174 



These figures probably fairly represent the actual fertilising value 

 of the carefully preserved m inure (both solid and liquid) of well fed 

 and cared for animals. In all c ises the manure was protected f ro:n 

 leachiug and in some cises treated with a smill amount of gypsum as 

 a preservative. "It will be noticed that the average amount of nitro- 

 gen recovered in all the mmure is considerably more than that of the 

 potash and about twice the amount of phosphoric acid." 



In general practice the manure from the different kinds of animals 

 is frequently collected in a common heap until needed. While it is 

 difficult to state an average, mixed barnyard manure properly cared for 

 may be safely assumed to vary in composition within the following limits : 



Per cent. 



Nitrogen varies from ... ... 4 to 0.75 



Phosphoric acid varies from ... ... 2 to 0.40 



Potash varies from ... ... 0.4 to 0.75 



Water varies from ... ... 70 to 80 



COMPARATIVE VALUE OF SOLID AND LIQUID PARTS. 



It is a fact often lost sight of in practice that the urine of animals is- 

 by far the mo3t valuable part of the excreta. The solid excreta con- 

 tains, principally, the fertilising constituents of the food which have 

 failed to be digested or absorbed into the animal system and are, there- 

 fore, chiefly in insoluble forms. The urine, on the other hand, contains 

 those fertilising constituents which have been digested and are largely 

 soluble. The composition of the urine, like that of the solid excreta, 

 varies with the kind and age of the animal, but especially with the 

 nature of food, water drunk, etc., as will be explained later. The com- 

 position of the urine of different kinds of farm animals has been found 

 by analysis to be as follows : 



Chemical composition of the urine of different animals. 





Water. 



Nitrogen. 



Phosphoric 

 Acid 



Alkali ;s. 





Per cent. 



Per cent. 



Per cent. 



Per cent. 



Sheep 



86.5 



1.4 



0.050 



2.0 



Swine 



97.5 



0.3 



125 



2 



Horses 



89.0 



1.2 





1.5 



Cows 



92.0 



0.8 





1.4 



The urine of farm animals may be said to be free from phosphoric 

 acid except in case of sheep and swine, where it occurs in minute traces, 

 but is rich in nitrogen and the alkalies (including potash and soda); 

 consequently it is an incomplete manure and should be supplemented 

 by phosphate if used alone. It is best, however, to app'y it along with 

 the solid excrement, which contains a considerable amount of phos- 

 phoric acid. This latter fact helps to explain why leachings from 

 rotted manure are more valuable as a fertiliser than urine alone. The 

 leachings contain in addition to the constituents of the urine the solu- 

 ble constituents of the solid manure, among which is a considerable 

 amount of phosphoric acid. 



The comparative value of the solid and liquid excrement is shown in 

 the following table : 



