30 



FIELD OPERATIONS OF THE BUREAU OF SOILS, 1918. 



turally, as almost all of it is in cultivation. Like the Grundy silt 

 loam, it is essentially a corn soil. Other principal crops are oats, 

 hay, and wheat. Corn 3'ields 30 to 70 bushels, averaging 40 bushels, 

 per acre; oats, 30 to 70 bushels, averaging 45 bushels; hay, three- 

 fourths ton to If tons, averaging 1| tons; winter wheat, 15 to 42 

 bushels, averaging 26 bushels; spring wheat, 10 to 40 bushels, aver- 

 aging 23 bushels; and rye, 10 to 25 bushels, averaging 15 bushels. 

 No special industry is engaged in on this type. 



This land ranges in price from SI 35 to S250 an acre, with an 

 average of about $165 an acre. 



The following table gives the results of mechanical analyses of 

 samples of the soil and subsoil of the Tama silt loam: 



Mechanical analyses of Tama silt loam. 



KNOX PINE SAND. 



The typical Knox fine sand is a brown fine sand throughout the 

 3-foot section. There is no sharp line of distinction between surface 

 soil and subsoil, but a slightly yellowish cast appears with depth. 



This soil includes a greater range in variation than any other in the 

 county. In some places the surface soil is distinctly grayish brown 

 when dry. The type includes small patches where the surface texture 

 is a medium sand, while in other places the surface texture may be a 

 very fine sand, or may approximate closely a loam. In these latter 

 variations the subsoil is usually of the same texture as the surface soil, 

 and yellowish to yellowish brown in color. The type is supposed to be 

 derived from material blown up by the wind to its present position. 



This type is confined to rather narrow ridges along the western 

 edge of the eastern upland with the exception of a small area lying 

 partly in sec. 4 and partly in sec. 9, T. 75 N., R. 4 W., on the crest of 

 a broad ridge projecting above the general elevation of the rest of 

 the upland and lying 3 V miles back from the edge of the upland. The 

 type is most typically developed 2 miles directly north of Wapello, 

 The area 1 mile northwest of the one just mentioned has a more 

 grayish color, and the soil seems to be shifted about by the wind at 

 the present time. The same is true of a considerable part of the 

 two areas in the vicinity of Sandy Grove School northeast of Fredonia. 

 The area If miles east of Wapello occupies a ridge and is a very fine 

 sand in texture. 



