66 4 
Journal of Agricultural Research 
Vol. XI, No. 12 
Table IV .—Ratios between total calcium oxid and iron oxid and aluminium oxid 
soils —Continued 
alkaline soils 
Laboratory No. 
Iron oxid. 
Aluminium 
oxid. 
Iron oxi d 
4 -Alumin¬ 
ium 
oxid. 
4. 82 
A TO 
9 - 55 
6. 05 
8. 19 
4.40 
a 0 r% 
14.37 
10. 24 
10. 75 
6- 57 
13. 68 
11. K2 
9.46 
7 - 23 
to St 
4. ±9 
<y eft 
O T 1 
8. 
I 7 
4 . 46 
3-58 
2. 66 
2. 26 
A *10 
11 . 
7.94 
ft 
u« 00 
4. 97 
18. 
4 * i* 
2 2ft 
o* oy 
7.04 
^ft 
12 . OI 
10.43 
O' 69 
T A A 
1. 44 
0 to 
O' 7 ° 
6. 90 
6. 68 
5.20 
9.40 
8. 77 
0 on 
While these results show that, in general, the total quantities of cal¬ 
cium and aluminium are lower and the total quantities of iron higher in 
the acid than in the alkaline soils, there is no distinct relationship be¬ 
tween these total quantities and the soil reaction as there is in the case 
of the acid-soluble portions. 
Total sulphur and magnesium were determined also, but no relation¬ 
ships were found between these elements and the soil reaction. The 
largest quantity of magnesium found in an acid soil was 3,226 pounds 
per 2,000,000 pounds of soil, and for an alkaline soil 4,288 pounds: con¬ 
sequently these soils may be characterized as low in magnesium. 
As stated before, the acid-soluble silica was determined and these 
results, together with the “lime requirement” of the acid soils de¬ 
termined by the Veitch method, are given in Table V. A certain but 
not well-defined relationship exists between the quantities of acid- 
soluble silica and the “lime requirement.” No other relationships 
concerning acid-soluble silica were discovered. 
