26 
SOIL SURVEY OF WAUPACA COUNTY. 
tent of organic matter is somewhat below the average of soils 
of this texture. In regard to lime they vary within very wide 
limits, in some sections being acid, while in others they contain 
as high as 10 to 12 per cent of lime carbonate. 
Phosphorus .—The comparatively small total amount of phos¬ 
phorus contained in these soils together with the relatively large 
amount of iron oxide renders this element somewhat unavail¬ 
able to growing crops and makes it important that farmers oper¬ 
ating on this type of soil see to it that the available supplies of 
this element are maintained or increased either through the use 
of feeding stuffs high in this element or the purchase of suffi¬ 
cient phosphate fertilizers. Experiments on this soil at Ash¬ 
land showed a large increase through the use of phosphate fer¬ 
tilizers in addition to manure. The following table gives the 
results of some of these experiments. 
EHj Crop 
10 tons manure only 
10 tons manure and 
1000 lbs. rock 
phosphate 
Per cent of increase 
Potatoes. 
87 
bu. per A 
128 lEbu. 
47 
Rutabagas. 
108 
bu. per A 
137 
bu. 
27 
Corn. 
30.4 
bu. per A 
36.8 
bu. 
21 
Clover hay. 
2223 
pounds 
3177 
pounds 
43 
Clover seed. 
217.5 
pounds 
336.7 
pounds 
47 
The importance of having sufficient supplies of this element 
is made still greater by the relatively poor drainage which the 
Superior clay loam has and its consequent tendency to be cold 
so that crops are slow in maturing. The element phosphorus is 
particularly helpful in hastening the maturity of crops and the 
formation of seed. 
Potassium .—These soils average over 50,000 pounds of this ele¬ 
ment per acre to a depth of 8 inches. This potassium, however, 
in the form in which it exists in the soil is not available to crops 
and becomes so only as a result of chemical changes which are 
chiefly brought about through the action of organic matter. 
\\ hen a good supply of active organic matter is maintained the 
quantity of potassium is sufficient to supply growing crops al¬ 
most indefinitely and it is only in the case of fields low in or¬ 
ganic matter or where crops using unusually large amounts of 
