 50 pounds to the ton of manure. 

 It is soluble, and therefore becomes intimately mixed 

 with the excrement. It adds phosphorus, in which 

 manure is especially lacking. Its gypsum may react 

 with the ammonia. Theoretically it should prevent loss 

 by fermentation, as well as function as a balancing agent. 

 It must not come into contact with the feet of farm ani- 

 mals. 



Raw rock phosphate, or floats, is a very insoluble com- 

 pound, and consequently reacts but slowly with the 

 soluble constituents of manure. Carrying such a large 

 percentage of phosphorus, it tends to balance the product 

 and to raise its agricultural value. It is supposed that 

 the intimate relationship between the phosphate and the 

 decaying manure increases the availability of the former 

 to plants when the mixture is added to the soil. Xo 

 increased solubility, however, as determined by chemical 

 means, has ever been as definitely shown to occur (see 

 par. 439). The reinforcement is usually at the rate of 

 100 pounds to the ton of manure. 



514. Benefits from reinforcing. — Experimental data 

 have shown that these various reinforcements have no 

 effect on the nature, function, and. number of the bacterial 

 flora. Their conserving influence, if any, when the ma- 

 nure is exposed, must be in checking leaching and in 

 preventing loss of ammonia. The following figures 

 from Ohio experiments ! show how slight this conserving 

 effect is. The reinforcement was at the rate of 40 pounds 

 to the ton : — 



1 Thome, C. E. Maintenance of Fertility. Ohio Agr. 

 Exp. Sta., Bui. 183, p. 206. 1907. 



