Dec. 24,1917 Decomposition of Green and Stable Manures in Soil 679 
2.5-liter acid bottles. This diminished chances for leaks. The treat¬ 
ment of the soils, in tons per acre, was as follows: 
Pot No. Treatment. 
I, 2. Control. 
3, 4.3 tons of calcium carbonate. 
5, 6. 10 tons of manure. 
7, 8. 10 tons of manure and 3 tons of calcium carbonate. 
9, 10. 1 ton of oats. 
II, 12.... 1 ton of oats and 3 tons of calcium carbonate. 
13, 14.... 1 ton of oats and 10 tons of manure. 
15,16.... 1 ton of oats, 10 tons of manure, and 3 tons of calcium carbonate. 
17, 18.... 1 ton of clover. 
19, 20.... 1 ton of clover and 3 tons of calcium carbonate. 
21, 22.... 1 ton of clover and 10 tons of manure. 
23, 24.... 1 ton of clover, 10 tons of manure, and 3 tons of calcium car¬ 
bonate. 
The manure used was well-rotted horse manure, air-dried and coarsely 
ground. The oats and clover were about two-thirds mature tops, 
air-dried and ground rather fine. The weights as given above refer to 
air-dried weights in all cases. Two and one-half pounds of soil were 
mixed with their respective treatments and then placed in the acid 
bottles. These were then connected with the apparatus which was freed 
from carbon dioxid. The soils were all made up to 22 per cent of moisture. 
This was done by adding 250 c. c. of “water" to each bottle. In every 
case 100 c. c. of this “water" were made up of an emulsion made from 
fresh soil; and, in the case of those soils receiving stable manure, 100 c. c. 
of fresh-manure emulsion were included in the 250 c. c. of “water." The 
soils, manures, and calcium carbonate were analyzed for total carbon at 
the beginning of the experiment. The experiment ran from July 10 to 
September 2, 1915, a total of 53 days. 
At the end of the experiment all the soils were analyzed for carbonate 
carbon. Throughout the course of the experiment the carbon dioxid 
evolved was determined from time to time. In Table I will be found the 
total amount of carbon evolved from the soil as carbon dioxid, calculated 
in pounds per acre of 2,000,000 pounds. It will be observed that in 
general the duplicates agree very well. It may be stated that for each 
period the duplicates* checked on the average about as closely as the 
summed-up amounts indicate. To put all the determinations which 
were made into a table would take up more space than we care to use here. 
Tabi^E I .—Amount of carbon evolved as carbon dioxid from soils in Experiment I 
[Results expressed as pounds of carbon per acre] 
Soil No. 
Original. 
Duplicate. 
1,2. 
771.9 
767.7 
3,4 . 
392 . 5 
i> 393 - 3 
5,6 . 
1,070. X 
i, 071. 8 
1,625. 5 
7.8. 
i. 625. 5 
9 ,10. 
1, iS 3 - 8 
1, 223. 0 
11,12. 
I, 794 . I 
1,802. 3 
Soil No. 
Original. 
Duplicate. 
13,14 . 
I, 490. I 
1 , 477 -S 
IS. 16 . 
2, 153 - O 
2, 123.3 
17.18. 
1,309. 6 
x, 883. 1 
I, 304. 2 
20 . 
1, 909. 8 
21, 22 . 
1. 567- 7 
I. SSI- 8 
23 ; 24 . 
2, l88. O 
2, 204. 9 
