768 
Journal of Agricultural Research 
Vol. XXVIII, No. 8 
Table XXI.— Comparison of spring and fall soil conditions at the same stations 
in typical areas of mesquite and chamiso, Indio, Calif., 1915 a 
Date of collection 
Date of collection 
Item 
Depth 
of 
soil 
Mar. 
3, 
sam¬ 
ple 
No. 
16 
Mar. 
2, 
sam¬ 
ple 
No. 
17 
Mar 
2, 
sam¬ 
ple 
No. 
18 
Mar. 
2, 
sam¬ 
ple 
No. 
19 
Mar. 
2, 
sam¬ 
ple 
No. 
20 
Aver¬ 
age 
Sept. 
20, 
sam¬ 
ple 
No. 
16 
Sept. 
21, 
sam¬ 
ple 
No. 
17 
Sept. 
21, 
sam¬ 
ple 
No. 
18 
Sept. 
23, 
sam¬ 
ple 
No. 
19 
Sept. 
23, 
sam¬ 
ple 
No. 
20 
Aver¬ 
age 
Moisture equivalent 
Feet 
1 
2.3 
2.0 
2.6 
2.1 
2.7 
2.3 
2.4 
3.1 
3.3 
2.2 
2.2 
2.6 
2 
2.9 
3.0 
2.9 
2.5 
2.3 
2.7 
2.9 
3.3 
2.7 
2.6 
2.7 
2.8 
3 
2.8 
3.4 
2.5 
2.2 
1.9 
2.6 
3.3 
3.9 
1.9 
2.7 
2.4 
2.8 
4 
2.6 
3.1 
3.0 
2.6 
2.6 
2.8 
3.8 
4.5 
2.2 
2.6 
2.3 
3.1 
Wilting coefficient.. 
1 
1.3 
1.1 
1.4 
1.1 
1.5 
1.3 
1.3 
1.7 
1.8 
1.2 
1.2 
1.4 
2 
1.6 
1.6 
1.6 
1.3 
1.3 
1.5 
1.6 
1.8 
1.5 
1.4 
1.5 
1.6 
3 
1.5 
1.9 
1.4 
1.2 
1.0 
1.4 
1.8 
2.1 
1.0 
1.5 
1.3 
1.5 
4 
1.4 
1.7 
1.6 
1.4 
1.4 
1.5 
2.1 
2.4 
1.2 
1.4 
1.3 
1.7 
Moisture content 
1 
+2.5 
+2.2 
+3.1 
+2.1 
+2.1 
+2.4 
-1.2 
-1.5 
-1.7 
-1.0 
-1.1 
-1.3 
above or below 
2 
+3.8 
+3.8 
+3.5 
+3.9 
+3.9 
+3.8 
0.0 
-1.6 
-1.0 
-1.2 
-1.1 
-1.0 
wilting coefficient- 
3 
+4.1 
+5.9 
+2.4 
+3.0 
+4.8 
+4.1 
+0.9 
-1.7 
+0.5 
-1.2 
0.0 
-0.3 
4 
+0.8 
+1.0 
+0.1 
-0.2 
+0.5 
+0.4 
+0.8 
-1.6 
+1.1 
-0.9 
-0.1 
-0.1 
Salt content. 
1 
<.01 
<. 01 
<.01 
<.01 
<. 01 
<.01 
<.01 
<.01 
.02 
<. 01 
<.01 
.01 
2 
<.01 
<.01 
<. 01 
<.01 
.01 
<. 01 
.01 
<.01 
<.01 
<. 01 
.02 
.01 
3 
.02 
<. 01 
<.01 
<.01 
.06 
.02 
<.01 
.01 
<.01 
<.01 
.02 
.01 
4 
.02 
.03 
.02 
.02 
.02 
.02 
.02 
.02 
.12 
<.01 
.01 
.04 
a All data in this table are stated in percentages of the dry weight of the soil. 
Salinity 
The salt content of the soils of this area is very low (Table XXI), which is 
expected in soil that is practically pure sand. 
Summary of Physical Conditions 
The lands covered by mesquite and chamiso show: (1) Practically a pure sand 
with very good penetration and low run-off, but low moisture-holding capacity; 
(2) a good supply of moisture after the winter rains to a depth of 4 feet; (3) a 
very low salt content. 
ADAPTATIONS TO PHYSICAL CONDITIONS 
The chamiso begins growth much earlier than the mesquite and because of its 
shallower root system (PI. 11, B) makes use of the moisture collected in the upper 
4 feet of soil during the rainy season. As soon as the weather becomes hot some 
of the lower leaves fall off so that by late summer the plants are almost leafless 
but bear large quantities of fruit. 
Since the moisture supply of the mesquite is not so limited, and since it 
sends its roots to a greater depth, it is therefore much less conservative than 
the chamiso in regard to water loss in the hot months of the year. 
The mesquite and chamiso land in the Coachella Valley is capable of crop pro¬ 
duction where the sand hills are not too high. Some of the lower and older dunes 
where water from artesian wells was available have already been leveled and 
planted to dates, and it is apparent that a large part of this area can be so 
utilized. 
