456 
Journal of Agricultural Research 
Vol. XIV, No. II 
detail in other articles (1,4). In Table I there is reported the nitrogen 
content of the different inch sections of the fields sampled in 1912, and, 
for the purposes of comparison, also that of the virgin prairies in the 
vicinity. The samples used for analysis were composites of equal weights 
from all the samples on which moisture determinations h^d been made 
throughout the season; and thus, for example, from 14 borings in the 
case of the grass field J and from 36 in the fallow. The data on the 
prairies represent composites from 250 borings, 50 from each of 5 fields 
(7, p . 206). As the ratio of organic carbon to nitrogen does not change 
greatly in passing from the first to the twelfth inch in prairies (j, p . 231), 
or even in the ordinary cultivated fields, as may be seen from Table I, 
the variations in nitrogen may safely be assumed to be accompanied by 
corresponding variations in the content of organic matter. The low 
nitrogen content and low carbon nitrogen ratio characteristic of the sub¬ 
soils is shown in the samples from all levels of the exposed subsoil. 
TabIvK II .—Hygroscopic coefficients of the inch sections from the different fields 
Depth. 
Grass field J. 
Grass field M. 
Com and fallow field. 
Exposed subsoil. 
Set I. 
Set 
II. 
Aver¬ 
age. 
Set I. 
Set 
II. 
Aver¬ 
age. 
Set I. 
Set 
II. 
Set 
III. 
Set 
IV. 
Aver¬ 
age. 
Set I. 
Set 
II. 
Aver¬ 
age. 
- 
Inches. 
P. ct. 
P. ct. 
P.ct. 
P.ct. 
P. ct. 
P.ct. 
P.ct. 
P. ct. 
P.ct. 
P. ct. 
P. ct. 
P.ct. 
P.ct. 
P.ct. 
1. 
10.1 
9 * 5 
■ 9*8 
8.4 
7*4 
7*9 
8.7 
8.5 
8.8 
7*9 
8*5 
13 . 7 
12. 5 
12.6 
2 .,. 
9. O 
8- 9 
9.0 
8.0 
8.0 
8.5 
8*2 
8.7 
8.6 
8. s 
12. 7 
12.6 
12.6 
3. 
9.0 
8.6 
8.8 
8.1 
8.1 
8-5 
8.9 
9.3 
9.0 
8.9 
12.8 
13.0 
12.9 
4.. 
8. s 
8. 5 
8. 5 
7.8 
7.9 
7 * 9 
8.2 
8*5 
9. 2 
9.0 
8.7 
13. 2 
13* 2 
13. 2 
5. 
8.8 
8.4 
8.6 
8.0 
8*5 
8.3 
8*5 
8-7 
8-7 
9.2 
8.8 
13*2 
12.6 
12.9 
6. 
9.0 
8.8 
8.9 
8.1 
8-6 
8.4 
8.7 
8-7 
9.2 
9*5 
8.8 
13 * 2 
12. 5 
12.9 
7. 
8.8 
9.6 
9. 2 
8.9 
9.0 
9.0 
8.8 
9.4 
9.3 
8.0 
8.9 
12.8 
12.6 
12- 7 
8. 
8.9 
9.5 
9. 2 
9.0 
9.6 
9 * 3 
8. 7 
9. 9 
10. 5 
8- 4 
9.4 
12.7 
12.6 
12. 7 
9 . 
8-5 
9.4 
9.0 
9.1 
9 - 7 
9*4 
9*3 
9*6 
10. 5 
9.2 
9*7 
12.7 
12.7 
12.7 
10. 
8-7 
10.0 
9.4 
9 - 7 
10.3 
10.0 
10.3 
10.0 
11. 2 
9*3 
10. 2 
12.3 
12.4 
12.4 
11. 
9.2 
10. 7 
10.0 
10.1 
11.1 
10.6 
11.1 
ro. $ 
11.6 
9.8 
10. 8 
12.4 
12. 7 
12.6 
13 , ... 
9.1 
10. 7 
9.9 
10. 0 
12 - 5 
ii*3 
11. 2 
ii*3 
12.6 
10. s 
11.4 
12. 2 
12.9 
12.6 
Average: 
1 to 6.... 
9.1 
8.8 
9.0 
8.1 
8.1 
8-5 
8.6 
9.0 
8.7 
8.7 
130 
12. 7 
12.9 
7 to 13 . .. 
8.9 
10.0 
9.4 
9*5 
10.3 
9.9 
9.9 
10.1 
11.0 
9.2 
10.1 
12*5 
12. 6 
12.6 
1 to 13 ... 
9.0 . 
9.4 
9.2 
8.8 
9.0 
9.2 
9.4 
10.0 
9.0 
9.4 
12. 7 
12. 7 
13.7 
No analyses were made of the samples taken in 1910, but these were 
from fields very similar to the grass field and fallow mentioned in Table I. 
In the case of 1910 samples the hygroscopic coefficient was determined 
for each sample in which the moisture content was obtained, but in 1912 
we confined this determination to four sets from one field and two from 
each of the others, each sample being a composite of two borings (Table 
II). While in the case of the portion of the foot section below the reach 
of the plow it would have been far better to have had a determination of 
the hygroscopic coefficient of each sample, the amount of labor involved 
made this prohibitive. The results from the duplicate or quadruplicate 
sets are sufficiently concordant to make it appear probable that in using 
the averages of these we introduce no serious errors. In the case of 
fields M and F-C, in which the surface soil through cultivation had been 
