222 
Journal of Agricultural Research 
Vol. XI, No. s 
The location of these samples is indicated in the case of ring 2 in figure 13. 
The results are shown in Table XIII. In these determinations the first 
figure indicates results on the comparatively fresh soil.; the second figure 
is a determinatian made on a duplicate sample which had remained in a 
dry condition in the laboratory for about seven months. Nitrates were 
least abundant on the inside of the ring and most abundant in the part 
occupied by the old dying mycelium. In the area occupied by the 
young mycelium and just below it, and also in the mass containing the 
dense portion of the mycelium, the nitrate content was about uniform. 
Ammonia was least abundant inside the ring, and most abundant in the 
dense portion of the mycelium. In the case of the new mycelium and 
the area just below the dense mycelium the ammonia content was about 
the same. More ammonia was found outside in the native sod than on 
the inside of the ring. The total nitrogen was determined in duplicate 
from dried samples. It is evident that the changes in the quantity of 
nitrates or ammonia recorded in different portions of the soil mass are 
not accompanied by changes in the total nitrogen content of the soil. 
In other words, the nitrogen seems only to be changed from one form 
to another. 
Table X .—Quantity (in parts per million) of ammonia and nitrates in Agaricus tabularis 
rings , Akron , Colo., 1915 
Ring No. and date. 
Depth. 
Nitrogen in the form of 
ammonia. 
Nitrogen in the form of 
nitrates. 
Out¬ 
side 
zone 
No. 5. 
Bare 
zone 
No. 3. 
Inner 
stimu¬ 
lated 
zone 
No. 2. 
Out¬ 
side 
zone 
No. 5. 
Bare 
zone 
No. 2. 
Inner 
stimu¬ 
lated 
zone 
No. a. 
Feet. 
Ring X, July 13, 1915. 
1 
19 
61 
24 
0 
II 
8 
Do. 
2 
5 
21 
II 
3 
8 
5 
Rincr 2. Tune 16. iqic. 
I 
20 
14 
38 
Do. 
2 
14. 
12 
2 d 
Do. 
q 
20 
8 
2 d 
Rincr 2. Tulv 13. iqic . 
0 
I 
12 
H 
Tr. 
Do. 
2 
6 
Tr. 
Do . 
*2 
Tr. 
Tr. 
0 
Ring 3, July 13, 1915. 
O 
I 
16 
43 
24 
3 
11 
11 
Do. 
2 
11 
16 
8 
3 
5 
5 
Ring 4, Aug. 16, 1915. 
X 
16 
59 
24 
11 
11 
14 
Ring in oats, July 17, 1915. 
I 
16 
24 
16 
0 
5 
S 
Do.. 
2 
11 
19 
11 
0 
5 
3 
Ring in wheat field, Aug. 12, 1915... 
T 9 
53 
5 
24 
Mean. 
I 
17 
49 
22 
7 
13 
13 
Do. 
2 
9 
19 
10 
5 
6 
9 
Do.. 
q 
10 
4 
12 
O 
