9i4 
Journal of Agricultural Research 
Vol. V, No. 20 
Table II. —Relation of nitrogen to humus in arid soils from California 
Sample No. 
Depth. 
Location and description 
of soil. 
Humus. 
Humus 
ash. 
Total 
nitro¬ 
gen. 
Nitrogen in 
humus. 
Humus 
nitro¬ 
gen. 
Found. 
Maxi¬ 
mum 
possi¬ 
ble. 
Inches. 
P. ct. 
P. ct. 
P. ct. 
P, ct. 
P.ct. 
P. ct. 
A. 
0-3 
Berkeley. Adobe, 
I. 71 
O. 46 
0. 260 
O. 160 
9-3 
15*2 
B. 
O—"2 
virgin. 
I. 10 
. 2 $ 
. 233 
. I IQ 
10. 0 
19 6 
C. 
0-6 
Waterford. Alluvi- 
, 62 
•39 
.054 
•035 
5-6 
8.7 
um, cultivated. 
D .. 
0-6 
Ceres. Loam, cul- 
•31 
• 25 
.031 
. 021 
6.7 
10. 0 
vated. 
E .. 
0-3 
Fresno. Red hog- 
•47 
• 52 
. 026 
. OI9 
4.1 
5-5 
wallow land, vir- 
F. 
0-6 
gtn. 
Clovis. Red land, 
.29 
.18 
.032 
.025 
8.3 
11.0 
cultivated. 
G . 
0-6 
Fresno. Black 
i- 39 
.92 
• 144 
. 087 
6-3 
10.4 
adobe, cultivated. 
H. 
°”5 
Fresno. Dry bog, 
•75 
•45 
00 
t-. 
0 
.030 
4. 0 
10. 4 
I . 
o -5 
Fresno. Dry bog, 
.84 
.29 
. 104 
. o6l 
7.2 
12.4 
cultivated. 
J . 
0-5 
Clovis. Red land, 
• 38 
. 16 
. 060 
.032 
8.8 
15.6 
cultivated. 
K. 
0—c 
.do. 
, 36 
• 17 
. 052 
• °37 
10. 4 
14. 4 
L . 
0-6 
Delano. Alluvium, 
.40 
• 14 
. 070 
.047 
11. 8 
i 7-5 
cultivated. 
M . 
0-6 
Delano. Red land, 
• 5 ° 
• 3 2 
. 061 
.036 
7-5 
12. 2 
cultivated. 
N . 
0—6 
.do . 
. 38 
. 17 
. 061 
• °34 
0. 0 
15.1 
0 . 
0-2 
Delano. Red land, 
1. 00 
•34 
• J 59 
• Ir 5 
ii -5 
i 5-9 
virgin. 
P . 
0-2 
Delano. Alluvium, 
1. 17 
. 20 
.187 
. 140 
12.0 
16. 0 
virgin. 
Average. 
• 73 
. 101 
. 062 
8.3 
13 - 1 
All the samples, except the two from Berkeley, Cal., were secured in 
the San Joaquin Valley in the vicinity of Modesto, Fresno, and Delano, 
where the normal annual precipitation amounts to 10.9, 9.0, and 6.1 
inches, respectively. Samples A and B were both taken from the high 
hill just east of the buildings on the grounds of the University of Cali¬ 
fornia. Sample A is a composite of 20 samples from near the summit, 
and B of the same number from the lighter colored soil to the west, below 
the summit. Sample C was from a cultivated field east of Modesto 
and 4 miles west of Waterford. Sample D was from a fallowed field 
3 miles south of Hickman and 12 miles east of Ceres, E from the virgin 
red hog-wallow land 7 miles north of Fresno, and F from the red lands 
10 miles east of Clovis. The last-named had been under cultivation 
from 15 to 20 years. Sample G is a black adobe from the same farm 
as sample F, and the field had been under crop for about 7 years. Sam¬ 
ples H and I are “dry-bog soils” from a hilltop near the farm from 
