EXPERIMENT STATION BULLETINS. 



609 



matter Feb. 3rd; 2.01% February 5th; 3.32% February 6th; 5.47% Feb- 

 ruary 7th; 6.95% February 10th; and peat February 15th. 



The temperntuve of tlie u])per 5 inch depth of all the soils fluctuated, 

 after the freezing point was reached, as the average temperature varied, 

 and the amount of flucluaHon was greatest when the soils were not 

 covei*ed with snow. The lowest average temyierature reached by all the 

 soils at the upper depth, was on Feb. 6th with the following results: 

 1.81% 16.26° F., 2.01% 16.80°, 3.32% 17.46°, 5.47% 18.56° F.. 6.95% 

 19.20°, peat 22.50°. After this date the temperature tended to fluctuate 

 from the above points to 32° until the thawing period. 



From the time of thawing to the end of Se})tember the soils with 2.01, 

 3.32, 5.47 and 6.95% organic matter showed a higher daily and monthly 

 average temperature than the soil with 1.81% and peat. This was true 

 at both depths. The temperature of the first three soils tended to be 

 about the same through all the wanner months with a slight difference 

 in favor of the soil with 3.32% organic matter. The temperature of 

 peat ran considerably lower than that of the soil with 1.81% organic 

 matter up to the end of June. From this; time on until the freezing 

 period the temperature of both soils ran about the same with a slight 

 difference in favor of peat. 



It will now be worth Avhile to study the moisture content of these 

 soils and compare this with their heat relationships and thereby see to 

 what extent the object of this research has been answered. 



The water content of these soils was determined several times during 

 the warmer part of the year, but for the sake of brevity, only three 

 determinations will be given, namely those taken April 3rd, when the 

 soils commenced to thaw, July 27tli, in the warmest month of the year, 

 and November 4th, when the rapid cooling commenced. The data are 

 represented herewith : 



TABLE 59. 



-MOISTURE CONTENT OF SOIL WITH DIFFERENT AMOUNTS OF ORGANIC MATTER. FIVE 



INCH DEPTH. 



Date. 



April 3.... 



July 27 



November 4 



Peat. 



256.5 

 236.4 

 247.8 



It will be seen that the moisture content for all the soils varied con- 

 siderably at the different times, but it increased very markedly in all 

 of them, with the increase of the organic content. In the determinations 

 of July and November the soil with 6.95% organic matter contained 

 about 9 times as much water as the soil with only 1.81%, while the peat 

 possessed almost 120 times as much as the latter and about 12 times 

 as much as the former. 



These facts lead to the important conclusion that color plays an 

 important part in the warming of the soil and contradicts the common 

 belief that its influence or effect is overbalanced or overshadowed by 

 the greater moisture content that the colored soils tend to possess. 

 The results above show conclusively that when the soils are colored, 

 77 



