30 



N. H. AGR. EXPERIMENT STATION. 



[BuUetin 170 



Observations have been made on two clover crops to deter- 

 mine if the natural potassium supply would meet the require- 

 ments of this crop. Clover requires a considerably larger 

 amount of potassium than does timothy. The following data 

 shows the effect of the addition of potassium fertilizers on the 

 potassium content of the crop. 



Table XXIII 



The following table shows the effect of nitrate of soda on the 

 potassium content of the crop: 



Per cent. K2O in clover from 

 check plots 



Per cent. K2O from plots treated 

 with nitrogen 



2.41 

 1.49 



2.22 

 1.56 



1.66 

 1.79 

 2.28 

 2.16 



Average 1 . 92 



Average 1 . 97 



The clover on the plots fertilized with nitrate of soda alone, 

 and with potash alone, contained, on the average, a very little 

 more potassium than the average amount found on the check 

 plots. It has not been possible to secure enough data to deter- 

 mine the effect of potassium fertilizers on the yield of clover. 



