520 



STATE BOARD OF AGRICULTURE, 



TEMPERATUKE OF DIFFERENT TYPES OF SOIL. 



OBJECT AND METHOD OF EXPERIMENTATION. 



This phase of the project had for its primary purpose- the investiga- 

 tion of the tem]K'rature. under field conditions, of tlie most common 

 and representative ty])es of soil, namely, oiavel, sand, loam, clay and 

 peat. These soils possess so many distinct dilTerences in their physical 

 and chemical properties that it was desired to ascertain whether their 

 tcmpcratuif relationships would also be different. The mechanical 

 analysis, as determined by the ceii1rifup:e method, and the percentage of 

 oi'ganic matter, as delermined by Ihe loss on ignition method, of these 

 soils, are shown in the following table: 



T.ABLE lS.n.- MECHANICAL .\XALYSIS AND PERCENTAGE OF ORGANIC M.VTTER OF THE DIFFERENT 



TYPES OF SOIU 



Our knowledge concerning the temperature of these different types 

 of soil is very meager. Only two investigators appear to have studied 

 the subject : ^''Wollny and ^"Ebermayer. Wollny made observations of 

 the tiemperature of sand, clay, and peat for long time. He noticed that 

 sand heats and cools with the greatest rapidity followed by clay and 

 IX'at and that their average temperature of long period differs but slight- 

 ly. Ebermayer studied the temperature of sand, clay, loam and peat. 

 From the data he obtained he arrived at practically the same conclu- 

 sions as Wollny. 



The present investigation was conducted in the following manner: 

 A long trench was dug on a smooth and slightly rolling j)iece of ground 

 a little over 3 feet deep and 3 feet wide. A layer of sandy soil about 

 (*» inches deej> was spread over the bottom of this trench so that there 

 would be a uniform bottom. Into this trench, about one foot a}>arl, 

 were placed five wooden boxes 3x3x3 feet without bottom or toj). 

 These boxes were first filled with the above different types of soil about 

 the latter part of September, 1911, were flooded several times in order 

 to compact, and finally were covered with a very thin layer of the same 

 kind of s<jil in order to eliminate the factor of color. The effect of this 

 factor was investigated in a separate experiment. Their temperature 

 recording was preliminarily begun in the middle of November, but was 



(15) Forsch. a. d. G. <i. ARrik. Phy. XIX: 305. 1S06. 



(16) Forsch. a. d. C. d. Agrik. Phy. XIV: 399, 1891. 



