120 



Agricultural Chemistry. 



with the daily consumption for a cow weighing 1,000 pounds and 

 giving 15 pounds of milk; 10 pounds of a mixture of one-third 

 each of corn meal, ground oats and bran; 35 pounds of corn 

 silage; 15 pounds of clover hay (medium red). This is a good 

 practical ration and conforms well with the best feeding stand- 

 ards. It will be assumed that just the amount of wheat straw 

 which would theoretically be necessary to absorb the liquid excre- 

 ment is used as bedding. Allowance for milk production is of 

 course made by using the factor of 80 per cent as the basis for 

 calculating the amounts of fertilizing material recovered in the 

 excrement from the total contained in the feeds. 



Fertilizing Constituents of the Manure. 



The prices paid for fertilizing materials at the present time 

 are 15 cents per pound for nitrogen and 5 cents each for phos- 

 phoric acid and potash. These prices hold only when raw ma- 

 terials are bought, and much higher prices are paid for mixed 

 fertilizers. From these prices is calculated the total value of 

 the manure produced by 50 cows in one year : 



Value of Manure for Fifty Cows. 



Value of nitrogen $145;) . 1 s 



Value of phosphoric acid 191 .19 



Value of potash 447.85 



Total value of manure $2094 2 



This means that the fresh manure from 50 cows contains 

 amounts of nitrogen, phosphoric acid and potash that would cost 

 the farmer at least $2094.22 if purchased in commercial fertil- 



