146 SCIENCE AND SOIL 



taining a small proportion of the coarser grades of sand. The subsoil is a 

 heavy brownish yellow loam overlying a fine gravelly loam. It is a bottom 

 land, frequently occurring as terraces. It is generally well drained. It con- 

 sists of glacial drift redeposited by stream action. " 



(1570 Ib. P.) "One of the more fertile soils of the area. Some of the fields, 

 tilled for more than half a century and only moderately manured, still produce 

 abundantly. . . . Corn yields from 40 to 100 bushels per acre, with the aver- 

 age production probably about 75 bushels, and wheat from 20 to 35 bushels 

 per acre." (Report for 1902, page 395.) 



Volusia silt loam (Ohio) "is a gray to brown silty loam with an average 

 depth of 8 inches. The subsoil is a light yellow silty loam, mottled with gray 

 in its lower portions. It has resulted in most part from the glaciation of shales. 

 Its mechanical constituents closely resemble in size those of the soils derived 

 from the loess, being composed largely of silt. This is doubtless due to the silt 

 in the shales from which this soil type comes in large part. " 



(1480 Ib. P.) "The average yield of wheat is about 20 bushels per acre, 

 and yields as high as 30 bushels are not uncommon. Corn, under the best 

 cultural methods, will average 40 to 45 bushels per acre. Oats will yield an 

 average of 50 bushels per acre, although larger yields are often reported. 

 From 100 to 150 bushels of marketable potatoes per acre is the average produc- 

 tion of this crop. " (Report for 1904, page 559.) 



Podunk fine sandy loam (Connecticut) "is an alluvial soil, formed by the 

 reworking by running water of glaciated granites, gneisses, and schists. It 

 contains an abundance of micaceous mineral particles visible to the eye. It is 

 underlain by fine sand. The soil is of a dark brown color and is well drained. 

 The tobacco field from which the sample came had been heavily fertilized for 

 years. " 



(1920 Ib. P.) " The type is entirely under cultivation and produces good 

 crops of corn, late truck, cucumbers for pickling, and tobacco. The area in 

 the latter crop is large, and the yields range from 1700 to 1900 pounds in the 

 open field." (Report for 1903, page 54.) 



RESIDUAL SOILS 



Oswego silt loam (Kansas) "consists of a dark gray silty loam, varying 

 from very shallow to 10 inches deep, which grades into a stiff clay, becoming more 

 impervious with depth. It becomes hard and compact on drying, but it is easily 

 broken up into a mellow loam if plowed when in proper condition of moisture. 

 This is an upland type, and occupies gently rolling prairies. Owing to the 

 topography of the country, the type has good surface drainage. The Oswego 

 silt loam is derived from the weathering of the underlying rock, this usually 

 being shales, with occasional interbedded layers of sandstone and limestone. 



(1050 Ib. P.) "The Oswego silt loam is not a strong soil It is 



better adapted to wheat than to any of the other crops grown in the area, but, 

 even with wheat, commercial fertilizer costing about $1.25 an acre is used on 



