SOILS. 3 1 



tion of the fertilizer upon the particles of soil reduces 

 their size, thereby making them more retentive of 

 moisture. This, however, has not been demonstrated. 

 It is a fact well known to every observing cultivator 

 of the soil that good barnyard manure spread upon a 

 portion of the field conspicuous for its dryness will re- 

 sult in a good showing of moisture during the dry sea- 

 son. If a soil is too wet, it is frequently made more so 

 by the addition of well rotted manure ; but if it be un- 

 derdrained, the results will be most pleasing and profit- 

 able. 



Percolation through Frozen Ground. 



The impression is quite general that while the ground 

 is frozen there can be little or no percolation through 

 it. This is far from being true. As soon as the sur- 

 face of the ground becomes slightly softened by the 

 action of snow or rain, the shrinkage-cracks, worm- 

 perforations, and root-courses always present in the soil, 

 at once become available for the passage of drainage- 

 water, and as a result underdrains may be operative in 

 midwinter. Water is filtered through the soil and its 

 fertilizing ingredients deposited in the soil below the 

 frost line. 



The freezing of the soil, however, is of great assist- 

 ance in *^ fining *' the surface, disintegrating the grains 

 composing the subsoil, and, as above noted, adding 

 fertility by the process of filtering surface wate'r. It is 

 readily understood that frost penetrates a drained soil 

 deeper than a saturated one because the atmosphere 

 takes the place of removed water. For this reason the 



