EXERCISE 12 



COLLECTING SOIL SAMPLES 



Statement. Scarcely any other material appears to be of so little interest or importance as the soil 

 which we thoughtlessly tread under our feet, yet it is the source of more wealth than all other materials 

 in the world combined. More than twice as much wealth is obtained from the soils of the United 

 States in a year as has been taken from the gold and silver mines of the United States in all the years 

 since Columbus discovered America. The origin, the depth, and the texture of a soil determine largely 



the kind of crops it will produce and how 

 long it will remain productive. 



Object. To procure samples of different 

 types and grades of soils and subsoils for 

 study and comparison, and to study, in the 

 field, the texture and color of soils in rela- 

 tion to their agricultural value. 



Materials. Soil auger, ruler, a dozen or 

 more one-quart mason jars, a piece of oil- 

 cloth about 12 by 15 inches, and labels. 



Directions. Sample the most productive 

 and least productive soils of the neighbor- 

 hood, including those from bottom land, 

 upland, and the hillsides. 



To obtain a sample remove the vegetation 

 and other rubbish from the spot where the sam- 

 ple is to be drawn. Bore to a depth of 7 inches 

 with the auger. Pack the surface around the 

 auger with the foot and withdraw the auger. 



Fig. 16. Method of taking soil samples 



Place the sample on the oilcloth, examine it as suggested below, and when the examination is finished, pour 

 the sample into a Mason jar. Seal the jar and label it, "No. 1 — Surface Soil." Insert the auger in the 

 same hole and remove the soil to the beginning of the subsoil. Place this soil in another jar ; seal it and 

 label, "No. 2 — Sub-surface Soil." Take a third sample, going into the subsoil about 12 inches, and label 

 it, "No. 3 — Subsoil." The fourth sample should be taken to a depth of about 28 inches or 36 inches and 

 be labeled, "No. 4 — Subsoil." The sealed samples are to be taken to the laboratory for examination of soil 

 texture, structure, and composition. While taking the samples, observe changes in color and the depth at 

 which they occur. Observe the apparent changes in the moisture present at different depths. Note the "feel" 

 of the soil at different depths, that is, whether it feels coarse or gritty, or powdery and smooth, when rubbed 

 between the thumb and fingers. Note changes in the stickiness, hardness, porosity, and density of the soil at 

 each depth. Discuss the results of your observations and their practical application to soil values. 



Questions. Which of the soils sampled are fine? Which medium? Which coarse? Which has the 

 finer texture, the soil or the subsoil ? Why ? What inferences do you draw from the variations in the 

 color of soils ? What are the common colors of soils ? What color of soil and subsoil do you regard as 

 indicative of a productive soil ? 



References. Waters, H. J. Essentials of Agriculture, pp. 58-64. Ginn and Company. Mosier and 

 Gustafson. Soil Physics and Management, pp. 116-123. J. B. Lippincott Company. Hall, A. D. The 

 Soil, pp. 47-50. E. P. Dutton and Company. 



Note. As much as two or three bushels each of washed sand, rich garden loam, and stiff clay should be secured 

 and stored in bins for use in later experiments in crop growth and soil management. 



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