MANURIAL VALUE OF FEEDING STUFFS 



213 



mercial fertilizers when bought in large quantities, i.e., nitrogen 18, 

 phosphoric acid 4.5, and potash 5 cts. per pound.^ 



Fertilizing constituents recovered in manure.— The animal creates 

 nothing of fertilizing value, for it voids only that which it has eaten 

 or drunk. Part of the nitrogen, phosphoric acid, and potash of the 

 food may be retained in the body during growth or may go into the 

 milk. All the rest is excreted in the urine and feces. The value of 

 the manure therefore depends, first of all, on the kind of feed the ani- 



FiG. 60a. — Such Losses of Fertility Occur on ]\Iany Farms 



When manure is loosely piled under the eaves, heavy losses of fertility occur 

 thru fermentation and leachino:. Note that every hard rain will leach fertility 

 from the manure pile to tlie ditch in tlie foreground. (From Wisconsin Station.) 



mal gets. Only feeds rich in nitrogen, phosphoric acid, and potash 

 make rich manure. 



The proportion of the total fertilizing constituents supplied in the 

 feed which is recovered in the manure depends on the age and kind of 

 animal. Mature horses at work store no nitrogen, phosphoric acid, or 

 potash, but merely repair their body tissues as they are broken down. 

 Hence, they excrete all the fertilizing constituents contained in their 



1 Owing to the European war, prices of some fertilizers are at present much 

 higher than here indicated. 



