146 



Journal of Agricultural Research 



Vol. X, No. 3 



sand plus muck. Evidently where there is a large supply of moist soil, 

 the moisture will tend to distribute itself uniformly throughout the soils 

 to the full length of the tube. This tendency may be checked by an 

 insufficient length of time, a weak attraction of the more remote sections 

 for water, excessive frictional resistance such as is found in clay soils, or 

 an exhaustion of the supply before the remote soil is reached. 



Where Moisture; Moved Upward prom Different Son, Types to Greenvh^le 



Loam 



In this experiment studies were made of the ability of different soil 

 types to supply moisture to Greenville loam. This was done by placing 

 in bell jars, such as were used in a previous experiment, sand, clay, and 

 Greenville loam having 7.77, 24.62, and 31.09 per cent of moisture, 



PBrcenfog^ of raoisture in Gfeeni/iLLe Loam at varioui ditiantas 

 from source oi jupplt/ 



Fig. 26. — Diagram showing the distribution of moisture in air-dried Greenville loam in contact with sand 

 having 7.77 per cent, Greenville loam having 31.09 i>er cent, and clay having 24.62 per cent of moisture. 



respectively. Into these jars were then inserted the ^-inch glass tubes 

 filled with air-dry Greenville loam. A record was kept of the rates the 

 moisture rose in each of the tubes. After the experiment had run 94 

 days, the tubes were removed and moisture determinations made for 

 each 3-inch section of the tubes. 



In figure 26 it is seen that here, as in the two previous experiments, 

 the moisture content decreased with the distance from the source of 

 water. Sand with only 7.77 per cent of moisture raised the moisture 

 content of air-dry loam with which it was in contact to almost 30 per 

 cent, and caused an appreciable increase in the moisture to a distance of 

 over 30 inches. Clay containing 24.62 per cerxt of moisture, on the other 

 hand, raised the moisture of the loam only slightly and to a distance of 

 about 6 inches. When drv loam was left in contact with loam con- 



