32 



MAIKE STATE COLLEGE 



TABLE XII. 



PLAXT FOOD SUPPLIZD TO THE SEVERAL PLOTS. 





o 











s . 



o 



?x 





!a>c; 



a 1 -c 



P a 



00 1 c 



~ 5 





;z;=. 







Plot 1 

 Plot 2 

 Plot 3 

 Plot i 



1?2 



14 



14 







116 



250 



SO 







176 



50 



50 







Only in the case of the phosphoric acid of Plot 2 do the commer- 

 cial manures exceed or even approach in quantity the plant food 

 furnished by the stable manure. This greater amount of plant food 

 does not fail of its effect, but it is worthy of remark that after three 

 crops have been removed the yield of Plot 1 is inferior to that of 

 Plot 2 and scarcely greater than that of Plot 3. A possible 

 explanation of this is that the soil is especiall}-' lacking in available 

 phosphoric acid and therefore the larger amount of this compound 

 applied to Plot 2 resulted in a more persistent increase of crop. 

 These results so far run counter to the prevailing views as to the 

 relative permanence of effect of animal and commercial manures. 



But the experiment is still in progress and definite conclusions 

 should be withheld for some years. 



The following, however, is a brief summary of the more impor- 

 tant facts to date, as bearing upon the experiment on Field 2 : 



(1) The commercial fertilizers have caused a marked increase 

 of crop for at least four years after their application. 



( 2 ) The fourth crop was larger from the crude phosphate than 

 from the dissolved. 



(4) The first three crops were larger from the yard manure than 

 from the commercial manures but the fourth crop was larger from 

 the latter. 



