114 



THE PEOPLE'S FARM AND STOCK CYCLOPEDIA. 



These valuations have been agreed upon for commercial fer- 

 tilizers. As the condition of plant food in barn-yard manures is 

 seldom twice the same, the determination of a standard of valua- 

 tion for them is both difficult and uncertain. A pound of nitro- 

 gen in the manure from highly fed cattle will be worth more 

 than a pound of nitrogen in the manure produced by those 

 which have been poorly fed. An average estimate is therefore 

 the best that can be obtained. In preparing my work, Science 

 in Farming, I adopted the following standards of value, and 

 have not since seen reason for making any change : 



VALUE OP PLANT FOOD IN MIXED MANURE. 



Nitrogen, ........ 



Phosphoric acid, ....... 



Potash, 



VALUE OF PLANT FOOD IN SOLID EXCREMENT. 



Nitrogen, ........ 



Phosphoric acid, ....... 



Potash, 



VALUE OF PLANT FOOD IN URINE. 



Nitrogen, ........ 



Phosphoric acid, ....... 



Potash, 



VALUE OF PLANT FOOD IN FOODS. 



Nitrogen, ........ 



Phosphoric acid, ....... 



Potash 



I give now the following table, taken from Science in Farm- 

 ing, showing the composition of various barn-yard manures, and 

 their values according to the above standard. The calculations 

 are made for one ton of each kind : 



15 cents. 



10 cents. 



6 " 



4 " 



22 cents. 

 12 " 



6 " 



15 cents. 

 8 " 



5 " 



