Date. 



EXERCISE 19 



(51) 



Clod Formation 

 Purpose. — To study the clod-forming properties in soils of different kinds. 



PLAN 



1. Take small samples of each of the available soils of the region; include a 



sample of heavy clay soil; also include one mixture of sand with clay and 

 one of humus and clay. 



2. On a mixing board mix each with enough water to make as stiff a "putty" 



as each sample will make. Roll part of it into the form of an inch marble, 

 and another part into a half-inch cylinder about four inches long. 



3. Make up all the samples as nearly alike as possible. Label each by stippling 



a number on each kind. Put the molded samples into cigar boxes or on 

 shelves to dry for several days. 



4. Make studies of the relative breaking powers of these samples, and make 



a record of their clod-forming properties. 



Clod Formation 



Note. — If instruments are not available for measuring, crushing and breaking strength, 

 comparisons may be made after breakinia; with fingers. 



QUESTIONS 



1. Make a list of the samples in order — the hardest clods first. 



2. What interest has the farmer in the clod-forming properties of field soils? 



3. Which soils must be handled most carefully after rains? 



•i. Which are likely to form hard crusts during dry weather if improperly 



managed? 

 o. Which soils will work up into the most perfect seed beds for gardens? 

 (). Why should clay soils, if plowed rather wet, not he allowed to dry l^efore 



harrowing? 

 7. Give other points in the proper management of clod-forming soils. 



