24 AGRONOMY 



PRACTICAL EXERCISES 



1. In the school garden measure the depth of the soil by making an 

 opening down to the subsoil. Compare this as to depth with any other 

 soil sections with which you are familiar. 



2. Ascertain from wells, railway cuts, trenches for sewers, and the 

 like the average depth of the mantle rock in your vicinity. 



3. If the mantle rock varies in depth in your locality, make a table 

 to show this. 



4. Make a collection of specimens to illustrate the kinds of rock in 

 the table on page 22. 



5. Make a list of the different kinds of bed rock in your vicinity. 



6. Visit a gravel pit and collect as many different kinds of rock 

 fragments as possible. 



7. Make a list of all the above-mentioned fragments that are unlike 

 the bed rock in your region. 



8. Visit the best farm or garden in the vicinity and decide whether 

 the soil is a sedentary or a transported one. 



9. Visit the nearest outcrop of rock and search for signs of weath- 

 ering. Make a list of all forms seen. Decide which is more effective 

 in that place. 



10. Make a similar visit to a field on a hillside. 



11. Account for differences in the color of the soil on hilltops and 

 in lowlands. In which are the crops best ? Why ? 



References 



Dryer, "Lessons in Physical Geography." 

 Gilbert and Brigham, "Physical Geography." 

 King, "The Soil." 

 Salisbury, "Physiography." 



