GROUP OF HEAVY SOILS. 
19 
CHAPTER II 
GROUP OP HEAVY SOILS 
KNOX SILT LOAM 
Extent and distribution .—The Knox silt loam all lies west 
of the Black River. This is an important and extensive type 
of soil in Jackson County, the towns of Melrose, Franklin, Gar¬ 
den Valley, Albion, Irving, Currian, and Northfield being made 
up largely of it. 
Description .—The surface soil of the Knox silt loam consists 
of twelve inches of a grayish-brown or buff-colored silt loam, 
having a friable structure and a smooth feel. While there is 
present a small percentage of fine and very fine sand, but few 
coarser grains are found. The lower portion of the soil usually 
is of a yellowish color, but on drying, the surface becomes ashen 
in appearance. As a whole, the texture of the material is very 
uniform, but varies somewhat in depth. The subsoil consists 
of a heavy, yellow silt loam, grading into a silty clay loam at 
eighteen to twenty inches, and usually becoming a light clioco- 
ate brown color at thirty to thirty-six inches. It is compact, 
and is uniform throughout its entire extent, except as indicated 
in the phase described below. The underlying rock lies from 
four to ten or more feet below the surface. 
The most important variation in this soil has been designated 
as the steep phase on account of its steep slopes and rough, un¬ 
even topography. This phase is described in greater detail 
following the description of the typical soil. 
Minor variations in the typical soil occur, chiefly on the nar¬ 
row ridges, where the surface soil has in places been removed 
and the heavy subsoil exposed. In such places the depth to 
the underlying rock is also less than over the more extensive 
areas of this soil, and in some instances it can be reached with 
a three-foot auger. On some of the lower slopes, the wash from 
the adjoining higher land has accumulated to a small extent, 
