i 82 
Journal of Agricultural Research 
Vol. I, No. 3 
since the salt is more easily hydrolyzed than potassium chlorid, less sur¬ 
face energy being required to obtain potassium ions from solution, while 
the quantity of anions adsorbed will depend upon the specific properties 
of the anion employed. Also, if the anion of the salt is that of a weaker 
add than hydrochloric and is not adsorbed to a much greater extent than 
chlorin ions, a smaller amount of bases should be dissolved from the soil 
and a correspondingly greater acidity of the solution should result. 
Again, if a reaction is interposed so that the free acid will be used up 
before it has a chance to react with the soil particles—i. e., by adding a 
small amount of sodium hydroxid, yet enough to neutralize the acid 
theoretically set free—little or no dissolved bases of the soil should be 
found in the resulting solution. 
On the assumption that certain ingredients of the soil adsorb in part 
the base of a neutral salt in solution and that the free acid resulting from 
the hydrolysis caused by this adsorption reacts with certain of the soil 
particles and dissolves an almost equivalent amount of bases of the soil, 
the following experimental work is based. 
SERIES No. i 
In series No. i, 500-gram portions of a Durham sandy loam were intro¬ 
duced into a number of bottles of 2-liter capacity. To the first was 
added 2,000 c. c. of a solution containing 7.65 grams of potassium chlorid 
per liter; to the second 2,000 c. c. of a solution containing potassium 
acetate equivalent to 7.47 grams of potassium chlorid per liter; to the 
third 2,000 c. c. of water. The bottles were shaken frequently at room 
temperature for two days. The soil was allowed to settle until the 
supernatant liquid was apparently clear. Portions of the supernatant 
liquid were then pipetted off, filtered, and analyzed. 
The supernatant liquid from soil shaken with pure distilled water 
showed no appreciable presence of material dissolved from the soil, while 
the analyses of the supernatant liquids from soil shaken with the above 
solutions showed soil material present. The potassium-chlorid equiva¬ 
lents of the various constituents determined by these analyses are given 
in Table I. 
Tabi^k I .—-Adsorption by Durham sandy loam of potassium from solutions of potassium 
salts. 
[Results stated in grams of potassium chlorid per ioo c. c. equivalent to constituents determined 
by analyses.] 
Constituents by analysis. 
From 
KC 1 
solution. 
From [ 
CHaCOOK! 
solution, j 
| 
Constituents by analysis. | 
From 
KC 1 
solution. 
From 
CHaCOOK 
solution. 
K before contact. 
Grams. 
0. 7650 
.6950 
. 0107 
Grams . j 
O. 7470 
. 6560 
■ 0015 
Mg after contact. 
Grams. 
O. 0157 
Grams. 
O. 0167 
K after contact. 
Na after contact. 
A 1 after contact. 
Free acid after contact. 
. 0112 
. 0402 
Ca after contact. 
•0353 
• ° 3*4 
Anions after contact... 
• 7647 
•7450 
