1917. 



PUBLIC DOCUMENT — No. 31. 



53 a 



As in previous years, when corn has been grown on these 

 plots, the largest yields are obtained on the plots where potash 

 is used. The materials are not used in such quantities as 

 would be expected to produce large crops. The continued use 

 for twenty-seven years of the same materials on the same plots 

 has furnished a mass of data as to the specific plant-food 

 requirements of different crops. 



Grass Plots. 

 The experiment in top-dressing permanent mowings with dif- 

 ferent materials used in rotation has been continued, but 

 owing to the scarcity of potash this material was not applied 

 the past season. In the following table will be found the 

 fertilizer schedule and the yields per acre obtained on each for 

 this year: — 



Fertilizers. 



Hay 

 (Pounds). 



Rowen 

 (Pounds). 



Total 

 (Pounds). 



Barnyard manure, .... 

 Bone and potash, ' . . . . 

 Slag and potash' (earlier ashes plot), 



4,630 

 4,267 

 4,450 



2,110 

 1,942 

 1,581 



6,740 

 6,209 

 6,031 



' No potash was applied in 1916. 



The average yields to date under the three systems of top- 

 dressing are: — 



Pounds per Acre. 



When top-dressed with manure, ...... 6,038 



When top-dressed with bone and potash, .... 5,911 



When top-dressed with wood ashes (slag and potash now used), 5,628 



The past season was very favorable to the production of a 

 large hay crop, and in spite of the fact that the potash was 

 omitted from the different mixtures the yields obtained on all 

 the plots were considerably above the average yields on these 

 plots. The results obtained this year would seem to indicate 

 that on permanent mowings, where it has been the custom for 

 several years to apply annually a liberal application of chemicals 

 or manure, potash may be omitted for at least one year and 

 still a normal crop be obtained. 



