ICG 



Physics of the Soil. 



Table showing the loss of water by surface evaporation from 

 columns of soil 10 feet long^ mulched and not mulched. 



In the case of the sandy loam the lower six inches in each 

 case is wetter than when it went in, showing that at first 

 percolation downward had taken place, and as this soil 

 when allowed to drain freely only retained 19.44 per cent, 

 of water at a depth of 36-42 inches, it is quite probable 

 that at some time the lower soil 10 feet below the sur- 

 face may have been wetter than found at the end of the 

 trials, and if this is true then even the sandy loam has 

 lost water upward from a depth of ten feet below the sur- 

 face. 



It is quite certain that a drying of these soils has taken 

 place through a depth of ten feet, and hence that moisture 

 ten feet below the surface of the ground may become 

 available for vegetation purposes at or near the surface. 



The effective diameter of the soil grains in these two 

 cases was found to be, for the sandy loam, about .01635 

 m. m., and for the medium clay loam, .01254 m. m. ; thia 

 would indicate that there might be a capillary rise of 23.6 

 and 30,8 feet respectively. 



