59 



cester, Freetown, Concord, Sunderland (north half), and Amherst 

 (north acre). The average effect per acre of this element is as 

 follows: hard corn, from .3 to 11.2 bushels increase; stover, from 

 406 pounds decrease to 1114 pounds increase. 



Comparative Effect of Potash. Nitrogen and Phosphoric Acid upon 

 Production of Grain and Stover : As last year, our figures afford 

 interesting data bearing upon the relative influence upon grain and 

 stover production respectively of these ingredients of the fertilizers 

 used. The grand average increase in hard corn and stover per acre 

 taking all our experiments into account is as follows : 

 For potash. hard corn, 11 .3 bushels ; stover, 1308 powids. 



Fornitrogen, " " 4.7 " " 389 '• 



For phosphoric acid, " "• 3.6 '' '' 162 *' 



The increase due to potash, then, exceeded that due to nitrogen as 

 folloius: hard corn, 2.40 times; stover, 3.37 times. Over phos2)Jioric 

 acid the average increase was respectively: hard corn, 3.14 times; 

 stover, 8.08 times. As I wrote last year : " 7i thus becomes evident 

 that potash produces relatively more effect xipon the yield of stover than 

 upon that of grain; and that it greatly exceeds either nitrogen or potash 

 in this respect. Next to potash in its effect upon stover ranks nitrogen.'''* 



CONCLUSIONS. 



1. Our results show that soils differ widely in their requirements. 



2. Potash, however, much more often proves beneficial or proves 

 much more largely beneficial than either nitrogen or p)hosphoric acid. 



3. Potash as a rule most largely increases the yield of both grain 

 and stover ; but its effect upon stover production is greater than upon 

 grain production. 



4. Barn-yard manures are, as a rule, relatively deficient in potash, 

 probably because of the loss of a large proportion of the tirine which 

 contains about four-fifths of the total potash of the excretions. 



5. The relative deficiency of many of our soils in potash may, I 

 think, be largely accounted for from the following facts : — 



a. Manures as a rule lack this ingredient, as just j^ointed out. 



b. Farmers who have used commercial fertilizers have, as a rule, 

 bought phosphates or fertilizers rich in phosphoric acid and containing 

 little or no potash. 



♦For comparison see Bulletin No. 9, page 47 



