AGRICULTURAL EXPERIMENT STATION. 



31 



In this instance the fertilizers were applied in 1800 and at the 

 end of the season of 1S94 five crops of grain had been removed 

 without an}^ further manuring, but even after the growth of three 

 previous crops the one of 1894 shows in a marked manner the 

 influence of the fertilizers used in 1890. It is too early however, 

 to reach any conclusion as to whether commercial fertilizers can 

 be depended upon as a source of fertility for all time. 



This experiment has already furnished a bit of not insignificant 

 testimony on the use of raw ground mineral phosphates, for grain 

 growing at least. Plots two and three were treated exactly alike 

 excepting that the phosphoric acid applied to plot three was chiefly 

 in the soluble and reverted form, while on plot two it was used in 

 much larger quantities almost wholly in the insoluble form. In 

 other words, an acid or soluble phosphate was used on plot three 

 and a crude ground phosphate on plot two. 



TABLE XI. 



IXGKEDIENTS APPLIED IX COMMERCIAL FERTILIZERS ON PLOT TWO AND THREE. 



I3 



Pliospboric acid, mostly dissolved 



Phosphoric acid, undlssolTed 



Potash 



Nitrogen 



250 

 50 

 14 



80 



With the exception of the oat crop of 1891 the production of 

 plot two has largely exceeded that of plot three. Especially is 

 this true of the 1894 crop after the exhausting effect of three years 

 of cropping. In this year the greater productiveness of plot two 

 is very marked, the excess of yield being 566 pounds of dry matter. 

 This is certainly one instance of the unmistakable persistent influ- 

 ence of a crude phosphate in increasing the growth of a field crop. 



In comparing the relative effect of the barn manure and the com- 

 mercial fertilizers it is cleai'ly seen that for the first three crops the 

 former caused the greater increase of production. If we compare 

 the plant food furnished to each of the several plots, this appears 

 to be a most natural result as much the larger amount was applied 

 to the barn manure plot. 



