36 
COLORADO EXPERIMENT STATION 
The maximum net g]ain miade by any soil in this series was 606 
p. p. m. of nitric nitrogen by No. 70, the California black adobe; the 
average for all positively reacting samples was 214.76 p. p. m. and the 
minimum 5 p. p. m. by No. 53. 
j Series VII. Dried Blood 
Dried blood was employed as the nitrifiable substance in Series 
VII. Here also we have an increase in the number of soils yielding 
comparatively large gains; it will be remembered that the first series 
gave three such and the next, six, while the present one contains eight. 
Evidently the nitrogen of the dried blood responded more readily to the 
TABLE NO. 7.—Nitrification of Dried Blood by Foreign Soils. Nitrogen in Parts Per Million of 
Air-dried Soil as Nitrites and Nitrates from 100 m.g. Nitrogen as Dried Blood. 
Duration of Experiment: 6 Weeks at 28 Degrees C. 
Nitrogen as nitrites Nitrogen as nitrates Chlorin 
_ , . in parts per million in parts per million in 
Number of Sample and ^^_ a _p_ p. m 
Description 
52 Corn field, clay loam, 
Check 
Check 
Dried blood ' 
Check 
Check 
Dried blood 
Total 
Net 
at 
begin. 
at 
end 
added 
at 
begin. 
at 
end 
added 
gain 
gain 
Ohio . 
53 Pine forest, gravelly 
.002 
.176 
.04 
7.U 
60. 
480. 
473. 
420. 
8. 
loam, Georgia. 
54 Apple orchard, loam, 
Trace 
.220 
.14 
5.0 
Trace 
6. 
L 
6. 
78. 
Washington . 
55 Apple orchard, heavy 
.04 
.340 
.80 
5.0 
90. 
210. 
205. 
120. 
40. 
clay, Virginia. 
56 Cotton field, siandy 
Trace 
.160 
.056 
9.0 
70. 
720. 
711. 
650. 
74. 
loam, Oklahoma . . 
57 Water melons, sandy 
.18 
.168 
.12 
11.0 
50. 
80. 
69. 
30. 
8. 
loam, North Carolina 
58 Cotton field, sandy 
T race 
.168 
.12 
7.0 
46. 
Trace 
—7. 
—46. 
10 . 
loam, Texas . 
59 Cotton field, clay 
.12 
.160 
.06 
7.0 
50. 
200. 
193. 
150. 
98. 
loam, Georgia .... 
60 Corn field, clay, 
Trace 
.152 
.12 
14.0 
60. 
240. 
226. 
180. 
106. 
North Carolina .... 
61 Tobacco field, sandy 
.16 
.112 
.072 
6.0 
70. 
560. 
554. 
490. 
8. 
loam, N. Carolina. . . 
62 Vineyard, clay loam, 
T race 
.100 
.18 
3.0 
20. 
0 . 
—3. 
—20. 
6. 
California . 
63 Alfalfa field, sandy 
Trace 
Trace Trace 
4.0 
24. 
180. 
176. 
156. 
26. 
loam, California 
64 Small grain, sandy 
.04 
.100 
5.00 
4.0 
46. 
20. 
16. 
—26. 
8. 
loam, California 
65 Cotton field, sandy 
.88 
.320 
.32 
6.0 
70. 
640. 
534. 
570. 
8. 
loam, Arkansas .... 
66 Cane field, clay loam, 
.60 
.132 
30.00 
4.0 
24. 
110. 
106. 
86. 
62. 
Oklahoma . 
67 Mixed orchard, silt 
.18 
.136 
.40 
40.0 
126. 
180. 
140. 
54. 
6 . 
loam, California . . . 
68 Plum orchard, sandy 
1.80 
1.800 
44.00 
120.0 
140. 
220. 
100. 
80. 
700. 
loam, California.... 
69 Virgin soil, clay, Cali- 
.26 
.140 
70.00 
7.4 
40. 
80. 
72.6 
40. 
8. 
fornia . 
70 Small ~’-ain, black 
T race 
.100 
.60 
2.0 
30. 
280. 
278. 
250. 
8. 
adobe, California .... 
71 Raw cactus land, sand 
1.40 
.160 
.20 
5.0 
34. 
640. 
635. 
606. 
10 . 
and gravel. Calif. 
73 Vineyard, sandy loam, 
T ra ce 
.120 
.32 
0.0 
12. 
10. 
10 . 
—2. 
6. 
California . 
74 Sugar beets, sandv 
0.00 
.120 
.52 
7.4 
70. 
400. 
392.6 
330. 
8. 
loam, Kansas . 
1.20 
.260 
.96 
26.0 
160. 
760. 
734. 
600. 
2,000. 
nitrifying agents than did the nitrogen of the ammonia salts; whether 
this was due to its being present in a more available form or whether 
the additional food material in the blood stimulated microbic activity 
can only be conjectured. 
