46 LABORATORY MANUAL OF AGRICULTURE 



purpose. Fill the crock with water until the water stands 

 about level with the top of the soil in the tubes. 



Take the time that the water was added. Note the time 

 that the first moisture appears on the top of the soil in each 

 tube. Record time required for water to appear in each 

 case. 



Allow the tubes to remain in the water until the soil is 

 thoroughly saturated. This will be about ten minutes 

 after water appears on the surface of the last soil. 



Remove the tubes one at a time, wipe off the excess water 

 with a towel, and quickly weigh. Record weights. 



Place the tubes on a draining shelf and cover with glass 

 plates to prevent evaporation of water at the surface of the 

 soil. 



Weigh after standing 15 minutes, 30 minutes, 1 day, 

 2 days, 3 days, 4 days, 5 days, 6 days. Wipe excess water 

 from bottom of the tube each time before weighing. Record 

 each weight in the outline form. 



QUESTIONS 



1. What is a saturated soil ? 



2. What effect has organic matter upon the water-holding power 

 of the soil ? 



3. Calculate the per cent of water held by each soil the sixth day. 



4. Calculate the number of pounds of water retained per cubic 

 foot of dry soil. 



