104 
Journal of Agricultural Research 
Vol. 26, No. 3 
EXPERIMENT 14.—acid-treated soil+calcium hydroxid. (soil low in calcium.) 
One hundred gm. of soil, Oswego silt loam, were placed in a 2-liter 
glass-stoppered bottle and 2 liters 0.5N HC1 added. The bottle was 
shaken for a while, and the contents were then allowed to digest for sev¬ 
eral days with occasional shakings. The soil was washed by decanta¬ 
tion as long as it would settle clear, and finally washed on a Buchner funnel 
until the filtrate gave a neutral reaction to litmus. The soil was then 
dried and used in a manner similar to that of Experiment 5. The data 
obtained are given in Table XIV. 
Table XIV.— Ph of suspensions of acid-treated soil-{-Ca(OH) 2 , also titrations and calcium 
content of extracts and calcium adsorbed from soil. (Soil low in calcium.) 
Calcium added. 
Suspension. 
0.05N HCl. 
Calcium in 
extract. 
Calcium not 
adsorbed. 
Calcium 
adsorbed. 
Mgm. 
Pn 
Cc. 
Mgm. 
Mgm. 
Mgm. 
8. 
3 - 70 
-i *3 
I. O 
I. O 
7.0 
4-85 
-.6 
I. 2 
I. 2 
14. 8 
6. 24 
. 0 
2.8 
2. 8 
21.a 
36 . 
7-35 
•4 
3-4 
3-4 
32.6 
48 . 
8.98 
.6 
4-5 
4-5 
43 -S 
9. 42 
2.3 
8. 1 
8.1 
51-9 
80. 
9. 72 
3-4 
10. 8 
10. 8 
69. 2 
The acid treatment greatly increased the hydrogen-ion concentration 
of the suspension. The small value of the titration figures in comparison 
with the figures for the amount of calcium in the extract indicates that 
most of the calcium was present in the form of a neutral compound. 
The ratio of the amount of calcium adsorbed in relation to the amount 
added was as great with an addition of 80 mgm. calcium in the form of 
Ca(OH) 2 as with 8 mgm., indicating that the adsorptive capacity was 
not reached. In view of this, the greater amount of calcium found in 
the extract was probably due to resolution of an adsorption compound 
of calcium. 
EXPERIMENT 15.—ACID-TREATED SOIL-{-CALCIUM HYDROXID. (SOIL HIGH IN CALCIUM.) 
The procedure in this experiment was the same as that in Experiment 
14, except that the soil used was a Summit silt loam high in calcium. 
The data obtained are given in Table XV. 
Table XV. — Ph of suspensions from acid-treated soil , also titrations and calcium content 
of extracts and calcium adsorbed from Ca(OH) 2 
Calcium added. 
Suspension. 
0.05NHCI 
Calcium in 
extract. 
Calcium not 
adsorbed. 
Calcium ad¬ 
sorbed. 
Mgm. 
Ph 
Cc. 
Mgm. 
Mgm. 
Mgm. 
8. 
3-36 
— i. 6 
O. 7 
O. 7 
7-3 
3-43 
— 1. 0 
I. O 
I. O 
15 - 0 
24. 
3. 80 
— 1. 2 
I. 2 
I. 2 
22. 8 
4 * 3 1 
— 1. 0 
1.8 
1. 8 
34 . 2 
48.. 
5 - 77 
-•4 
2. I 
2. I 
45 * 9 
7 - 35 
-. 4 
5 - 1 
5 - 1 
54*9 
80 . 
8. 47 
-•5 
8.8 
8.8 
71 - 
