FIELD EXPERIMENTS IN 1915. 5 



The land had been plowed the preceding fall. In order to 

 insure a supply of nitrogen, a good coating of manure was ap- 

 plied to the two acres in the spring and the land plowed again. 



All plots were seeded with Prosperity oats using 3 bushels to 

 the acre. Owing to the pressure of other work it was found 

 impossible to thresh the grain from each plot separately. In- 

 stead the total weight of the unthreshed grain from each plot 

 was recorded. In this way a very good estimate of the yield 

 of grain can be obtained. 



Of the 4 plots, the first received no commercial fertilizer at 

 all. The second plot received 150 pounds of a 16 per cent acid 

 phosphate. This is equivalent to about 48 pounds of available 

 phosphoric acid per acre. The third plot received finely ground 

 Florida rock phosphate at the rate of 500 pounds per acre. 

 This raw rock analyzed about 31.45 per cent of total phosphoric 

 acid, making the application of total phosphoric acid about 150 

 pounds per acre. The fourth plot received a 5-8-7 commercial 

 fertilizer at the rate of 500 pounds per acre. 



The first 3 plots yielded at approximately the same rate. The 

 total weight of the straw and grain from these plots was at the 

 rate of about 2,800 pounds per acre. This corresponds with a 

 grain yield of about 40 bushels per acre. The variations be- 

 tween the yields of the different plots were not great enough to 

 be significant. The fourth plot which received the complete 

 fertilizer gave 3,900 pounds of grain and straw per acre. This 

 corresponds to a yield of about 56 bushels of grain. This shows 

 an increase of 16 bushels or 40 per cent over the plots receiving 

 no fertilizer or phosphoric acid alone. 



The results of this experiment indicate that phosphoric acid 

 is not a controlling factor in the yield of oats under Aroostook 

 Farm conditions. There was no significant difference between 

 the yield of the control plot and the plots containing either acid 

 phosphate or Florida rock. When a complete fertilizer was 

 used, however, a very significant increase (40 per cent) in 

 the yield occurred. The experiment was not planned in such a 

 way as to indicate whether this latter increase was due to tiie 

 ■nitrogen or to the potash. 



It is not expected to repeat this experiment in 1916. But it i; 

 planned to begin the preliminary cropping of a suitable area 



