NATURE OF SOIL 235 



TOPICS FOR INVESTIGATION 



1. Select a spot on ycur home farm representing its 

 typical soil, dig down .with a spade or soil auger and take 

 two samples, one from a depth of six inches, and one of 

 twenty inches. How do the samples differ (1) as to texture, 

 (2) as to organic matter, (3) as to structure? How deep 

 does the humus extend? Bring samples to school, and 

 compare with those from the different farms represented. 



2. Place some of each sample in a bottle or glass of 

 water and mix well. Allow the sand to settle (How long?), 

 and pour the water off the top into a third receptable. Allow 

 the clay to settle until the water becomes clear. (How long 

 is required ?) Now determine as nearly as you can what is 

 the proportion of clay, silt and sand in the soils. How would 

 you name the texture of the soil on your farm ? 



3. Secure a sample of the soil from some cultivated hill- 

 top, and examine it for its texture, structure and the 

 amount of organic matter. Compare with another sample 

 taken from the foot of the hill. Explain the difference in 

 color. Dig down with a spade and compare the depth to 

 which the humus extends in each case. 



4. Are there any cultivated hills on your farm steep 

 enough that erosion is considerable? If so, how does 

 the yield on the hill compare with the lower land ? Are 

 there any gullies forming? If so, how long have they been 

 washing out ? What is being done to stop them ? 



5. Determine what kind of soil there is in your school 

 yard, such as silt loam, clay soil, or sandy loam, and com- 

 pare the aggregate surface of the particles of a cubic foot of 

 it with the area of the school grounds. 



6. What is a soil auger and for what is it used ? What 

 is a soil survey, and how and why is it made? Consider 

 the possibility of joining with your classmates in making a 

 soil survey and a soil map of your district. 



