20 
Colorado Experiment Station 
The amount of nitric nitrogen found in soil, cultivated fallow, 
compared with the foregoing results on the one hand, and with the 
nitric nitrogen found in cropped soil on the other hand, is of interest 
in this connection. 
The cropped land referred to in the following tables is the same 
land for which the nitric nitrogen is subsequently given as sampled 
i August, 1913, Defiance, Check, Section 1700. The wheat was 
harvested off of the land 6 August. The land was irrigated 28 Au¬ 
gust and disked a few days later. The land was plowed about 20 
October, and the samples were taken 4 December, 1914. These 
facts are stated in order that the part played by the cultural condi¬ 
tions may be taken into proper consideration. 
Six series of samples were taken from the adjoining section 
of land, three on 14 November and three on 4 December, 1914. This 
section had been cultivated fallow during the season preparatory for 
use in wheat breeding experiments. The area of these sections is 
two acres each. 
NITRIC NITROGEN IN FALLOWED LAND. 
SAMPLES TAKEN 14 NOVEMBER, 1914. 
Nitric Nitrogen Parts per Million 
Depth. N Sample I. Sample II. Sample III. 
0 to 3 inches. 6.36 8.52 7.37 
4 to 7 inches. 20.71 28.63 22.03 
8 to 13 inches. 9.24 18.73 14.74 
14 to 19 inches. 5.63 3.89 3.88 
SAMPLES TAKEN 4 DECEMBER, 1914. 
0 to 3 inches. 11.12 7.44 14.32 
4 to 7 inches. 31.13 18.42 25.71 
8 to 13 inches.'.. 17.11 15.67 18.73 
14 to 19 inches. 6.57 4.79 6.43 
TOTAL NITROGEN IN FALLOWED LAND. 
SAMPLES TAKEN 4 DECEMBER, 1914. 
Depth. Percent Percent Percent 
0 to 3 inches. 0.1293 0.1244 0.1230 
4 to 7 inches. 0.1319 0.1265 0.1225 
8 to 13 inches. 0.0974 0.1091 0.0987 
14 to 19 inches. 0.U709 0.0705 0.0677 
NITRIC NITROGEN IN LAND CROPPED TO WHEAT. 
SAMPLES TAKEN 4 DECEMBER, 1914. 
Depth. 
0 to 3 inches 
4 to 7 inches 
8 to 13 inches 
14 to 19 inches 
Nitric Nitrogen Parts per Million. 
Sample I Sample II 
. 6.39 5.42 
. 11.74 7.92 
. 11.82 8.93 
. 6.69 3.44 
TOTAL NITROGEN IN LAND CROPPED TO WHEAT. 
SAMPLES TAKEN 4 DECEMBER, 1914. 
Depth. " Percent 
0 to 3 inches. 0.1258 
4 to 7 inches. 0.1223 
8 to 13 inches. 0.1203 
14 to 19 inches. 0.0820 
Percent 
0.1150 
0.1205 
0.1101 
0.0764 
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