14 



SOIL FERTILITY 



of manure production as a basis and tlie present selling price of 

 the chemical constituents, we have the table as follows: 



Weight and Value of Solid a<nd Liquid Excrement and of Nitrogen, Phos- 

 phoric Acid and Potash Contained Therein. Per Year Animal.* 



Horse 



Cattle . 



Sheep 



Hogs. 



In the last column we learn that the average horse, well fed, 

 will void in a year both liquid and solid manure to the value 

 of above $25.51 ; that the cow voids about $32.58 worth. These 

 figures seem very high and are much higher than most farmers 

 would be able to recover because much manure is dropped by 

 the roadside or on the hillside pasture and washed away. The 

 urine, so rich in nitrogen, is often largely wasted about the 

 farm. Another loss probably as great as all others is the leach- 

 ing, and, in the case of the horse manure, heating in piles. If, 

 therefore, only a half or even a third, of the total amount cal- 

 culated were to be regularly saved the amount still would be an 

 item highly well worth considering, especially when we remember 

 that aside from its chemical, there are the physical and bacterial 

 values. 



QUESTIONS 



1. What three elements of the soil are moat likely to require replacing 



artificially ? What would you consider as the fourth element ? 



2. What are they worth per pound? 



3. What would a ton of clover hay be worth as manure? A ton of timothy? 



4. What substance regularly sold from the farm brings in the most money 



for the soil fertility that is lost? 



5. Explain in what sense butter is made of " wind and water." 



* Ohio Agri. Exp. Sta. Bui. 246, p. 726, 1912. 



