778 
Journal of Agricultural Research v 0 i. xxviii, no. 8 
Seepweed with Other Plants 
Seepweed mixes with many other plants but these mixtures are of minor im¬ 
portance, covering only small areas. Table XXIX shows the salt content of the 
soil on which several of these mixtures occurred. The salt content is high 
wherever seepweed is found, with the exception of land formerly cultivated. 
ATRIPLEX FASCICULATA 
The land covered by Atriplex fasciculata S. Wats, is similar in appearance and 
texture of soil to the “bare flats” or “slick land” discussed under the next 
heading. In fact, it is merely that part of the bare flats, usually only the outer 
edges in the larger bare flats, where the soil conditions have been made more 
favorable by the rains, that this Atriplex springs up. The communities formed by 
Atriplex fasciculata, although small, are pure. Only at the outer borders do they 
mix with Atriplex linearis S. Wats, and scattered Lycium parvifiorum A. Gray. 
Atriplex fasciculata S. Wats, appears as a small annual from 6 to 10 inches high. 
It is often dense enough to cover the ground completely. This plant springs up 
after the rains when there is water in the surface foot on the flats, grows rapidly 
and as the water is exhausted the plants mature. Where sample No. 5, Table 
XXX, was collected, there is a heavy layer of silt on the surface that hinders 
penetration. There was no available water here in the fall. Sample No. 11, 
Table XXX, shows a lighter soil, better penetration, and some available water in 
the fall in all the feet except the first. 
The salt content is high (Table XXX) with an appreciable quantity even in 
the first foot. 
Table XXX.— A comparison of spring and fall soil conditions at the same station 
in a hare flat ° 
Item 
Depth 
Chandler, Ariz., 
1915, date of 
collection 
Casa Grande, Ariz., 
1915, date of 
collection 
of soil 
Mar. 25, 
sample 
No. 15 
Oct. 7, 
sample 
No. 15 
Oct. 11, 
sample 
No. 5 
Oct. 11, 
sample 
No. 11 
Moisture equivalent..... 
Feet 
1 
20.1 
19.7 
22.9 
17.7 
2 
18.9 
18.6 
19.2 
17.5 
3 
16.0 
18.2 
12.3 
17.1 
4 
15.9 
19.2 
12.0 
17.9 
W ilting coefficient.... 
1 
10.9 
10.7 
12.4 
9.6 
2 
10.3 
10.1 
10.4 
9.5 
3 
8.4 
9.9 
6.7 
9.3 
4 
9.0 
10.4 
6.5 
9.7 
Moisture content above or below wilting coefficient.. 
1 
-1.3 
-4.4 
cd 
cd 
2 
-0.5 
0.0 
d 
sm 
3 
+0.4 
+ 1.2 
d 
sm 
4 
+0.9 
+2.9 
d 
sm 
Salt content.. 
1 
2.12 
2.68 
.28 
.34 
2 
2 . 82 
2.68 
.48 
1.00 
3 
1.46 
1.96 
.32 
.81 
4 
1.00 
1. 58 
.34 
.81 
a All data in percentages of the dry weight of the soil. 
6 Partly covered with an annual, Atriplex fasciculata S. Wats. No samples were taken here in spring, 
c d=dry soil; sm=slightly moist soil. 
