402 
Journal of Agricultural Research 
Vol. I, No. s 
Table? XII. — Greasewood-shadscale association: Moisture conditions and salt content of 
the soil in typical areas . 1 
Date of collection. 
Depth 
of 
soil 
Item. 
June. 
July. 
(feet). 
Aver- 
4 
7 
27 
3 
3 
6 
29 
age. 
No. of sample. 
19 
35 
63 
66 
69 
75 
98 
f 
22. O 
26. 5 
26. 5 
26. I 
28. 5 
15 -5 
24.1 - 
Moisture equivalent.. 
J 2 
22. 9 
30. 8 
34 - 2 
32. 2 
24. 8 
20. 8 
x 4 . 7 
26.6 
26.1 
1 3 
* 3-3 
35-3 
3 1 * 5 
33-5 
22. 2 
l 4 
27. 0 
30. 2 
31-5 
31-3 
17*5 
24. 2 
26.9 
I 
11. 9 
14.4 
14.4 
14.2 
15 -5 
8.4 
13 - 1 
Wilting coefficient. 
2 
12. 4 
16. 7 
18.6 
17 - S 
18.2 
13 - 5 
8. 0 
14.4 
3 
7.2 
19. 2 
17. 1 
11. 2 
12.1 
14* 2 
4 
14. 7 
16. 4 
17. 1 
17.0 
9-5 
13 -1 
14.6 
f 
— . I 
- • 5 
— 4-4 
— 4.4 
- -3 
- 4-7 
— 2- 47 
Moisture content above or below 
1 2 
+ 4-5 
+ 6.1 
+ 4-1 
+ 3 * 2 
+ 3-1 
+ ■ 4 
+ 3-6 
wilting coefficient. 
1 3 
+ 3-5 
+10. 2 
+ 4-1 
+ 4-3 
+ 8-8 
+ 3*3 
+ 5-7 
| 
l 4 
+ 1.0 
+ 8.4 
+ 3*9 
+ 2.8 
+ 13-1 
+ 2. s 
+ 5 * 3 
f 
.08 
0. 05 
.64 
.27 
■ 54 
. 61 
• 23 
•34 
2 
. 61 
•38 
1. 24 
■ 54 
1. 10 
. 61 
, 60 
. 72 
Salt content. 
. 62 
1. 30 
.82 
1.85 
1.36 
*65 
1. 05 
1. 36 
I. 48 
.68 
• 76 
1*25 
1.03 
i -15 
4 
1. 96 
1. 20 
1. 58 
1 All data in this table are stated in percentages of the dry weight of the soil. The moisture contents 
with a plus sign (+) represent moisture available for growth (above the wilting coefficient), while those 
with a minus sign (—) represent a corresponding deficit of available moisture (below the wilting coefficient). 
Soil, Moisture. —The moisture-holding capacity of the soil, as indi¬ 
cated by the moisture equivalent, is somewhat higher in the first foot, 
but is lower in the second, third, and fourth feet than in the shadscale 
association. It is significant that moisture available for the growth of 
plants was present in considerable quantity during the months of June 
and July in all but the surface foot in the greasewood-shadscale associa¬ 
tion, while in the shadscale association during the same months there 
was a marked deficit of available water to a depth of 4 feet. The rela¬ 
tively high moisture content is correlated with the relatively slight 
elevation above the level of water in the lake and with a consequently 
high ground-water table. 
Salinity. —The average salt content of each of the first 4 feet of the 
soil is much higher than in the shadscale association, the difference being 
especially marked in the second foot, which contains, on the average, as 
much salts as does the third foot in land occupied by pure shadscale. 
Summary of Physical Conditions. —In Tooele Valley the presence 
of typical greasewood-shadscale vegetation indicates soil conditions as 
follows: (1) A fairly high moisture equivalent; (2) the surface foot well 
drained and usually dry during the summer; (3) moisture available for 
the growth of plants present throughout the summer at a comparatively 
slight depth; (4) a high salt content from the second foot downward and 
often in the surface foot as well. / 
