l6 THE PHYSICAL PROPERTIES OF SOILS 



Determine the hygroscopic moisture remaining in 

 the air-dry samples, and calculate the moisture auitent 

 of the field samples as follows : 



( 1 ) As per cent of the dry weight of the soil. 



(2) As pounds per cubic foot. 



(3) As surface inches, the total amount to the depth 

 of three feet. 



Tabulate the results and compare the moisture con- 

 tent of the soils under the different crop conditions. 

 Discuss the reasons for the observed differences. 



References : 



Burkett, "Soils," Chapter IV. 

 Hall, "The Soil," p. 132. 

 Bulletin No. 4, Bureau of Soils, pp. 22-24. 

 Stevenson & Schaub, "Soil Physics Laboratory 

 Guide," pp. 1-7. 



