1915.1 



PUBLIC DOCmiENT — No. 31. 



33 a 



In ease of the raspberries the sulfate plot produced at the 

 rate of 1,635 pounds per acre more than the muriate. Con- 

 sidering the raspberries worth 15 cents per quart it is seen that 

 the sulfate returned $196.20 more per acre than the muriate. 



The two salts are applied on the basis of equal applications 

 of actual potash, which means about 200 pounds per acre of 

 each. Used at these rates the sulfate cost this year about $1.05 

 more per acre than the muriate. 



The sulfate plot also ranks ahead of the muriate plot for the 

 crops of blackberries and rhubarb. The muriate plot, however, 

 ranks ahead in case of the asjDaragus, having a balance in its 

 favor of $19.05 per acre. 



Comparison of Potash Salts (Field G). 

 In this experiment we have had under comparison for seven- 

 teen years seven different materials that may be used as sources 

 of potash. There are 5 check or no-potash plots, and each ma- 

 terial furnishing potash is used on 5 different plots, thus mak- 

 ing 40 plots in the field. The crop this year was potatoes. The 

 following table gives the average yields per acre on the different 

 potash salts, also the relative standing of each : — 



Fertilizer. 



Large 

 (Bushels). 



Small 

 (Bushels). 



Total 

 (Bushels). 



Rank, No 



potash 

 equals 100. 



No potash, 



Kainit, .... 

 High-grade sulfate of potash. 

 Low-grade sulfate of potash, 

 Muriate of potash. 

 Nitrate of potash, . 

 Carbonate of potash. 

 Feldspar, 



122.80 

 129.40 

 173.53 

 159.70 

 177.40 

 190.83 

 193.33 

 124.13 



22.80 

 15.23 

 15.97 

 15.90 

 12.63 

 15.20 

 20.10 

 13.57 



145.60 

 144.63 

 189.50 

 175.60 

 190.03 

 206.03 

 213.43 

 137.70 



100.00 

 99.33 

 130.15 

 120.60 

 130.52 

 141.. 50 

 146.59 

 94.57 



The small ^aelds obtained are due largely to the fact that the 

 soil is badly infested with the potato scab fungus. 



Potatoes were grown this year for the purpose of studying, 

 in co-operation with the department of vegetable pathology, the 

 control of this fungus. The experiment will be repeated an- 

 other year. 



