18           BUREAU OF .CHEMISTRY AND SOILS, 1926

acreage of this crop is increasing. The rotation most commonly
followed is corn, small grain for one or two years, followed by hay
for one or two years, after which the land is put back into corn.
  Bellefontaine silt loam, level phase.-A number of level or gently
undulating areas of Bellefontaine silt loam were mapped as the level
phase of this soil. The soil is similar to the typical soil, but the
surface layer is a little deeper and may contain somewhat more
organic matter. The agriculture is similar to that on typical Belle-
fontaine silt loam.
  A number of imperfectly drained areas, included with Bellefon-
taine silt loam, level phase, have a surface soil of gray heavy silt
loam 8 inches thick, a subsurface layer 4 or 5 inches thick of brown-
ish-yellow silt loam, and a subsoil of mottled gray and yellow friable
silty clay containing a trace of gravel to a depth of 40 or more
inches.
  Bellefontaine silt loam, rolling phase.-The rolling phase of Belle-
fontaine silt loam was separated from the typical soil entirely on
the basis of surface relief. It includes areas having a slope sufficient
to make them susceptible to erosion and to interfere with the use
of ordinary farm machinery. The slopes range from gentle to steep ;
areas having a slope greater than 15' were mapped as rough broken
land. The soil of the rolling phase is the same as that of typical
Bellefontaine silt loam, except that it is more stony.
  This rolling soil is most common on the steep slopes bordering
streams, but some areas are found on morainic hillsides. Drainage
is excessive. Probably 25 per cent of the land is cleared and culti-
vated; the rest is in woods and permanent pasture.
  Less corn and more hay and pasture crops are grown on this than
on the typical soil. The average yields are about the same. Com-
paratively, more alfalfa is grown than on any other soil in the
county. Alfalfa does particularly well because of the good drainage
and calcareous subsoil, and it prevents the soil from washing. This
rolling soil is used with other soils for dairy farming.
                        BELl"FONTAINE LOAM
  The surface soil of Bellefontaine loam to a de.pth of 3 or 4 inches
is dark grayish-brown loam containing considerable organic matter.
This is underlain to a depth of 9 inches by yellowish-brown loam of
somewhat laminated structure, beneath which, to a depth of 17
inches, is yellowish-brown sandy loam with a small content of gravel
and some iron stains. Between depths of 17 and 22 inches the ma-
terial is reddish-brown sandy clay loam, and between 22 and 27
inches it is gravelly, gritty material containing some clay. Below
27 inches is the unassorted gravelly glacial till.
  This is a rather extensive soil, occurring mostly in the southwest
and north-central parts of the county in association with Bellefon-
taine silt loam. Tracts range from nearly level to gently rolling and
even rolling in places. Because of the surface features and open-
ness of the subsoil, natural drainage is good. Practically none of
this soil requires tile drains.
  The parent material of this soil is made up of glacial dsbris com-
posed of dolomitic limestone and mixed with other material carried