312 



SOILS AND FERTILIZERS 



Repeat the experiment, using sand, and note the difference in 

 absorptive power. 



Repeat, using 95 per cent of sand and 5 per cent of dry and 

 finely pulverized manure. 



Experiment No. 3 

 Determination of the Capillary Water of Soils 



For this experiment a sample of soil directly from the field is 



to be used. The sample is to be 

 taken at a depth of from 3 to 9 

 inches or at any depth desired. 

 One hundred grams of soil are 

 weighed into a tared drying pan, 

 exposed in a thin layer to the room 

 temperature for 24 hours and then 

 reweighed. After an interval of 

 from two to four hours the soil is 

 weighed again, and if the weight is 

 fairly constant, the per cent of water 

 lost by air drying, representing the 

 capillary water of the soil at the time 

 of sampling, is calculated. This ex- 

 periment may be repeated, using 

 different types of soil, as sand, clay, 

 and loam. 



Experiment No. 4 



Capillary Action of Water upon 

 Soils 



FIG. 54. The Capillary Water of Firml y tie a P iece of linen cloth 

 Soils. over the end of a long glass tube 



4 inches in diameter, then fasten a piece of wire gauze over 

 the cloth. Fill the tube with sandy soil (No. i). Compact the soil 



