EXPERIMENT STATION BULLETINS. ^ 805 



peratiire in the winter which would be detrimental to vegetation, A 

 vegetation cover coupled with snow certainly forms a very powerful 

 soil temperature protector. 



EFFECT OF SNOW ON THE SOIL TEMPERATURE. 



From the theoretical standpoint a layer of snow ought to protect the 

 soil against very severe cold weather and keep its temperature higher 

 and steadier. Its effect would seem to be analogous to that of a vegetation 

 cover. It ought to act as a blanket and reduce the rapid loss of heat 

 firstly by preventing the convection and wind currents from coming in 

 contact with the surface soil, and secondly, on account of its poor heat 

 conductivity. 



When the thickness of the layer is rather large, snow is certainly 

 a most eflScient agent in protecting the soil from very low temperature. 

 Observations have been made upon the subject through four successive 

 winters and the results obtained are exceedingly interesting and of 

 great practical importance. Some of these results have already been 

 published in the previous report. In the present paper will be presented 

 only the data collected during the month of January 1915. The obser- 

 vations conducted during this year consisted of noting the temperature of 

 soil at 3 inches deep under the following conditions: (1) bare, (2) cov- 

 ered Avith compacted snow, (3) covered with uncompacted snow, and (4) 

 covered with layer of vegetation and uncompacted snow. Table 88 con- 

 tains the daily and monthly maximum, minimum, amplitude, and average 

 temperature for the month of January. 



