EXPERIMENT STATION BULLETINS. 



289 



Manure from the sheep barn will be considerably richer than either 

 of the above. 



If well worked into and through the soil, these manures would prob- 

 ably give one-third and possibly more than one-third of the above con- 

 stituents to the crop of the first year, 



Eemembering that the soil, if well managed, must always be able to 

 furnish considerable quantities of the required plant foods, one may, 

 with the above figures, estimate for himself what should be reasonable 

 applications of barn yard manures. 



COMMERCIAL FERTILIZERS. 



The use of commercial fertilizers is much resorted to in the east 

 and to some extent in Michigan. The amounts applied seem extrav- 

 agant in many cases; for frequently they are equal to and sometimes 

 exceed the quantities actually removed from the soil by the crop. This 

 is seldom true in the application of nitrogen, but it is true in the case 

 of phosphoric acid and potash. The following table contains some 

 classified information which may be helpful. 



37 



