228 
Journal of Agricultural Research 
Vol. IX, No. 7 
Table XXI .—Distribution of nitrates at right angles to furrows, Citrus Experiment 
Station grove, Riverside, CaL August J, igi6 
[Results expressed as milligrams of nitrogen per ioo gm. of soil) 
Plot No. 
Depth. 
Boring No. 
Aver¬ 
age. 
1 
2 
3 
4 
5 
6 
7 
■8 
9 
Inches. 
0- 3 
2.60 
3 * 58 
12.08 
13*41 
29.30 
21.00 
20.41 
7.40 
7-33 : 
13*01 
3 “ 6 
.61 
.89 
1.23 
x. x6 
3*89 
2.00 
1*34 
.64 
.19 
i *33 
6 r- 9 
•57 
•57 
•32 
*95 
2.00 
1.30 
1.38 
•43 
.68 
.91 
9-12 
.29 
•50 
.88 
1.79 
i* 5 i 
1.02 
x.48 
.64 
.61 
•97 
0- 3 
.28 
. 42 
x.06 
1.58 
x.06 
• 67 
• 32 
. 78 
3- 6 
. 18 
• 15 
.08 
. 64 
.18 
. 11 
• 15 
♦ 21 
6— 9 
• J 5 
.18 
.08 
• *5 
. 11 
. 11 
.18 
• IA 
B. 
O—T 2 
« .08 
.18 
.08 
. 11 
.08 
.08 
.08 
V 
12—24 
.08 
24—36 
36-48 
* * J 
, Xj 
0- 3 
•43 
3-58 
6.66 
4*35 
35-01 
19.61 
5-47 
1. 41 
.89 
8» 60 
fl. 
3 - 6 
.40 
3.96 
•99 
2* 39 
10. 23 
1.87 
•36 
.29 
•15 
2. 29 
6- 9 
•33 
• 36 
.26 
•92 
3-74 
2.27 
•50 
• 19 
.19 
•97 
9-12 
•43 
•36 
•36 
x. 27 
2.04 
•99 
.40 
•29 
.29 
. 72 
0- 3 
2 . IO 
11.80 
23.10 
67.90 
21.49 
4 * 50 
2.50 
1*50 
.90 
15.09 
3 - 6 
.27 
X. xo 
X.96 
3 * 7 S 
6.08 
5-46 
•56 
.28 
. 26 
2.19 
I*. 
6- 9 
.24 
2.00 
2 . XO 
•95 
2.80 
5* 20 
•79 
.28 
.24 
1.62 
9-12 
•25 
.20 
1.85 
I. 20 
2. 20 
1.49 
x. 20 
.40 
.18 
1.00 
. 12-15 
.21 
. 2 X 
•44 
I. 00 
.98 
.78 
.60 
•36 
. 21 
•53 
0- 3 
.28 
.30 
4.10 
4.40 
X. xo 
.76 
•49 
.28 
1.46 
3 - 6 
• 20 
.28 
*56 
• 65 
•42 
.40 
.28 
.28 
•38 
M. 
6- 9 
• 20 
• 56 
. 84 
• 56 
• 30 
.48 
* 20 
.18 
. 9-12 
.18 
.18 
. 2 X 
,28 
• 41 
•35 
* 26 
•24 
* 
* 26 
as fromfmroiy 
/smwfvmow 
O z 6 
In plot A it is ob¬ 
served that the highest 
amount of nitric nitro¬ 
gen found in the upper 
3 inches of soil was 
in boring 5—29.30 
mgm.—while the 
amount found in the 
surface 3 inches in bor¬ 
ing 1 amounted to only 
2.60 mgm. The high¬ 
est amounts found in 
the second and third 
sections were also for 
boring 5, which was 
about midway between 
the furrows. It is 
therefore apparent that the distribution of nitrates in this soil was 
influenced to a considerable extent by the irrigation. The column of 
averages for plot A shows that 80 per cent of the nitrates in the upper 
foot was found in the surface 3 inches, and the next highest amount 
was at a depth of 3 to 6 inches. 
The samples from plot B were taken between furrows run at a distance 
of 28 inches. Only seven borings were therefore necessary to remove the 
6-/6 
/6-SO’\ 
3cr-4e 
/sr 3*0. 4t?77/. /sr. 3 / 90 . 4t?Trt /sr 3*0- 47*. 
/VO. OF //?/?/<?* T/O/V 
Fig, i 5.—Diagram showing the distribution of nitrates in plot TJ before 
and after irrigations. Season of 1916. 
