22 



EXPERIMENT STATION BULLETIN 354 



Amount of gypsum 



Yield per acre 



Increase in yield 

 over no gypsum 



None 



500 lbs. 

 1000 lbs. 

 2000 llxs. 



246.6 bu. 

 ni.1 bu. 

 304.0. bu. 

 305.8 bu. 



-0- 



16.1 bu. 

 57.4 bu. 



59.2 bu. 



Supplementing normal fertilization with gypsum, not in excess of 

 1000 pounds, would appear to be a profitable practice in the Colebrook 

 area. 



The fertilizer-placement experiment involves a comparison of broad- 

 casting with banding. The results follow : 



Method of application 



Yield per acre 



Reduction in yield 

 below banding 



N, P and K banded 

 N and K broadcast, P banded 

 N broadcast, P and K banded 

 N, P and K broadcast 



These results are not identical with those of previous years, but there 

 IS evidence that over a period of years greater yields may be obtained by 

 banding all ingredients than by any other method of applying fertilizer. 

 The method of banding complete fertilizers by machinery has the added ad- 

 ^'antage of economy of application. 



Another fertilizer experiment on potatoes consists of comparing 

 various ratios of ingredients, while the amount of nitrogen was kept at a 

 constant level of 80 pounds per acre. 



Fertilizer application 



Analysis 



Ratio of 

 ingredients 



Pounds 

 per acre 



Yield 

 per acre 



Increase in 



yield above 



the 1-2-2 ratio 



The resulting variations in yield were narrow ; consequently no def- 

 inite conclusios can be drawn as to the relative profitableness of the various 

 applications. 



In addition, the above three lines of work upon which yield records are 

 obtained annually, three rotations are in progress in which potatoes are 

 grown (1) in continuous culture, (2) in a two-year rotation with cover 

 crops in the alternate year, and (3) in a fottr-year rotation in which oats 

 and two years of hay are utilized. Studies of organic matter and soil 

 structure are to be made of samples collected at the beginning and at the 

 end of a five-year period. 



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