Grade. 

 Date. . 



(36) EXERCISE 12 



Effect of Lime and Other Chemicals on a Clay Soil 

 Purpose. — To show that some chemical materials cause the soil to l^ecome 



more mellow and to crumble more easily, while other materials have 



the opposite effect. 

 FlocculaUon is the collecting together of very fine particles into clots or 



granules. 



PLAN 



1. Powder thoroughly in a mortar four ten-gram samples of clay soil and 



place in glass bottles. 



2. Fill the bottles about two-thirds full of water. 



3. Leave the first untreated but add chemicals to the other three bottles 



according to the following table. Pour some of the solution into a beaker 

 and then measure the exact amount with a graduate. 



4. What difference do you notice in the appearance of the solutions in the 



four bottles? 



5. Examine some of the material from each bottle under a microscope and 



make observations. 



6. Allow bottles to stand and note' time required for the particles to settle. 



Clean carefully the beaker and graduate after each solution is used. 

 Results 



QUESTIONS 



1. What material did you find most effective in producing flocculation? 



2. How is a clay soil benefited if its particles are brought together in flakes? 



3. What form of lime would act the quickest on a clay soil? 



4. What form of lime might be more satisfactory on a sandy soil ? 



5. How much should be used per acre on a sandy soil and how much on a 



clay soil? 



6. Under what conditions would lime benefit a sandy soil? 



7. Discuss the action of acid phosphate on the soil. Does it cause soils to 



become acid? How? 



8. What effect has the continuous use of nitrate of soda upon soil structure? 



