52 



EXPERIIVIENT STATION. 



[Jan. 



The first of these tables shows that, although nitrate of soda, 

 when used alone, does not increase the crop, it gives a small 

 increase when used in connection with either of the other 

 fertilizer materials alone or with the two too-ether. The niti'ate 

 when used in connection with either potash alone or with potash 

 and dissolved bone black has apparently at the same time in- 

 creased the yield of grain and decreased that of stover. No 

 explanation of this result can be offered. We have, however, 

 figm-ed results on the weights of field-cured stover, and it is 

 possible that variation in moisture content obscures real effects, 

 although this is not believed to be the case, as similar results 

 have been obtained in other 3^ears. 



The second of these tables shows that, while phosphoric acid 

 used alone gives no increase, it gives a moderate increase both 

 in orrain and in stover when used with either of the other ferti- 

 lizer materials or with both. It will be noticed that on the 

 average the value of the increase in crop due to the use of the 

 phosphate exceeds the cost of that fertilizer. 



The third table shows the results obtained by the use of 

 potash. The fact is at once evident that this is the dominant 

 element for the corn crop in this soil. It will be noted that 

 even when used by itself it gives a large increase. It seems 

 surprising that the increase produced when the potash is used 

 in connection with both the other fertilizer elements does not 

 compare more favorably with the increase when it is used alone. 

 We have, it is true, a somewhat larger increase in grain. On 

 the other hand, the increase in stover is not as great as that 

 produced when the potash is used alone. The value of the in- 

 crease produced by the use of potash greatly exceeds the cost 

 of this fertilizer element. 



