Maine Agricultural Experiment Station. 1917. 117 



From the results of these 3 years it appears that at least 

 2-3 of the total nitrogen can be supplied in the form of sulphate 

 of ammonia without decreasing the yield. It is planned to con- 

 tinue these experiments in order to determine the effect of these 

 different substances under a number of different seasonal con- 

 ditions. 



METHOD OF APPLICATION OF FERTILIZER UPON 

 POTATOES AT AROOSTOOK FARM. 



It has always been more or less customary in growing po- 

 tatoes in Maine to apply the fertilizer in the drill or hill at the 

 time of planting. This was largely the practice when farm ma- 

 nures were used in connection with potato growing and has- 

 been followed with commercial fertilizers. Although now 

 when farm manures are used in connection with potatoes they 

 are more likely to be applied broadcast and a smaller amount 

 of fertilizer applied in the drill. There was little question in the 

 minds of practical growers that when 500 to 1000 pounds of 

 fertilizer were applied per acre that it was to the best ad- 

 vantage to apply it in the drill. With the increase up to 1,500' 

 to 2,000 pounds per acre the question has arisen whether it may 

 not be advisable to apply the fertilizer at different times. This 

 led the Station to undertake a series of trials at Aroostook 

 Farm. 



In 1914 an experiment was started to extend over a period 

 of years for the purpose of testing the method of applying fer- 

 tilizer. Something over acre plots were used. Three plots were 

 used in the experiment in 1914. To one plot all of the fertilizer 

 was applied in the planter at planting. To another plot 1,000 

 pounds of fertilizer were applied at planting and 500 pounds when 

 tlie potatoes were up. xA.nd to a third plot 1,000 pounds were ap- 

 plied broadcast before planting and 500 pounds in the planter 

 at planting. The Lowell Strain of Green Mountain potatoes 

 was used for seed. The crop was well cultivated and sprayed. 



The experiment was repeated in 1915 and a plot was added 

 to which all of the fertilizer was applied broadcast before plant- 



