48 .Maine Agricultural Experiment Station. 1919. 



In 1917 (See page 25 Bulletin 269) the yields were un- 

 even largely because of the uneven stand due to seasonal 

 causes. The yields were published but are meaningless as re- 

 gards the effect of fertilizers. 



In 1918 the stands were fairly uniform and while not much 

 can be learned from a single year's results they are worthy of 

 study. 



Grouped by the plots at the points of the triangle and by 

 the center plots (See diagram page 38), the average yields 

 are : 



' Bushels grain 



Three ammonia plots, N3 in diagram 27 



Five ammonia plots, N5 in diagram 26 



Three available phosphoric acid plots, P3 in diagram 21 



Five available phosphoric acid plots, P5 in diagram 20 



Three potash plots, K3 in diagram 20 



Five potash plots, K5 in diagram 19 



Three center plots, Comp3 in diagram 22 



Five center plots, Comp5 in diagram 21 



Three lower center plots, Am4 in diagram 18 



Three left center plots, Phos acid side 21 



Three right center plots, Potash side 24 



Six check plots 23 



Although as discussed below there seems to be an uneven- 

 ness in the soil that was not expected when the test was begun, 

 the above tabulation indicates clearly that ammonia (nitrogen) 

 is the limiting factor in oat' production as it was found to be 

 in 1917 with potatoes on this Series. 



This is more clearly brought out in arranging the results, 

 as below, in the order of the ammonia (nitrogen) content. 



Six no ammonia plots 17 



Five 4 per cent ammonia plots 19 



Four 8 per cent ammonia plots 22 



Three 12 per cent ammonia plots 26 



Two 16 per cent ammonia plots 27 



One 20 per cent ammonia plot 29 



The inference from the first tabulation given above that, 

 phosphoric acid and potash had little influence on the yield is 

 shown in the following tabulations for these elements. The 

 series in the triangle that carried no ammonia are omitted since. 



