824 
Journal of Agricultural Research 
Vol. XXX, No. 9 
Table III.— Soil-moisture content in acre-inches hy foot sections to a depth of 4 feet 
in mulched and unmulched soils, at the beginning and at the end of the first absorp¬ 
tion period of the fallow, together with gains in moisture during the absorption 
period , Adams Branch Station, Lind, Wash., 1920 to 1923, inclusive 
Soil section 
1920-1921 
1921 
-1922 
Mulched, fall 
plowed 
Unmulched, 
stubble 
Mulched, fall 
disked 
Unmulched, 
stubble 
Aug. 
16, 
1920 
Apr. 
14, 
1921 
Gain 
Aug. 
16, 
1920 
Apr. 
14, 
1921 
Gain 
Aug. 
10 , 
1921 
Apr. 
7, 
19^2 
Gain 
Aug. 
10 , 
1921 
Apr. 
7, 
1922 
Gain 
First foot... 
0.24 
1. 52 
1 . 28 
0.24 
1 . 76 
1.52 
0.28 
1.70 
1.42' 
0.27 
2.09 
1.82 
Second foot_ 
.49 
1.65 
1.16 
.49 
1 . 66 
1.17 
.56 
1.42 
.86 
.52 
1. 59 
1.07 
Third foot_ 
.56 
1.14 
.58 
.57 
1.32 
.75 
.64 
.69 
.05 
.63 
.75 
.12 
Fourth foot____ 
.57 
.61 
.04 
.57 
.66 
.09 
.60 
.65 
.05 
.63 
.72 
.09 
Total crairi 
3. 06 
3. 53 
t" ' 1 
2.38 
3.10 
Gain hoi ow first foot L 
1. 78 
2.01 
nrrirrz 
.96 
1 . 28 
Rainfall during interval, in 
in oh 
5. 26 
5.26 
5. 30 
5.30 
1 
Soil section 
1922 
-1923 
3-year average 
Mulched, fall 
plowed 
Unmulched, 
stubble 
Mulched 
Unmulched 
Sept. 
7, 
1922 
Mar. 
23, 
1923 
Gain 
Sept. 
7, 
1922 
Mar. 
23, 
1923 
Gain 
Fall 
Spring 
L . 
Gam 
Fall 
Spring 
Gain 
/ 
First foot__ 
0.26 
1 . 21 
0.95 
0.25 
1.63 
1.38 
0.26 
1.48 
1.22 
0.25 
l 
1.83 
1.58 
Second foot.. 
.54 
1.15 
.61 
.52 
1. 57 
1.05 
.53 
1.41 
.88 
.51 
1 . 61 
1.10 
Third foot__ 
.61 
.60 
.01 
.64 
1.04 
.40 
.60 
.81 
.21 
.61 
1.04 
.43 
Fourth foot_,_ 
.57 
.60 
.03 
.63 
.49 
.14 
.58 
.62 
.04 
.61 
.62 
.01 
Total gaiD 
1.58 
2.69 
! 
I 
2.35 
3.12 
Gain below first foot. 
.63 
1.31 
, 
:. 
1.13 
1.54 
Rainfall during interval, in 
ino.hfis 
5.08 
5.08 
5.21 
5. 21 
1 
1 
I 
that had fallen between the dates of 
sampling. The mulched soil had ab¬ 
sorbed 3.06 inches during the same 
period, or 58 per cent of the total 
precipitation. Depth of absorption 
is an important factor in subsequent 
retention. In .the unmulched soil 2.01 
inches of moisture had penetrated 
below the first foot, while in the 
mulched soil 1.78 inches had reached 
this same lower level. The unmulched 
soil contained 12 per cent more mois¬ 
ture in the area where it could be most 
effectively retained. 
In the spring of 1922 the soil not 
mulched during the preceding winter 
had absorbed 3.10 inches of moisture, 
and of this amount 1.28 inches was 
below the first foot. The mulched 
soil in the same time had absorbed 
2.38 inches, with 0.96 inch below a 
depth of 1 foot. During this period 
the unmulched and mulched soils 
absorbed and retained, respectively, 
58 per cent and 45 per cent of the total 
precipitation. In total absorption, the 
unmulched soil was 30 per cent superior 
to the mulched, and in the amount 
penetrating below the first foot was 
22 per cent superior. 
In the spring of 1923 the data 
show that the unmulched soil had 
absorbed 2.69 inches of moisture in 
excess of that present the previous fall. 
Of this amount, 1.31 inches was below 
the first foot. The mulched soil 
absorbed 1.58 inches, with only 0.63 
inch at the lower levels. The data 
for the spring sampling of the un¬ 
mulched soil indicate that a loss 
occurred in the fourth foot of this 
treatment after soil moisture was 
determined the previous fall. This 
loss was due to weed growth (Russian 
thistle, Salsola kali tenuifolia G. F. W. - 
Mey) subsequent to the date of dry 
fall-plowing, and after the moisture . 
samplings were made. Despite this 
moisture loss from the unmulched N 
soil above that occurring from the 
mulched treatment, absorption was 
sufficiently greater where the mulch 
was absent to entirely recover this 
loss and with substantial additions in 
all sections except in the fourth foot. 
Total absorption in the unmulched 
