52 BULLETIN 140, U. S. DEPARTMENT OF AGRICULTURE. 



If most of the sand is fine, rather than medium or coarse, the type 

 is a fine sandy loam. When still more of the clay and silt are 

 included, so that the proportions of sand and fine material are about 

 equal, thus obscuring largely the grittiness of the sand, the soil is 

 a loam. 



When the clay and silt particles predominate only the fine grades 

 of sand are usually present. If the silt grade is most abundant the 

 soil is a silt loam. If clay is greatest in amount, the soil is a clay 

 loam. And if the exceedingly fine clay particles constitute more than 

 30 per cent of the soil mass, the type is a clay, the other 70 per cent 

 being primarily of silt and very fine sand. A soil containing as much 

 as 50 per cent clay is very " heavy," while those containing 60 to 70 

 per cent, as along Lake Superior and Lake Champlain, are exceed- 

 ingly stiff and hard to work. 



The classification in the above table refers to surface soils. Where 

 surface soils differ materially in color, as red and yellow, even though 

 derived from similar geological materials, as the Wethersfield and 

 the Middlefielcl soils, they are placed in different series. If two 

 identical surface soils are underlain by subsoils, one of a sandy 

 nature and the other clayey, they also are, or should be, placed in 

 different series, as the light and heavy subsoils of the Gloucester 

 series. If two soils and subsoils are identical in texture and color, 

 but differ in the character of the geological material from which 

 they are derived, as limestone and granite, they are placed in dif- 

 ferent series, to wit, the Dover and the Gloucester series. These 

 distinctions all lie within a given soil province such as New England, 

 or the Atlantic Coastal Plain, the Appalachian Mountains and 

 valleys, etc., but on account of differences in climatic and consequent 

 cropping characteristics the same series name is not used in two 

 soil provinces, even though the soils are similar in color and deriva- 

 tion. This is illustrated in the Southern States by the Cecil and the 

 Porters soils, the former occurring in the Piedmont Plateau and the 

 latter in the Appalachian Mountains division. 



In the Gloucester series loams and fine sandy loams are the pre- 

 dominating soil types in Massachusetts and Connecticut. Fine sand 

 is next in importance, and on Cape Cod it is the most prevalent type. 

 True clays and heavy clay loams do not occur. Even light clay loams 

 are uncommon, heavy loams and silty loams constituting the heavy 

 soils of the region. In the Wethersfield and Middlefield series the 

 silt loams and the fine sandy loams are the most important types, 

 though there is considerable loam and a little sandy clay. 



SOILS FAVORABLE FOR THE BALDWIN. 



If soils are thought of as grading from heavy to light, corres- 

 ponding to the range from clay to sand, then soils grading from 



