MORE ABOUT SOIL TYPES 25 



More About Soil Types. — It is to be observed that a type name 

 is usually made up of the name of a soil class added to a name 

 which indicates its general characteristics, aside from texture, 

 and which determines the series to which it belongs, as : 



Dunkirk sandy loam 

 (series) (soil class) 



Knox silt loam, Cecil loam, Dekalb silt loam, Hagerstown 

 loam, Genesee loam, Bozeman silt loam, Gila silt loam and Salt 

 Lake loam are eight types representing as many series. Though 

 these types are widely scattered throughout the United States, yet 

 they may be grouped into two classes; viz., loam and silt loam. 



It is possible to have two types differing from each other in 

 several distinct ways, or in just one respect. 



Peat and muck are two special types of soils. 



Peat may be defined as a soil type consisting of from 50 to 

 95 per cent organic matter (p- 16). 



Muck may be defined as a type of soil which consists of from 

 15 to 50 per cent of well-decomposed organic matter and 50 to 

 85 per cent mineral matter. The mineral matter in muck consists 

 of sand, silt and clay particles deposited by water or wind during 

 its formation. 



Meadow may also be considered a special, or miscellaneous, 

 type of soil, meaning first bottom land which is low, poorly drained, 

 and subject to overflow. The texture is so variable that no sepa- 

 ration into established types can be made. 



It is possible on some large farms to map a dozen or more 

 types which may be grouped into three or more series. 



Within a single state more than a hundred .types of soils have 

 been mapped — ^in Wisconsin, for example, more than 125 types 

 grouped into more than 30 series. 



In the United States there have been mapped thus far more 

 than 2900 types classified in more than 740 series (Fig. 13). 



Blustration Material for Lessons. — 1. Two or three samples of soil — 

 natural and with organic matter burned out. Note loss of weight, change of 

 color and any other changes. 



2. Samples of various colored soils — ^include some subsoils. Why do soils 

 vary in color? 



3. Glacial pebbles and any other material showing glacial action. 



4. A son map to show how soils are mapped. 



5. Three or more types of soil belon^g to the same series to Illustrate 

 soil classification according to type. 



6. A state map to illustrate land description — ^township, range, section, etc. 



