8 BULLETIN 923, IT. S. DEPARTMENT OF AGRICULTURE. 



Table 6. — Credit for manure and fertilizing constituents T>y seasons — Continued. 





Winter. 



Summer. 



Item. 



Nitrogen. 



Phos- 

 phoric 

 acid. 



Potash. 



Nitrogen. 



Phos- 

 phori c 

 acid. 



Potash. 



Ma.Tinr« 



Pounds. 



39, 470 



1,145 



Pounds. 



13,005 



397 



Pounds. 



42,102 



2,854 



Pounds. 

 7,587 



Pounds. 

 2,525 



Pounds. 

 8,152 















Total fertilizing constituents 



40,615 



13,402 



44,956 



7,587 



2,525 



8,152 





49.6 



16.4 



54.9 



8.7 



2.9 



9.3 











The average credit allowed for manure and bedding each year in- 

 cludes the manure from the bulls, and represents what was or could 

 easily have been saved under local conditions. Since the total cost of 

 keeping bulls is charged against the cows, the bull manure is included 

 as a direct credit to the herd, and the combined credit was estimated 

 to be 5.3 tons per cow. 



The fertilizing constituents in 1 ton of average manure and bed- 

 ding from the cows during the winter were estimated to be as follows : 



Pounds 

 per ton. 



Nitrogen 10. 8 



Commercial phosphoric acid 3.5 



Potash 11.9 



Without bedding, 1 ton of average winter manure was estimated to 

 contain : 



Pounds 

 per ton. 



Nitrogen 10. 7 



Commercial phosphoric acid 3. 5 



Potash 11. 4 



The fertilizing constituents in the manure and bedding were valued 

 at the following prices a pound during the first year : Nitrogen, 21 

 cents ; commercial phosphoric acid, 6 cents ; and potash, 7 cents ; and 

 during the second }'ear : Xitrogen, 25 cents ; phosphoric acid, 6 cents ; 

 and potash, 7 cents. 



On the average dairy farm the commercial value of manure de- 

 pends upon the use to which it is put. The return in dollars depends 

 upon the increase in the crops raised and the amount received from 

 the sale of these crops. These facts may reduce or increase the value 

 of manure below or above the market price of the fertilizing constitu- 

 ents contained in it. 



REQUIREMENTS FOR KEEPING A BULL. 



The record on one bull for one month, called a bull month, was 

 taken as a working unit. The bulls on about three-fourths of the 

 farms were kept in the barn in the summer. This accounts for the 



