68 
SOIL SURVEY OF WAUPACA COUNTY. 
Probably the most important factor in determining the value 
of marsh land will be the crops which can be grown upon it. 
This depends upon two factors, first the degree of drainage, and 
second the danger from frosts. When only the main outlet and 
lateral ditches have been installed, in the great majority of 
cases, hay crops are the only ones which can be safely grown, 
and the character of the hay will also depend a good deal on 
the character of the drainage. In the case of peat land under¬ 
lain by sand, the drainage by well constructed and sufficiently 
deep ditches 40 to 80 rods apart will, in some cases give ade¬ 
quate drainage for hay. When the peat is underlain by silt 
or clay, however, ditches not more than 20 rods apart will be 
necessary ,and these must lower the water in the ditch to a 
point 4 or 5 feet below the surface during part of the grow¬ 
ing season. When tilled crops are grown, such as corn, cab¬ 
bage, or potatoes, or small grains are to be grown the drainage 
must be more certain, and over the larger proportion of the 
marsh land this will mean the installation of drainage systems 
in the form of either open lateral ditches or of tile not more 
than 10 and often not more than 5 rods apart on the average. 
Tile drainage is the more satisfactory. The cost of tile drain¬ 
age will vary from $40—$80 per acre after the main outlets 
have been put in. 
It is well known that frosts frequently occur on marsh land 
when there is no frost at all on the higher land adjoining. 
This is partly because the cold air which forms on the surface 
of all the ground at night tends to flow down and collect jn 
low places, but it is also the result of the fact that the loose, 
spongy soil of peat marshes does not conduct the heat received 
from the sun during the day downward to so great an extent 
as do upland earthy soils. In consequence of this, the lower 
layers of soil do not become warmed in peat marshes as they do 
in other earthy soils and the little heat left in the surface inch 
or two is rapidly lost at night by radiation, so that he freezing 
point is frequently reached on such soil when it would not be 
on more earthy soils such as sandy loam or clay loams which 
would conduct the heat downward better during the day, and 
so keep warm farther into the night. 
I his difficulty with peat marshes can be overcome to a cer¬ 
tain extent by heavy rolling which, by compacting the soil, per¬ 
mits the heat to be conducted downward more readily. It will 
also to a certain extent become less in time as the peat decom- ] 
