10 
BULLETIN 143, U. S. DEPARTMENT OF AGRICULTURE. 
contain a high percentage of flat fragments of shale and sandstone, ranging 
from 1 or 2 inches to a foot or more wide. In addition, a considerable quantity 
of finely divided shale fragments is found in both soil and subsoil. The subsoil 
usually rests at varying depths below 18 inches on beds of shale or sandstone 
rock. The type is derived from the weathered products of the shale and sand- 
stone, reworked by glaciation and slightly modified by extraneous glacial ma- 
terial. It occupies rolling and hilly land and is frequently interrupted or 
bordered by steep slopes not suited to agricultural purposes. The Volusia silt 
loam where properly cultivated is a good soil for timothy and small grains. In 
the eastern part of the region where it occurs it lies at too high an elevation to 
be well adapted to corn. In this region buckwheat and potatoes are grown to 
advantage. 
Each of the above soils was treated with applications of the slag 
fertilizer, and wheat seedlings were planted. The plants were grown 
for a period of three weeks and then weighed and compared with 
those grown under similar conditions in untreated soil and in soil 
treated with other forms of potash and phosphatic fertilizers. Since 
the Volusia silt loam responds readily to treatment with lime, two 
sets of experiments were run with this soil. In the first no lime was 
used except that furnished by this slag fertilizer, but in the second 
set of tests the soil was limed at the rate of 2 tons to the acre. This 
was done in order to make sure that any beneficial effect observed 
from the slag treatment was not entirely due to the basic character 
of this material. 
In Tables VI, VII, VIII, and IX the results of these experiments 
are given. The weight of the untreated plants, or checks, is taken 
as 100 ; and the weights of the plants grown under similar conditions, 
but in soils treated with various potash and phosphatic fertilizers, 
are compared with this figure. 
Table VI. — Relative green weights of wheat plants grown for a period of three 
weeks in Carrington silt loam untreated and treated with various quantities 
of potassic and phosphatic fertilizers. 
Application per acre. 
Relative 
green 
weights. 
Average. 
Treatment. 
K 2 0. 
P2O5. 
Checl' 
Pounds. 
Pounds. 
100 
101 
104 
107 
100 
113 
106 
101 
107 
114 
no 
no 
108 
100 
SIa CT (33SB ) 
50 
100 
200 
50 
100 
200 
60 
120 
240 
1 
Do . 
\ 104 
Do 
j 
Do 
1 106 
Do 
60 
120 
240 
60 
120 
240 
j 
Do 
\ 107 
Do 
50 
100 
200 
) 
Do 
\ 109 
Do - 
J 
