608 STATE BOARD OF AGRICULTURE. 



Space does not permit full and detailed discussion of the results of 

 this experiment, hence only the ju'incipal points will be emphasized. 



All the soils at both depths remained frozen till April 4 on which day 

 the ujjper 5 inches of the soil with 2.01 and 3.32% organic matter 

 thawed, followed by the soils with 1.81, 5.4 and 6.95% organic matter 

 the next day and by peat 7 days later. The IS inch depth thawed in 

 the following order': 1.81% organic matter April 10, 2.017o April 10, 

 3.32% April 11, 5.27% April 12, 6.95% April 15, and peat May 4. Im- 

 mediately upon thawing the temperature of the soils with the lowest 

 percentage of organic matter rose the highest followed by the other two 

 soils in the order of their increased organic content. On the second 

 day after the first 1 hawing appeared, the temperature of the soil with 

 1.81% organic matter fell back from that of the soils with 2.01 Jind 

 3.32% organic matter but it was still ahead of Ihe temperature of the 

 soils with 5.42 and 6.95% organic matter. The temperature of the two 

 latter soils attained the same magnitude as the temperature of the soils 

 with the three lower percentages of organic matter, about April 15. 

 At about this time the lower depths of the soils with the higher per- 

 centages of organic matter thawed, hence the logical inference would 

 seem to be that it was ])robably these frozen layers below that delayed 

 the rapid rise of the temperature of these soils. The temperature of 

 the soils \xii\i the intermediate percentages of organic matter (2.01, 3.32, 

 5.47%^ tended to be higher than that of the soils with 1.81 and 6.95% 

 from the second or third day after thaAving to the end of the month of 

 April, and for all the time thereafter. The temperature of the soil with 

 1.81% organic matter was higher than that of the soil with 6.95% up 

 to the middle of April and from then on it was the latter that was 

 ahead. The temjx^rature of the peat did not attain the same magnitude 

 as that of the other soils until about May 11, or only a few days after 

 the lower depth had thawed. 



The temperature of all the soils at both depths continued to increase 

 until July when the maximum was attained and then it began to de- 

 crease until freezing time. The highest temperature was attained by 

 all soils at the upper 5 inch depth between the 9th and 11th of July. The 

 soil with 1.81% organic matter reached its average maximum on Julv 

 9th with 80.23° F., 2.05% July 9th with 82.26°, 3.32% July 9th with 

 22.33°; 5.47% July 11th with 81.03°; 0.95% July 11th with 82.23°; and 

 peat July 11th with 78.13°. At the 18 inch depth the highest average 

 temperature was reached bv the soil with 1.81% organic matter on 

 July 11th with 74°; 2.01% 'on Julv 11th with 74.23°; 3.32% on Julv 

 11th with 73.13°; 5.47% July 11th with 73.70°; 6.95% July 12th with 

 74.1°; and peat on July 12th with 72.72°. 



From this i>eriod on the temperature of all the soils at both dejiths 

 decreased somewhat irregularly but gradually until the freezing period 

 and then until the minimum was attained. The first freezing occurred 

 about the first part of December, Avhen the soils with the ditlerent 

 amounts of organic matter froze about the same time with small varia- 

 tions. The soils with 1.81, 2.01. and 3.33% organic matter froze at the 

 upper 5 inch depth on December 9th. with 5.47% on December 10th, with 

 6.95% on December 12th, and peat about December 13th. The 18 inch 

 depth of the different soils froze at the following dates: 1.81% organic 



