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A YEAR IN AGRICULTURE 



(c) Secure a third sample from a depth of twelve inches 

 from the surface. 



Return to the laboratory and weigh out four ounces of 

 each sample of soil. Spread each sample in a shallow pan 

 and allow to dry for two or more days. Weigh each sample 

 again. The difference between these weights and the first 

 ones is the amount of water in the soils removed by evapora- 

 tion. Note the color of each sample of soil. Examine with 

 hand lens to see the size of soil particles. Heat each sample 

 in an iron spoon until everything that will burn has been 

 burned, and weigh each sample again. The difference between 

 these weights and the last ones shows approximately the 

 amount of organic matter in each. The last weights show 

 the amounts of mineral matter in the soil samples. Tabulate 

 the results as follows: 



Repeat this exercise with samples from different fields. 



3. Physical examination of soil particles. Pulverize air- 

 dry samples of sand, loam, clay, and gravel. Place a few 

 grains of each sample of soil on a white paper and examine 

 with hand lens. Tabulate your observations as follows: 



