THE SOIL AND ITS IMPROVEMENT. 115 



The low value of the urine of cattle and swine is largely 

 due to the amount of water they take with their food. 



This table does not show what any particular manure will be 

 worth to the farmer, as that will depend on the soil and crop, 

 but it does show the comparative value. A ton of dried hen 

 manure may not be worth to the farmer $16.41; but if not, 

 then a ton of solid cattle manure will not be worth 86 cents ; 

 and, if the ton of solid manure from cattle is worth more than 86 

 cents, then the ton of dried hen manure will be worth more than 

 $16.41. 



Food and Manure. As we have seen that the value of 

 the manure all comes from the food, and not from the animal, it 

 is often important to know what will be the value of the manure 

 produced from a ton of food. This will depend not only on the 

 food, but on the animal: for, although animals can not add any 

 thing to the manure, yet some take up more of the valuable con- 

 stituents of the food for their own use than others. 



The following table, which is taken from Science in Farm- 

 ing, gives the amount of nitrogen, phosphoric acid, and potash in 

 different foods, and their value according to the standard already 

 given. It differs slightly from the one prepared by Sir J. B. 

 Lawes, which has been so extensively published, as the valu- 

 ation of fertilizers in this country and England is somewhat 

 different. 



In using this table it should be remembered that the manure 

 made from a ton of any of these articles, when fed to fattening 

 animals, will be worth about ten per cent less than the figures 

 here given, and that, when the food is given to young, growing 

 animals, or animals giving milk, the manure will be worth from 

 twenty-five to fifty per cent less than the figures given. It 

 should also be remembered that the estimate thus obtained will 

 be the value of the total amount of manure produced, and the 

 farmer must calculate for himself how much he will allow to 

 be wasted. The plant food in manure produced from foods 

 that are largely digestible will be more soluble, and, there- 

 fore, more promptly available than that in manure made from 

 poor food. 



