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EXERCISE 1 (13) 



Field Study of Processes of Soil Formation 



PLAN 



A. Examine a sample of soil and name all of the materials of which it is 



composed. How much organic matter is there in this soil? Show clearly 

 how this organic matter has been formed. Compare its age with that 

 of the inorganic matter. 



B. Study the work of the various soil-forming agencies which you find and 



discuss clearly and fully the part which each of these different actions 

 plays in the formation of the soil. 



1. Moving Ice. — Look for deep scratches on the solid rock which forms a 



part of the earth's crust. What is a glacier? How did it act in the 

 formation of soils in New York? 



2. Moving Water. — Examine the banks of a brook and find where the land 



has been built up on one side and cut away on another. Explain the 

 smoothness and roundness of the stones and other material in the bed 

 of the brook. AVhat effect has size upon the way in which the material 

 is deposited? Walk along the base of a steep hillside and note tlie effect 

 of water in bringing do^^^l soil. Is this action l)cneficial or injurious? 

 Why? How does a water-formed soil differ from that formed by ice? 

 How does the water grade the soil according to the size of particles? 



3. Chemical Action of Air andWat£r; Weathering. — Why do some rocks seem 



to crumble easier than others? Examine an old stone wall. Do the rocks 

 rest as securely as they did when they were first laid? ^^'hat has caused 

 certain rocks to crack open? 



4. Changes in Temperature. — Show clearly how the forces of heat and cold 



may cause rocks to crumble. 



5. Action of Living Plants and Animals. — Look for lichens growing upon 



rocks. What is the condition of the rock underneath and how do these 

 plants act as soil builders? Look for the roots of trees growing between 

 rocks. Discuss. Do j'ou find small roots of plants between layers of 

 rock? Look for the work of earthworms, also other animals. 



6. Effects of Organic Matter. — Examine a piece of iron which has been in a 



manure heap or a pile of decaying organic matter. Explain the action. 

 Examine a swamp and note how it has filled up. How is muck fomied? 



7. TFi'/jf/.^.— Find some soil transi)orted by winds. Is such action beneficial 



or injurious at the present time? Give two different kinds of soil which 

 are formed ])y the wind and state their location, composition, and agri- 

 cultural value. * 



C. Examine surface soil and subsoil. How do they differ? Describe each 



carefully. 



D. If possible, examine the soil of an old pasture which has never been 



plowed. Is the dark-colored surface soil as deep here as on land which 

 has been cultivated for several years? Why? 



