54 



BOARD OF AGRICULTURE. 



and making a double allowance for an extra crop instead of 

 an average one, about 500 pounds of mineral substances could 

 be removed, of which the three named would compose about 

 375 pounds, and therefore if a restoration was to be effected 

 by means of commercial fertilizers, it would be necessary to 

 employ one in which potash, phosphoric acid, and silica were 

 largely in excess ; but as the latter of the three is plentifully 

 supplied in most soils, it will be necessary to h.ave more re- 

 gard for the two former ; but as it is generally conceded that 

 barn-yard manure is the most natural fertilizer that can be 

 used upon any crop, it is necessary to consider the relative 

 constitution of that material. It is laid down, that in barn- 

 yard manure well rotted and dried, the principal ingredients 

 heretofore named exist in about the proportion of ten per 

 cent. ; so if an estimate of the amount of moisture contained 

 in barn-yard manure can be made, which is known to be ex- 

 ceedingly great, then an approximate basis for a calculation 

 of the relative qualities of the principal manurial substances 

 required will be had ; and having found these, the required 

 amount of manure is easily estimated and therefore applied. 

 But it is seldom that the ordinary farmer feels qualified for 

 the performance of any so difficult task, and hence simply 

 uses his best judgment in the application of his manure, 

 which answers the purpose equally well if his judgment only 

 leads him to make a thorough application. The difficulty in 

 such cases usually consists in a desire to make the most of 

 what is possessed, whereby the same is used upon so large a 

 surface, that notwithstanduig enough is absolutely furnished 

 to restore the waste effected by the growth of the crop, no 

 provision is made for a gradual improvement of the soil, which 

 should be a matter of high consideration and never lost sight 

 of. The corn crop is not as exhaustive to the soil as many 

 others, Avhich also take substances in different combinations ; 

 hence the benefits of a rotation of crops, which should always 

 be so arranged as to require substances that have been least 

 used by the preceding crop, so that while exhaustion is going on 

 in one direction, accumulation is likewise going on in another. 

 Passing to another point, the feeding value of corn and of 



