QUESTIONS 



27 



To Distinguish Soil Classes. Procedure. Proceed as in Exercise No. 3, 

 only number the samples instead of naming them. Provide a new set of 

 samples if possible. Include muck and peat in the unknowns. Determine 

 the soil classes. 



To Determine the Difference in the Weight of Soils. Procedure. Fill a 

 small baking powder can full of air-dry sand and weigh. In the same manner 

 weigh a dry sandy loam, a silt loam, a clay, a muck, and a peat. Use a 20-mesh 

 screen to separate out all coarse particles. Record results as follows: 



Questions. (a) What is a so-called "heavy" soil? 

 (6) "Light "soil? 



(c) What per cent heavier is the dry clay than the peat? 



(d) What per cent heavier is the dry sand than the peat? 



To Learn How to Use a Soil Map. Procedure. Procure from the State 

 Experiment Station, College of Agriculture or from the United States Depart- 

 ment of Agriculture several soil maps of counties in the state. Select one 

 county map and answer the following questions: 



(a) 

 (b) 



Soil map of what county? 



Give the boundary of the county in terms of township and range. 



Does this description check with that on the state map? 



Name the predominating soil classes found in the county. 



Name the predominating soil types found in the county. 



Give the land description of the section of land in the northwest corner 

 of the county. 



(g) Name the types of soil mapped in this section. 



Field Studies. 1. Observe different soils based on mode of formation. 



2. Observe different types of soil and note why different types. 



QUESTIONS 



1. What are the common meanings given to "soil"? Subsoil? 



2. What does a farmer mean when he says, " My soil is three feet deep and is 



underlaid by sandy clay?'' 



3. In our study of soils in relation to crop production what is the meaning 



of soil to be understood? What then is subsoil to mean? 



4. Name and describe the soil components. 



5. Is soil a simple or complex substance? Explain. 



6. What is the most convenient way of classifying soils? 



7. Distinguish between soil texture and structure. What makes a soil coarse 



textured or fine textured? What structures may soils have? 



8. Name the eight principal soil classes based on texture in order from the 



coarsest to the finest textured. Give meaning of soil class. 



9. A certain soil is found to contain 2 per cent coarse sand, 3 per cent medium 



sand, 22 per cent fine sand, 35 per cent very fine sand, 27 per cent silt, 

 and 10 per cent clay. To what class does this soil belong? 



10. What two meanings may be given to "sand"? To clay? 



11. What is meant by "loam"? Clay loam? Fine sandy loam? Grav- 



elly loam? 



12. How are "marsh" and "swamp" soils to be regarded? 



