204 AGRICULTURAL EXPERIMENT STATION. [Jan. 



As a first year's results, the above statements were pub- 

 lished without any further comment beyond the remark that 

 the exceptional dryness of the season might have favored a 

 superior action of the soluble phosphoric acid as compared 

 with the insoluble one. Attention was also called to the 

 important circumstance that an accumulation of phosphoric 

 acid in the soil might eventually aftect the results as time 

 advances. The largest yield of potatoes had only removed 

 3.4 pounds of phosphoric acid from the soil. 



Plat I. received 24.18 pounds of phosphoric acid. 

 Plat II. received 28.01 pounds of phosphoric acid. 

 Plat III. received 109. G8 pounds of phosphoric acid. 

 Plat IV. received 3G.12 pounds of phosphoric acid. 

 Plat V. received 12.31 pounds of phosphoric acid. 



Tabular Statement of the Approximate Amount of Nitrogen^ 

 Phosphoric Acid and Potash in the Crop raised. 



The calculation is based on E. Wolff's average analyses, 

 1,000 pounds of potatoes containing : nitrogen, 3.4 pounds ; 

 phosphoric acid, 1.6 pounds; and potassium oxide, 5.8 

 pounds. 



2891. — The experiment was continued by selecting win- 

 ter wheat as the next crop to be raised. For this purpose 

 the soil was ploughed soon after the potatoes had been har- 

 vested, and subsequently manured and harrowed, as in case 

 of the preceding crop. The change in the mode of manuring 

 the different plats was confined to Plat III., which received 

 no ground apatite, for the reason that none could be obtained 



