38 BULLETIN 142, U. S. DEPABTMENT OP AGRICULTURE. 
becomes more compact and claylike. The lower part of the 3-foot 
section is usually a brownish clay or clay loam containing consider- 
able sand and gravel. At greater depths the material becomes dis- 
tinctly gravelly and sandy, and numerous bowlders are encoun- 
tered. The flat phase grades into the Clyde silty clay loam in 
depressions where there has been a considerable accumulation of 
organic matter, and into the normal or rolling phase of the Miami silt 
loam where the topography becomes somewhat more rolling and 
the covering of silt over the underlying sandy and stony clay is of 
less depth. This phase of the type is practically stone free at the 
surface. 
The surface of practically all of this phase is only ver}^ gently un- 
dulating, while considerable tracts are nearly level. Some small 
areas of low relief are found within the phase. The depressed and 
nearly level areas are usually rather poorly drained, and only the 
more elevated areas lying along the crests of low swells have fair 
to good natural drainage. The greater part of the phase would be 
materially benefited by the installation of tile underdrainage. 
The flat phase of the Miami silt loam originally supported a mixed 
growth of hardwood timber in which beech predominated. It came 
to be known as "beech land," in distinction from the more rolling 
phase of this type, which was known as " sugar-tree land " because of 
the greater abundance of sugar maple. With the exception of small 
woodlots, the phase has been cleared, and probably 90 per cent of its 
area is under cultivation. 
Corn is extensively grown, giving yields which average somewhat 
below 40 bushels per acre. During exceptionally wet years the yield 
is far below this, and extreme drought also exerts a very unfavor- 
able influence upon the yield. This phase is not so well suited to 
corn production as the more rolling part of the type, and the yields 
are frequently below the average for the region. 
Wheat is commonly grown and constitutes the chief small-grain 
crop on this phase of the type. The yields range from 12 to 20 
bushels per acre, with an average of about 15 bushels. Oats are 
also grown, and in years of abundant rainfall give excellent results. 
The yields range from 30 to 50 bushels per acre, with an average 
of approximately 35 bushels. 
Timothy and clover constitute the chief hay crops. Timothy is 
well suited to this soil, while red clover is not so successfully grown 
as on the more rolling phase. 
Tomatoes for canning are grown to some extent, and potatoes and 
garden vegetables are produced for home consumption. 
Deep phase. — The deep phase of the Miami silt loam has been 
mapped extensively in south-central Wisconsin, where it occurs in 
Dane, Columbia, and Fond du Lac Counties. 
