Grade 

 Date. 



(66) 



EXERCISE 2,'^ 



Drainage and Soil Temperature 

 Purpose.— To show the influence of stancUng water in a soil upon its tem- 

 perature. 



PLAN * 



1. Prepare two similar vessels — one water tight and the other with holes to 



allow of good drainage at the bottom; these may be two tubs or boxes. 

 Fill them with the same kind of soil to a depth of six inches. 



2. Plant an equal number of grains of corn in each box. 



3. Sprinkle equal quantities of water upon each vessel until it begins to drain 



from the box with the perforated bottom. Repeat this as often as is 

 necessary until the corn is well up. 



4. After ten or twelve days insert the thermometers and determine hourly 



the temperature of each at 1, 2 and 4 inches in depth. 



Results 



Date of recording thermometer readings 



No. of plants on drained soil On undrained soil . 



QUESTIONS 



Why is there a difference in temperature? 

 Why are clay soils often cold or colder than sandy soils? 

 Why does corn often rot in the ground during a wet spring? 

 Name some of the benefits of drainage to the farmer. 

 What is the difference between natural drainage and artificial drainage? 

 Why is the latter necessary and what is the most successful method of 

 carrying it out? 



"Adapted from Mosier. 



