636 STATE BOARD OF AGRICULTURE. 



The data show that when the soils were frozen there was very little 

 variation in tomporatnre at both depths not only within the same soil but 

 also among the dilleroiit soils, as evidenced by the results of March when 

 all the soils were still frozen. Immediately upon thawing and also after 

 that until the next freezing commenced the amplitude of the upper 5 inch 

 depth was quite marked, both within the same soil and among the dif- 

 ferent soils. In Ihe 18 inch depth, it was comparatively small. At 

 both depths, the soil with 3.32% organic matter gave the greatest varia- 

 tion in temperature followed by the soils with 2.01, 5.47, 1.81, G.95% 

 organic matter and lastly by pure peat. Evidently the soils with the 

 medium amounts of organic matter gave the gi*eatest amplitude while 

 those with the opposite extreme of organic matter gave the smallest. 

 This was exactly the way that their average tem])erature behaved. 



The fluctuations of the temperature of the soils A\ith the various 

 amounts of organic matter did not vary greatly among themselves with- 

 in the same day or month, but they varied with peat. It will be seen' 

 that the differences between the amplitudes of the former soils in the 

 upper .5 inches varied about 2° F. the most after the month of April, 

 but the differences between these fluctuations and those of peat were 

 comparatively very large, ranging in the month of June for instance, 

 12.72° F. between the peat and the soil with 3.32% organic matter. 



In the 18 inch depth the amplitudes tended to increase with the de- 

 crease in organic matter. The variations among the different soils, 

 including the peat, ran in about the same order of magnitude as in 

 the upper depth. 



The highest daily am])litude for the 5 inch depth occurred on April 

 30, and the highest monthly occurred in June for both depths. June 

 is followed in order by May, July, August, September, April, Octo- 

 ber, November, and December. 



