Dec. 24,1917 Decomposition of Green and Stable Manures in Soil 683 
organic matter of the soil was the same as where no organic matter was 
added. Hence, the value found for soils number 5 and 6 in column 9 
was obtained by subtracting the value for 1 and 2 from 5 and 6, in column 
7. To obtain the number for 7 and 8 in column 9, the value for soils 3 
and 4 was subtracted from 7 and 8 in column 7. Columns 10 and 11 are 
self-explanatory. To obtain the values found in column 12, it was assumed 
that where stable and green manure were used in the soil in combination 
the stable manure and soil organic matter lost as much carbon as where 
the stable manure alone was added to the soil. 
Table III .—Summarized data of Experiment I 
[Unless otherwise given, results are expressed as pounds of carbon per acre] 
Soil No. 
Or¬ 
ganic 
carbon 
added. 
Total 
organic 
carbon 
at start. 
Inor¬ 
ganic 
carbon 
added. 
Total 
carbon 
lost. 
Inor¬ 
ganic 
carbon 
at end. 
Or¬ 
ganic 
carbon 
lost. 
Excess 
organic 
carbon 
lost 
from 
limed 
over 
un¬ 
limed 
soil. 
Or¬ 
ganic 
carbon 
from 
added 
ma¬ 
nure. 
Car¬ 
bon 
lost 
from 
added 
ma¬ 
nure. 
Total 
organic 
carbon 
lost. 
Or¬ 
ganic 
carbon 
from 
green 
ma¬ 
nure 
alone. 
Quan¬ 
tity of 
cal¬ 
cium 
car¬ 
bonate 
at end 
in 
limed 
soils. 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
x 3 
i, 2. 
None. 
None. 
7? 500 
7 ; soo 
861 
861 
8,361 
8,361 
898 
898 
8,398 
8,398 
29 , 5*3 
29,513 
37,013 
37,013 
30,374 
30,374 
37 ,874 
37 ,874 
30 , 4 H 
30 ,411 
37 , 9 H 
37 , 9 H 
770 
1,393 
1,071 
1,625 
1,188 
1,798 
1,484 
2,138 
1,306 
1, 896 
1,560 
2, 196 
27 
218 
44 
271 
31 
270 
71 
283 
36 
274 
69 
310 
797 
93 i 
i,U 5 
1,216 
1,219 
1,388 
1, 555 
l, 74 i 
1,342 
1,490 
1,629 
1, 826 
Per ct. 
Per ct, 
2.70 
3 - i 5 
3.02 
3* 28 
4.01 
4 - 57 
4.10 
5- 10 
4.41 
4. 89 
4. 29 
4.82 
Lbs. 
3. 4 . 
S, 6. 
680 
134 
318 
285 
422 
457 
758 
810 
545 
559 
832 
895 
4 - 23 
3.80 
49.00 
53 -io 
9.07 
9.70 
60.80 
62.30 
9.91 
10. 70 
1,818 
7,8. 
9, IO . 
680 
101 
2,260 
II, 12 . 
13, 14 . 
1$, 16... 
17, 18. 
680 
680 
169 
186 
440 
525 
2,250 
2,360 
19, 20. 
21, 22. 
23 , 24 . 
680 
680 
148 
197 
515 
610 
2,280 
2,580 
DISCUSSION OF RESULTS 
The number of pounds of organic carbon at the end of the experiment 
(shown in column 6 of Table III) are worthy of study. These results 
will be considered with those for the number of pounds of residual calcium 
carbonate. It is observed that in every case the organic manures acted 
as conservers of lime. As to why that is, it is difficult to understand. 
One would think that the acids formed by the decomposition of the 
manure would decompose the lime. Perhaps this takes place in the 
early stages, and then these calcium salts of the acids are in turn acted 
on by the microorganisms with the re-formation of calcium carbonate. 
In this connection the work of Gimingham ( 2) may be pertinent. He 
stated that the soil organisms changed the calcium salts of such organic 
acids as oxalic found in plant tissues to calcium carbonate. This can 
hardly account for all of the excess carbonate in the green-manured soils, 
as the following considerations will show. According to data appearing 
in Hopkins's Soil Fertility and Permanent Agriculture (3, p . 60s) 1 ton 
