24 
COLORADO EXPERIMENT STATION 
Considering only those soils which gave positive results, there 
seems to be practically no difference in the activity of our normal and 
incipient niter soils as measured by their ability to nitrify ammonium 
sulphate 
Looking next to the samples that show either no gain or a loss of 
nitric nitrogen, we find that with the exception of No. 78, the raw 
TABLE NO. 1.—Nitrification of Ammonium Sulphate by Colorado Soils. Nitrogen in Parts Per Million of 
Air-dried Soil as Nitrites and Nitrates from 100 m.g. Nitrogen as (NH < ) o S0 4 
Duration of Experiment: 6 Weeks at 28 Degrees C. 
Nitrogen as nitrites 
tvt , c c i j in parts per million 
Number of Sample and ____^_ 
Description. 
Check 
Check 
(NH 4 ) 2 ‘ 
75 Wheat field, clay, nor- 
at 
begin. 
at 
end 
added 
inal . 
76 Truck garden, river 
.88 
.36 
1.60 
bottom, loam, normal 
77 Oat field, clay loam, 
1.20 
.002 
.92 
niter . 
78 Raw land, adobe 
.32 
.26 
2.00 
hill . 
79 Apple orchard, red 
.36 
.60 
25.00 
clay loam, niter.... 
80 Apple orchard, clay 
.26 
.60 
9.60 
loam, niter . 
81 Barren field, brown 
.28 
.90 
68.00 
crust, niter . 
82 Barren field, clay, 
.32 
.22 
1.60 
niter . 
83 Apple orchard, heavy 
1.60 
.80 
1.60 
clay, niter . 
84 Apple orchard, heavy 
.02 
.36 
2.40 
clay, niter . 
85 Apple orchard, clay 
.14 
.52 
1.00 
loam, niter . 
86 Oat field, sandy loam 
.012 
.10 
2.00 
niter . 
87 Apple orchard, clay 
.0 
.14 
.10 
loam, niter . 
88 ripple orchard, clay 
.10 
.12 
.60 
loam, niter . 
89 Apple orchard, clay 
.40 
.14 
.80 
loam, niter . 
90 Apple orchard, sandy 
.40 
.60 
.14 
loam, niter . 
91 Apple orchard, heavy 
.32 
.40 
.36 
clay, normal . 
92 Oat field, sandy loam, 
.32 
.14 
.10 
niter . 
93 Peach orchard, heavy 
1.40 
.20 
.36 
clay, normal . 
94 Apple orchard, clay 
.60 
.60 
2.40 
niter . .. 
95 Apple orchard, brown 
.14 
1.20 
.10 
surface . 
96 Peach orchard, sandy 
.26 
.14 
.60 
loam, normal . 
97 Apple orchard, clay 
.24 
1.00 
2.40 
niter . 
.36 
1.40 
.24 
Nitrogen as nitrates Chlorin 
in parts per million in 
Check 
at 
begin. 
Check 
at 
. end 
(NH 4 ) 2 S0 4 
added 
Total 
gain 
Net 
gain 
p. p. m. 
7. 
64. 
800. 
793. 
736. 
500. 
54. 
110. 
660. 
606. 
550. 
400. 
26. 
76. 
800. 
774. 
724. 
4,500. 
140. 
140. 
108. 
—32. 
—32. 
7o0. 
5. 
66. 
600. 
595. 
534. 
1,000. 
13. 
50. 
36. 
23. 
—14. 
10,000. 
1360. 
1360. 
1240. 
—120. 
—120. 
32,400. 
46. 
120. 
660. 
614. 
540. 
9,800. 
6. 
100. 
1040. 
1034. 
940. 
58. 
Trace 
68. 
1040. 
1040. 
972. 
138. 
6. 
60. 
600. 
594. 
540. 
1,000. 
130. 
240. 
200. 
70. 
—40. 
6,400. 
6. 
40. 
840. 
834. 
800. 
202. 
70. 
100. 
100. 
30. 
0 . 
8,300. 
180. 
260. 
800. 
620. 
540. 
1,600. 
13. 
60. 
800. 
867. 
820. 
140. 
Trace 
40. 
720. 
720. 
680. 
80. 
, 320. 
320. 
240. 
—80. 
—80. 
7,800. 
4. 
48. 
880. 
876. 
832. 
120. 
34. 
92. 
500. 
466. 
408. 
420. 
600. 
640. 
960- 
360. 
320. 
150. 
20. 
60. 
720. 
700. 
660. 
170. 
20. 
132. 
960. 
940. 
828. 
65. 
adobe hill, all contain very high chlorin; in fact with the exception of 
No. 82, which gave positive results, the five soils with the highest 
chlorin are the negative soils. Lipman (i) has shown experimentally 
that when sodium chlorid is present in soil in amounts equivalent 
(1) Lipman, Chas. B., Toxic Effects of “Alkali Salts” in Sods on Soil Bacteria. 
II Nitrification. Cent. f. Bakt., II. Abt., Bd. 33, p. 305, 1912. 
