Variations in Moisture Content of a Loess Soil 
455 
Sept. 9,19x8 
insure our finding the extremes occurring during the season. The max- 
imums could be obtained after heavy rains, but in order to maker sure of 
finding the minimums, it was necessary, whenever the soil began to get dry, 
to sample at frequent intervals until the next rain restored a moist con¬ 
dition. It happened that the season of 1912 proved almost as satis¬ 
factory for such a study as any during the 20-year period beginning 
with 1895. 
Table I .—Nitrogen and organic carbon in different inch sections of the surface foot of the 
different fields sampled in 1QI2 
NITROGEN 
Depth. 
Average of 
5 prairie 
fields. 
Grass field. 
Cornfield 
and fallow 
F-C. 
Exposed 
subsoil. 
J. 
M. 
Inches. 
Per cent. 
Per cent. 
Per cent. 
Per cent . 
Per cent. 
0-347 
0 .403 
O.237 
O.237 
0.047 
.279 
.258 
•235 
.218 
.047 
3 . 
-259 
.241 
•235 
.205 
.045 
4 . 
.245 
• 236 
•233 
. 200 
.044 
5 . 
•234 
. 228 
• 253 
. 200 
.044 
6.. 
.223 
. 227 
•251 
-193 
. 04I 
7 . 
. 210 
. 212 
•239 
. 182 
.040 
8...... 
. 201 
. 202 
. 211 
-173 
.038 
9 . 
•193 
.197 
.%88 
. 171 
.038 
.l8l 
. I90 
.171 
. 164 
.038 
*173 
.178 
. 164 
•152 
.038 
• i6 3 
. 170 
.154 
. 142 
.036 
Average: 
i -3 . 
• 29s 
.301 
.236 
. 220 
.046 
4-6 . 
•234 
.230 
. 246 
. 198 
.043 
7-9 .*. 
. 201 
. 204 
•213 
•175 
•039 
10-12. 
. 172 
•179 
. 163 
•*53 
•037 
1-6. 
. 264 
.265 
.241 
. 209 
.044 
7-12. 
. 186 
.191 
.188 
. 164 
.038 
1-12. 
.225 
00 
M 
ei 
.215 
.186 
.041 
3 - 
8 . 
12 
CARBON 
3 - 3 i 
2. 78 
2 .61 
2.18 
2. 39 
2. 27 
2. 27 
1.92 
1.89 
1. 86 
i- 52 
1.42 
CARBON-NITROGEN RATIO 
12.8 
11.6 
11. 2 
10.6 
5-6 
11. 9 
11. 2 
10. 8 
11.1 
4-7 
11. 6 
10.9 
9-7 
10.0 
S-o 
CHARACTER OF SOIL 
The soil of all the fields involved in the study is a silt loam of loessial 
origin, the Marshall silt loam of the Bureau of Soils of the United States 
Department of Agriculture the properties of which we have discussed 1 in 
1 Alway, F. J., McDole, G. R., and Trumbuu, R. S. op. err. 
