Soils and Soil Management 



59 



torn. Observe the different layers. The coarse material at the bot- 

 tom is probably sand. Above this will be a layer of finer particles 

 consisting largely of clay, the finest particles of which remain in 

 suspension in the water, making it turbid. Small particles of vege- 

 table matter may be found floating on the surface. 



Estimate the amount of sand and clay in the samples. What 

 effect did working the soil into a paste have on the size of the granules? 



Make similar tests with a number of different kinds of soils. 

 Make a table as shown below, and record your observation for each 

 sample of soil. 



93c. Classify the soils examined according to the following 

 scheme. Estimate the amounts of the sand or clay. 



93d. Weight of a Cubic Foot of Soil. It will not be necessary to 

 use a full cubic foot. Small, rectangular boxes may be made and 

 then carefully measured for their inside dimensions. The dirt 

 may be put in these and weighed, and the results calculated to a 

 cubic foot. Three-pound tomato cans, with the tops melted off, 

 may be used in the same way. The samples of soils should be 

 thoroughly dry and free from coarse lumps. Weighing should be 

 very carefully made and recorded. A sample of every type of soils 

 in the community should be used. 



94. Temperature of Soils. Soils have the power of 

 absorbing the heat from the sun's rays. If they absorb 

 the heat readily they are called warm soils, and if slowly, 

 cold soils. Dry soils get warm much more quickly than 

 moist soils. Barefooted boys know that the dry sands 

 and fine clay road dust becomes warm more quickly 

 than moist soils. 



