380 
Journal of Agricultural Research 
Vol. I, No. s 
growth and blossoming. Moreover, they are apt to be partly hidden, 
owing to their habit of growing close among the stems of the sagebrush. 
After midsummer most of the herbaceous species die, at least to the 
ground, and during the rest of the year typical areas when viewed from 
a little distance appear to contain no species other than Artemisia 
tridentata . 
Physical Conditions Indicated 
The soils occupied by the sagebrush association, which consist largely 
of products of erosion deposited upon the bed of the ancient Take 
Bonneville, are rather coarse in texture and often contain much gravel. 
All available data concerning the moisture conditions and salt content 
of the soil in typical portions of this association as it occurs in Tooele 
Valley are given in Table IV. 
Table IV .—Sagebrush association: Moisture conditions and salt content of the soil in 
typical areas. 1 
Date of collection. 
Item. 
Depth of 
(feet.) 
June. 
August. 
Aver¬ 
age. 
3 
5 
5 
15 
15 
15 
15 
17 
17 
3 
7 
7 
No. of sample... 
15 
25 
27 
36 
37 
38 
39 
40 
4 i 
104 
nr 
US 
f r 
13* 1 
15.9 
16. 7 
12. 6 
15. 7 
18.4 
12.1 
9 3 
0- 0 
14* 3 
Moisture equiv¬ 
J a 
15.6 
17.4 
17. 7 
22.9 
14. 7 
19.1 
8.9 
ic 6 
alent. 
1 3 
23. 8 
13- 3 
22. 2 
24. $ 
15* 2 
7 - 5 
0* 0 
u 
16* c 
U 
19.6 
11.6 
23. 4 
7 * w 
8. 7 
TP. 8 
f I 
7.1 
8.6 
9. I 
6.8 
8. 5 
10.0 
6.6 
Wilting coeffi¬ 
J ^ 
8. 5 
9.4 
9. 6 
12.4 
8.0 
jo. 4 
4.8 
0* v 
A* O 
4 * 4 
& 5 
cient . 
1 3 
12. 9 
7. 2 
12.0 
13.3 
8.2 
4 * 1 
h* y 
Am O 
&9 
1 4 
i c. 6 
6.3 
12. 7 
4 * y 
4*7 
8,6 
Moisture con¬ 
i I 
— , 7 
—i* 4 
—3.0 
—1.2 
— 3 * 7 
” 5 * 0 
-—2. * 
tent above or 
J * 
+3.1 
H- .4 
—1. 5 
-(- . 3 
—2* 5 
— 4 * I 
* j 
— .6 
below the wilt¬ 
1 3 
—4.4 
+ • 7 
— 4 * 4 
+3. 7 
—3. 2 
— I* 3 
ing coefficient. 
( 4 
—1.0 
0 
+ 4 * O 
+x. 0 
( 1 
0.03 
o. 04 
•03 
.04 
•03 
■03 
• 03 
■03 
O.03 
O.03 
•03 
*03 
•03 
*03 
■03 
.04 
. 06 
•03 
.03 
•03 
*03 
•03 
. 02 
•03 
•03 
Salt content. 
< 3 
. 08 
• 03 
. 12 
• °S 
. 02 
. 02 
* 03 
* 05 
1 4 
. 10 
*03 
. 12 
•OS 
• 07 
l s 
*05 
. 10 
*07 
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). —Typical sagebrush land is characterized by a rather 
light texture of the soil, as is indicated by the relatively low moisture 
equivalent. In such soil water penetrates readily to considerable depths, 
and the run-off must be small. Consequently, although the moisture¬ 
holding capacity is low, the total quantity of water available to deep- 
rooted plants is considerable. 
The rapid growth of the sagebrush plants in the early part of the 
summer results in a speedy exhaustion of the moisture available for 
growth, and in most years the water content of the soil to the depth 
reached by the roots is probably reduced by midsummer to below the 
