No. 6. 



DEPARTMENT OF AGRICULTURE. 

 PLANT FOOD PER ANIMAL PER YEAR. 



3<5 



The preceding figures are, of course, averages and different sam- 

 ples of farm manure may vary quite widely, depending first, on the 

 kind and amount of food consumed, second, on the kind of animal, 

 and last, but not least, ou the care of the manure. 



Since all of the fertilizing value of the manure is derived from 

 the food, and since the Aarious cattle foods differ widely in the 

 amounts of plant food they contain, the resulting manure is quite 

 variable. Straw and poor hay are among the materials lowest in 

 plant food, often containing hardly a dollar's worth per ton, while 

 the grains are much richer, and some of the by-products, as cotton- 

 seed, linseed and gluten meals, contain very large quantities of 

 fertilizing material, often almost equal in value to their selling 

 price. The nitrogen varies most widely, being almost lacking in 

 ripe straw and rising in cottonseed meal to more than six per cent.; 

 the grasses and corn are poor in nitrogen, while all legumes, such as 

 clover, pea, beau, etc., are rich in this element. 



The value of the manure also depends on the kind of animal that 

 produces it. A full-grown ox at rest in the stall returns in the 

 manure pile all of the nitrogen, phosphoric acid and potash con- 

 tained in the food, i. e. the fertilizing values of the food and of the 

 manure are equal. A steer in the last stage of fattening passes on 

 to the manure pile nearly all of the fertilizing value of his food, 

 for he has built up the frame work of his body, and is merely filling 

 out the structure with fat. Fat contains no nitrogen, phosphoric 

 acid or potash, and consecjuently no matter how much fat he puts 

 ou his body, he is not robbing the manure of its plant food. 



On the other hand the young, growing animal is building up the 

 bones of the body that are formed from the phosphoric acid of the 

 food, while much nitrogen is needed for the formation of muscle, 

 tendons, skin, hair, horn, hoof, blood, and all the organs and fluids 

 of the body. The cow also abstracts much fertilizing value from 

 her food to produce tlie casein and albumen of the milk, both of 

 which {ire rich in nitrogen and phosphoric acid. 



