Grade. 

 Date. . 



(34) EXERCISE 11 



Influence of Weathering, Organic Matter, Sand and Lime on 

 A Clay Soil 



Purpose. — To determine best system of management for a clay soil. 



plan * 



1. Take five of the shallow square pans and weigh into each 400 grams of 



pulverized clay. 



2. To pan No. 3 add 100 grs. of muck nnd mix thoroughly with the clay. 



3. To pan No. 4 add ten grs. of lime and mix thoroughly. 



4. To pan No. 5 add 10 grams of sand and mix. 



5. Leave pans 1 and 2 without addition. 



6. Add water slowly and mix each with a steel spatula to a stiff puddled 



condition. Be very careful not to add too much water. 



7. Take pan No. 1, which contains pure clay, and scratch with a knife blade 



to a depth of one-eighth of an inch one-third of the surface, arranging 

 the scarifications one-fourth of an inch apart in both directions. 



8. On a cold night set the untreated pan No. 2 out-doors and allow it to 



freeze solid in its wet state. 



9. Set the other four pans away and allow them to dry out thoroughly. 

 10. Later examine the pans and answer the following cjuestions. 



QUESTIONS 



1. State the effect of muck, lime, sand and organic matter on the hardness 



of a clay soil. Discuss. 



2. Does the sand appear to have improved the tilth of the clay soil? Would 



it be profitable farm practice to apply sand to a clay soil? Why? 



3. Does freezing tend to mellow and crumble a puddled clay soil? What 



does this indicate as to the time of plowing? 



4. How are the ice crystals formed? 



5. What influence do the checks have on the structure of the soil? 



6. From the results of this experiment outline a system of management for 



a heavy clay soil. 



7. How do commercial fertilizers compare with manure in improving a clay 



soil? 



8. What form of lime would give the quickest results on a clay soil? (See 



next exercise). 



9. How many pounds would you use per acre? How should it be applied? 



* Adapted from Department of Soil Technology, Cornell University. 



