SOILS AND FERTILIZERS 



Composition of Dry Matter of Solid and Liquid Manure. 



419 



The distribution of the manurial constituents in the urine and 

 dung depends largely on the nature of the food. If the food is 

 nitrogenous and easily digested the nitrogen in the urine will greatly 

 preponderate ; if, on the other hand, the food is imperfectly digested 

 the nitrogen in the solid excrement may form the larger quantity. 

 When poor hay is given to horses the nitrogen in the solid excre- 

 ment will exceed that contained in the urine. On the other hand, 

 corn, oil cake, and roots yield a large excess of nitrogen in the urine. 



In general, therefore, it may be said that: (1) Of the nitrogen, 

 phosphoric acid, and potash supplied in the lood, comparatively 

 small amounts are assimilated and retained in the animal body, 

 the relation between the amounts of these substances excreted in the 

 urine and the solid excrement depending largely upon the nature 

 of the food. (2) The urine is much richer in nitrogen than the 

 solid dung, usually containing one-half or more of the total amount 

 excreted; it also contains a large proportion of the potash, but is 

 poor in phosphoric acid, which remains almost entirely in the solid 

 excrement. The best results may therefore be expected from apply- 

 ing the mixed solid and liquid excrement. 



Influence of Age and Kind of Animal. The proportions of 

 the potash, phosphoric acid, and nitrogen of the food recovered in 

 the manure vary considerably with the age and kind of animal. 

 Full-grown animals, neither gaining nor losing weight, excrete 

 practically all of the fertilizing constituents consumed in the food. 

 Kapidly growing animals may excrete as little as 50 per cent of the 

 fertilizing constituents of the food; while milch cows excrete from 

 65 to 85 per cent ; and fattening or working animals from 90 to 95 

 per cent. The Mississippi Experiment Station found that young 

 fattening steers excreted on an average 84 per cent of the nitrogen, 

 92 per cent of the potash, and 86 per cent of the phosphoric acid of 

 the food consumed. The Pennsylvania Station reports experiments 

 in which milch cows excreted 83 per cent of the nitrogen, 92 per 

 cent of the potash, and 75 per cent of the phosphoric acid of their 

 food. 



It has been shown that both the amount and the value of man- 

 ure vary to a considerable extent with the kind of animal producing 

 it, the animals producing the smaller amounts as a rule yielding 

 the richer manure. Thus, sheep which produce the smallest amount 

 of manure per 1,000 pounds of live weight rank with hogs in yield- 

 ing that of greatest value per ton, and cows which stand first as re- 



