The Fixation of Nitrogen in Colorado Soils 
Samples taken 
1. 1 to 3 inches . 
4 to 7 inches . 
2. 1 to 3 inches . 
4 to 7 inches . 
3. 1 to 3 inches . 
4 to 7 inches . 
4. 1 to 3 inches . 
4 to 7 inches . 
5. 1 to 3 inches . 
4 to 7 inches . 
6. 1 to 3 inches . 
4 to 7 inches . 
Alfalfa field . 
Brown surface soil . 
12 feet from edge of “brown spot’’. 
“Brown spot” . 
“Brown spot” . 
Samples taken 
1. 
1 
to 
3 
inches 
4 
to 
7 
inches 
2. 
1 
to 
3 
inches 
4 
to 
7 
inches 
3. 
1 
to 
3 
inches 
4 
to 
7 
inches 
4. 
1 
to 
3 
inches 
4 
to 
7 
inches 
5. 
1 
to 
3 
inches 
4 
to 
7 
inches 
*6. 
1 
to 
3 
inches 
4 
to 
7 
inches 
Alfalfa field . 
Brown surface soil . 
Brown soil tree holes . 
“Brown spot” . 
“Brown spot” ... 
“Brown spot” . 
Surface-soil 16 feet from edge of last sample 
Samples taken 
1. 
1 
to 
3 
inches 
4 
to 
7 
inches 
2. 
1 
to 
3 
inches 
4 
to 
7 
inches 
3. 
1 
to 
3 
inches 
4 
to 
7 
inches 
4. 
1 
to 
3 
inches 
4 
to 
7 
inches 
5. 
1 
to 
3 
inches 
4 
to 
7 
inches 
6. 
1 
to 
3 
inches 
4 
to 
7 
inches 
Alfalfa 
field . .. 
“Brown spot” 
“Brown spot” 
May 15, 1912. 
Nitric Nitrogen 
Total Nitrogen 
Chlorin 
190.0 
992.8 
1,797.7 
20.0 
693.6 
634.9 
274.9 
992.8 
948.3 
74.8 
666.4 
659.7 
253.1 
965.6 
329.8 
20.0 
625.6 
602.0 
30.0 
741.2 
602.0 
15.0 
625.6 
371.1 
5.0 
639.2 
140.2 
5.0 
544.0 
329.8 
3.0 
680.0 
338.1 
1.5 
557.6 
359.8 
80.0 
1,761.2 
18,554.0 
3,814.0 
5,412.8 
12,493.0 
7.0 
557.6 
247.4 
8,702.0 
9,329.6 
14,060.8 
5,312.5 
6,120.0 
21,935.0 
June 12, 1912. 
Nitric Nitrogen 
Total Nitrogen 
Chlorin 
253.6 
938.4 
2,597.5 
16.0 
673.2 
676.1 
289.3 
1,156.0 
8,106.0 
194.5 
843.2 
890.6 
324.2 
1,081.2 
2,185.3 
16.0 
683.4 
593.7 
117.1 
'< ul.6 
808.1 
12.0 
5,511.6 
222.7 
24.0 
632.4 
453.5 
4.0 
516.8 
. 329.8 
6.0 
686.8 
313.3 
8.0 
584.8 
907.1 
Nitric Nitrogen 
Total Nitrogen 
Chlorin 
20.0 
1,999.2 
19,024.0 
6,970.9 
7,684.2 
23,304.0 
1,228.7 
1,873.2 
4,813.0 
15,275.0 
17,272.0 
18,908.0 
5,231.5 
6,079.2 
19,131.0 
7,077.0 
8,500.0 
13,812.0 
16.0 
591.6 
273.9 
13 July, 1912. 
Nitric Nitrogen 
Total Nitrogen 
Chlorin 
261.4 
952.0 
2,482.0 
12.0 
754.8 
667.9 
351.9 
1,081.2 
1,896.5 
57.2 
686.8 
658.2 
266.0 
897.7 
1,467.8 
35.0 
625.6 
247.4 
107.8 
870.4 
676.2 
42.2 
646.0 
272.1 
12.0 
652.8 
247.4 
6.0 
646.0 
164.9 
10.0 
693.6 
123.7 
0.5 
476.0 
206.2 
25.0 
1,788.4 
18,743.0 
11,287.5 
13,804.0 
15,733.0 
4,356.5 
5,562.4 
17,993.0 
♦This section No. 6 had been irrigated quite recently. 
