LIMING OF SOILS FROM A PHYSIOLOGICAL STANDPOINT. (19 
In most of the very fertile a//uvza/ soils of Louisiana the amounts 
of lime and magnesia are nearly equal, and only in three cases out of 
twelve (subsoils included) is there an undue preponderance of mag- 
nesia. | 
Soils of various States and sections.—As to Florida, North Caro- 
lina, South Carolina, and Georgia, and some States of the arid regions, 
a review on the composition of soils by Hilgard’* was consulted, and 
the average ratio of lime to magnesia calculated from these data, as 
follows: 
Ratio of lime to magnesia in certain soils. 
Ratio of 
States. lime to Range of percentage. 
magnesia. 
Lio Pis (0! Veet = See ee ne ae 1:0. 30 
| North Carolina 2.2 esses 1:0.91 |0.07 to 0.14 per cent lime. | 
rsa ene <2 oh SS, sh. as 21.09 ore to 0.15 per cent magnesia. | 
' 
(SECT SSE oe ee OO a ee 30 
JESUS ora Nae Sie OR 2 ar) ae, Se | 
SES a Rg ee Bp eee 1 to 2 per cent lime. 
CIS wer: Game es Sat yk ee a 
a oe ee 
coor fe 
x 
S) 
:0.60 |1to1.5 per cent magnesia. 
4 Ete i ee RS ee a ee 
The soils of the arid regions of the four last-named States contain 
much more lime and magnesia and also more potassa and soda than 
the soils of the four first-named States of the humid regions, while the 
differences in the contents of phosphoric acid, sulphuric acid, and 
ferric oxide are not so marked. It must be pointed out, further, that 
Hilgard omitted intentionally all typical calcareous or limestone soils 
from consideration. 
A comparatively small number of soils of Arizona, Utah, New Mexico, 
and Colorado have thus far been analyzed, but. in most of these cases 
lime preponderates over magnesia. In Bulletin No. 33 of the Colorado 
Agricultural Experiment Station are mentioned five analyses of soils of 
which two show more magnesia than lime, and in Bulletin No. 9, of 
the same station, are mentioned analyses of soils from seven different 
localities, of which only one shows more magnesia than lime. The 
excess of magnesia over lime in these three cases is but small. In the 
last mentioned seven analyses the maximum of lime is 3.69 per cent, of 
magnesia 1.61; the minimum of lime is 0.68, of magnesia 0.54 per cent. 
Of Utah soils, six samples were analyzed from Sanpete County’ 
which show from 8 to 22 per cent of lime and only 0.13 to 1.8 per 
cent of magnesia. Of seven specimens of soils from Clarke County, 
none contained more magnesia than lime, the maximum of lime being 
1A report on the relation of soil to climate, by E. W. Hilgard, U. S. Dept. of Agr., 
Weather Bureau Bul. No. 3, Washington, 1892. 
* Agr. Exp. Station Bul. No. 52, Logan, Utah. As to Arizona soils, some analyses 
are contained in Bul. No. 28 of the Agr. Exp. Station of Arizona. 
