204 Artificial Manures for Potatoes. 



(2) superphosphate and nitrate of soda ; (3) superphosphate, 

 nitrate of soda, and kainit; (4) superphosphate and kainit ; 

 all the manures being applied in the drills at the time of 

 planting. The superphosphate was used at the rate of 

 6 cwts. per acre, while 2 cwts. of nitrate of soda and 

 3J cwts. of kainit were applied per acre. In some 

 cases the crop from a portion of land on the dunged part of 

 the field, equivalent in area to the experiment plot, was 

 weighed for comparison, while in other cases the results were 

 estimated by general observation. The total and average 

 yield of potatoes each plot was as follows : — 





Plot 1. 



Plot 2. 



Plot 3. 



Plot 4. 





Superphosphate 



Superphosphate 



Superphosphate, 



Superphosphal 





alone. 



and N itrate. of 



Nitrate of Soda, 



and Kainit. 







Soda. 



and Kainit. 







lbs. 



lbs. 



lbs. 



lbs. 



Total yield of 15 plots 



2298 



2832 



3258 



2878 



Lowest and highest 



yield 









per plot 



98-269 



102-279 



126-320 



110-273 



Average yield per plot 



i53 



189 



217 



192 



As superphosphate was used on all the plots, the results 

 serve to indicate the effects of the addition of nitrate of soda 

 and kainit separately and in combination. It will be noticed 

 that the average yield on the plots which received nitrate of 

 soda and kainit exceeded that obtained from the plot dressed 

 with superphosphate alone. On plot 3, which received both 

 kainit and nitrate of soda in addition to superphosphate, the 

 increase on the average yield on plot 1 was 64 lbs. per plot, 

 while on plots 2 (superphosphate and nitrate of soda) and 4 

 (superphosphate and kainit) the increase amounted to 36 lbs 

 and 39 lbs. per plot respectively. Calculated to the acre the 

 increments on plots 2 and 4 amount to approximately 

 18 cwts. per acre in each case over plot 1, and on plot 3 the 

 increase was over a ton and a-half per acre. These quantities 

 are regarded as good returns for the manures applied, and 

 particular attention is directed to the fact that the profit 

 arising from the use of the three manures together on plot 3 

 was considerably greater than that obtained on the plots 

 from which one or more of the manures was omitted. 



