Dec. io, 1917 
Movement of Soluble Salts through Soils 
543 
In another series the tubes were stood upright, the upper ends being 
open in order to permit loss of water by evaporation and to thus deter¬ 
mine if the downward movement of the soluble material is appreciable 
when water is being lost in this manner. The results obtained and 
presented in Table XI show that the downward movement took place, 
the concentration of the solution being appreciably increased in the 
bottom layers of silt-loam soil, where 1 per cent of potassium chlorid 
was added, although the water content of the various layers was found 
to have decreased. It is possible that some of the soluble material in 
the lower layers would be translocated later on to the upper ones by the 
film water movement, this of course, could be determined by carrying 
on the experiments over a longer period. The greater concentration 
of the soil solution in the upper layers indicates an upward film move¬ 
ment of the water in this particular soil, of these water contents. We 
have experiments in progress which should show at what water content 
film movement ceases in different classes of soils. 
Table XI .—Movement of l per cent of potassium chlorid through silt-loam soil in open 
tubes , showing the concentration after 10 days 
Dis¬ 
tance 
from 
salt 
layer. 
Dow moisture. 
High moisture. 
Dow moisture. 
High moisture. 
Moist¬ 
ure 
con¬ 
tent. 
Moist¬ 
ure 
loss. 
Freez¬ 
ing- 
point 
lower¬ 
ings. 
Moist¬ 
ure 
con¬ 
tent. 
Moist¬ 
ure 
loss. 
Freez¬ 
ing- 
point 
lower¬ 
ings. 
L> 1 S- 
tance 
from 
salt 
layer. 
Moist¬ 
ure 
con¬ 
tent. 
Moist¬ 
ure 
loss. 
Freez¬ 
ing- 
point 
lower¬ 
ings. 
Moist¬ 
ure 
con¬ 
tent. 
Moist¬ 
ure 
loss. 
Freez¬ 
ing- 
point 
lower¬ 
ings. 
Inches. 
4 . 
2-93 
7. 88 
0.080 
« 
n -75 
6. 21 
O. 165 
Inches. 
1 . 
1 9.88 
0. 93 
0.125 
12.74 
5 .22 
O. 062 
3 . 
5. 68 
5.18 
.065 
95 
6. 01 
• 175 
2. 
9. 78 
1.03 
. 038 
12. 64 
5-32 
. 040 
2 . 
8-37 
2.44 
. no 
12. 21 
5 - 75 
. 172 
3 . 
9 - 93 
.88 
.045 
I2.95 
5- oi 
.058 
I . 
8. 85 
1. 96 
. 227 
12.30 
5- 66 
. 130 
4. 
10. 02 
•79 
. 060 
I 3 .OO 
4.96 
. 048 
0 . 
7 * 5 2 
2. 51 
. 270 
12. 00 
5-96 
. 098 
Where sand was employed, rather strikingly different conditions 
have ensued. It may be cited that, for example, according to the data 
in Table XII, the amount of soluble material that moved downward 
was indeed slight in comparison with the upper translocation, or with 
the downward movement in the silt-loam soil. It is evident from these 
results that soluble salts such as sodium nitrate when applied to sandy 
soils, or present in them, are more likely to be lost to the crop by their 
accumulation in the upper layers of soil during a drouth than they are 
in case of the finer-textured classes of soils. Field experiments now 
under way may afford additional evidence bearing on this question. 
