260 
Journal of Agricultural Research 
Vol. IX, No. 8 
Organic solvents obtained from these thoroughly decomposed sub¬ 
stances were made by shaking up an equivalent of 33 gm. of dry material 
in 500 c. c. of distilled water, and filtering through Chamberland filters. 
These organic solvents were then used for making soil extracts in the pro¬ 
portion of 500 c. c. of the solvent to 250 gm. of soil. These soil extracts 
were filtered through Chamberland filters and analyzed (Table VI). The 
results given in Table VI show that in most instances the organic sol¬ 
vents obtained from the completely decomposed green manures were not 
as active in breaking up the soil minerals as the organic solvents from 
the same materials in the first stages of decomposition (see Table III). 
Table VI .—Soil minerals removed by extracting soils with organic solvents from com - 
pletely decomposed artificial manures 
(Results expressed as parts per million of dry soil. Amounts removed by distilled water have been 
deducted] 
Organic 
substance. 
Added to soil with or¬ 
ganic extracts. 
Clay-loam soil. 
Sandy-loam soil. 
Iron. 
Cal¬ 
cium. 
Magne¬ 
sium. 
Phos¬ 
phoric 
acid. 
Iron. 
Cal¬ 
cium. 
Magne¬ 
sium. 
Phos¬ 
phoric 
acid. 
Iron. 
Cal¬ 
cium. 
Magne¬ 
sium. 
Phos¬ 
phoric 
acid. 
Barley hay. 
0. 25 
104 
94 
81 
0. 6$ 
30S 
92 
43 
1.69 
205 
68 
91 
S w e e t-clover 
hay. 
3. 70 
116 
140 
105 
1.89 
472 
196 
77 
3 * 3 2 
292 
146 
79 
Alfalfa hay. 
3.20 
7 i 
88 
no 
1.62 
411 
149 
30 
1.41 
246 
93 
77 
Cow manure... 
. 18 
89 
120 
98 
.18 
290 
116 
83 
.09 
221 
97 
64 
Bean straw. 
.98 
834 
247 
82 
.05 
758 
38s 
3 i 
1.83 
670 
315 
55 
The organic extracts of the completely decomposed green manures 
were neither acid to methyl orange nor alkaline to phenolphthalein, but 
required a considerable amount of acid to develop an acid reaction, 
with methyl orange as an indicator (Table VII). 
Table VII .—Quantity {in cubic centimeters) of normal hydrochloric acid required to 
develop an acid reaction in 100 c. c. of extract from completely decomposed green 
manures before and after extracting soils t using methyl orange as an indicator 
Organic 
extract. 
After extracting. 
Source of extract. 
Clay-loam 
soil. 
Sandy-loam 
soil. 
Barley manure. 
C. c. 
2. O 
C. c. 
J a ) 
Trace. 
C. c. 
I. 6 
Sweet-clover manure. 
(0) 
Trace. 
Alfalfa manure. 
7. 2 
7 . 3 
Cow manure. 
1 6 
1. 6 
0 0 
1. 6 
Bean-straw manure. 
5-8 
4.8 
5 - 1 
« Not determined. 
