1913.1 



PUBLIC DOCUMENT — No. 31. 



31 



Manure alone compared with Manure and Sulfate of 



Potash. 



South Corn Acre. 

 The two systems of manuring have been under comparison 

 for twentj-two years. The field consists of four plots of one- 

 fourth acre each. Two of the plots — 1 and 3 — receive an 

 application of barnyard manure at the rate of G cords per acre, 

 while the other two receive an application of manure at the 

 rate of 4 cords per acre, and in addition an application of high- 

 grade sulfate of potash at the rate of 160 pounds per acre. 

 The crop grovtm this year was corn. The relative standing of 

 the two systems for this year is shown in the following table : — 



The following table gives the amount of fertilizer used per 

 acre on each plot, its cost and the profit: — 



1 Represents the actual cost of the fertilizer used. 



2 The late spring and the unusually dry summer were not favorable for a good corn crop. In 

 1911 on these same plots the average yield of the four plots was over 86 bushels per acre. 



3 Based on the value of the crop at harvest time. 



< Represents the difference between the cost of the material used and the value of the crop. The 

 cost of spreading the manure was not considered because this item of expense would not be the 

 same in very many cases. 



