EXERCISE 5 



THE INFLUENCE OF VEGETATION ON SOIL TEM- 

 PERATURE 



Object. To determine the difference in temperature 

 between a soil covered with a growing crop and a bare soil 

 exposed to the direct sunshine. 



Explanation. The temperature of the soil is influenced 

 by its color, topography, moisture content, and the vegeta- 

 tion growing on the soil. The amount of moisture that the 

 soil contains is the principal factor affecting the temperature. 

 With soils of the same moisture content the soil upon which 

 there is a growing crop will be cooler than the one without 

 vegetation. 



Equipment-. 1. A soil auger. 



2. Eleven chemical thermometers. 



3. Fifteen feet of picture wire. 



Directions. Go to a garden or field where there is culti- 

 vated ground and also ground growing a crop such as grass, 

 alfalfa, clover, or any other dense-growing crop that shades 

 the ground thoroughly. 



With the soil auger make holes in both the cultivated and 

 the cropped ground to a depth of 3 inches, 6 inches, 1 foot, 

 2 feet, and 3 feet. In choosing a location for the holes care 

 should be taken to place them where the ground has the same 

 general direction of slope and the same angle of slope. 



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