56 CROP GROWING AND CROP FEEDING 



suming 27 pounds of dry matter per day, would produce about 20 tons of 

 manure a year. A sheep will produce about three-fourths of a ton of manure 

 yearly, and a pig from two to three tons. The following table gives the 

 analysis of the various manures and their value per ton: 



These figures will not represent the value of ordinary manure allowed to 

 leach away its value under the eaves, but of manure from highly fed animals, 

 carefully preserved, liquid and solid, and protected from rain and firing. 

 The urine is the most valuablQ part of the excrement of animals. The solid 

 manure contains the undigested part of the food, and matter that is in a more 

 or less insoluble state, while the urine contains the matters that have been 

 fully digested and which are in a soluble condition. The composition of the 

 urine, like that of the solid portion, varies with the age of the animals and 

 the quality of the food consumed. There is a far higher percentage of nitro- 

 gen in the urine and less phosphoric acid. In fact, the urine of horses and 

 cattle contains hardly any at all. But it abounds in potash and soda. It is 

 always best to use it mixed with the solid manure, which contains phosphates. 

 Water that has leached from a pile of mixed manure is always a better fertil- 

 izer than urine alone, as it has taken up the phosphates with the other con- 

 stituents. As we have said, the composition of the manure depends largely 

 on the kind of food used. If. the food is of a nitrogenous nature and is easily 

 digested, the nitrogen in the urine will greatly predominate ; but if the food 

 is imperfectly digested, the larger percentage may be in the solid dung. A 

 horse fed on poor hay will show more nitrogen in the dung than in the urine. 

 But a small portion of the nitrogen, phosphoric acid and potash supplied in 

 the food is assimilated and retained in the animal body. Hence the value 

 of the manure depends very largely on the nitrogen content of the food and 

 its richness in the other forms of plant food. With animals which have com- 

 pleted their growth and made their bony skeleton, and which are simply hold- 

 ing their own as regards weight, neither losing nor gaining, the manurial con- 

 stituents of the food are practically all returned in the manure. Figuring 



