EXERCISE 73 



HOW ARE SOILS FOKMED? 



Materials. The local environment ; soil-survey reports bearing upon local soils ; discussions 

 found in library materials. 



Directions. An excursion should be made into the adjacent country to study the soils. River- 

 bottom lands and uplands should furnish contrasting types of soils. Differences in both crops and 

 natural vegetation in correspondence with soil differences may be seen. Visit a rocky ridge or ravine 

 and study formation of soil by weathering, plant action, and stream work. If the region is within the 

 glaciated area, look for evidences of glaciation and glacial soils. 



Find out whether the area about the school has been surveyed by the Bureau of Soils, Depart- 

 ment of Agriculture, Washington, D.C., and if so, secure a copy of the report. This will give map 

 and details regarding soil types. The details of all such studies will change with the locality and 

 must be left to the pupils and teacher. 



Additional problem. How many types of soils are there in your locality ? Can you determine the causes 

 of the differences in these soils ? How do these soils differ with reference to production of crops ? 



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