SOIL MOISTURE 253 



water begins to drip from the bottom of the funnel. Note 

 carefully how much water was required in each case. 



Soil texture and capillary water. Because of the 

 fineness of their texture, clay and silt soils have much 

 greater capacity for capillary water than sandy .or gravelly 

 soils. Under average field conditions the difference in the 

 amount of capillary water held in the first two feet of fully 

 saturated soil is about as follows: 



Sandy loam soil will hold __________________ 5 inches of water 



Clay loam soil will hold -------------------- TV* 



Muck soil will hold 



This is to say that it would require a sheet of water five 

 inches deep to supply the capillary water for the first two 

 feet of saturated sandy soil ; a sheet of water seven and one- 

 half inches deep for the-first two feet of saturated clay soil; 

 and a sheet twelve and one-half inches deep for the first 

 two feet of saturated muck soil. 



Drawing ground water by capillarity. A very simple 

 experiment will test the capacity of different soils for draw- 

 ing capillary water from below. Take four glass tubes at 

 least one inch in diameter and from fifteen to twenty inches 

 long, or four chimneys from student-lamps, and arrange 

 them suspended in a rack. Tie over the lower end of each a 

 piece of cheese-cloth. Fill the tubes with soils of different 

 texture, from fine clay to coarse sand. Place a pan beneath 

 the tubes, and pour water into it until the water stands half 

 an inch above the bottom of the tubes. Now watch the wa- 

 ter rise in the different soils. Keep accurate track of the 

 time required, and of the height reached in each. What 

 are your conclusions? 



Humus and capillary water. The capacity of any 

 soil for holding capillary water is greatly increased by the 

 presence of decaying organic matter. It has been care- 



