EXERCISE A-28. TO SHOW THE EFFECT OF DRAIN- 

 AGE UPON SOIL TEMPERATURE. 



Equipment: Two one-quart tin cans; thermometer; 

 loam soil. 



Method: Make several holes in the bottom of one can 

 by driving a nail through it. Fill each can with the same 

 kind of soil. Wet the soil in both cans thoroughly. Push 

 the bulb of a thermometer one inch deep in each can and 

 place in a sunny window. Record the temperature every 

 two hours, continuing the readings on the second and third 



How does the temperature of the soil affect the growth 

 of crops. 



When is this most important? What would you do for 

 a soil that is wet and cold? 



Discussion: If we were to place a pan of water and a 

 pan of dry soil on a stove, we would find that it took longer 

 to heat the water to a given temperature than the dry soil. 



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