The Relation of Subfur to Soil Fertility. 619 _
Jar. Substance Added. Pounds
- . , per Acre
N0. 16a Sodium sulfate, Na2SO.¤ s...e. r ..., rr., 221
" 16b " carbonate,?Na:CO:i ..ee wher,- at 165
" 17a Gypsum, CaSO.i2HzO-rr.   s...ees...e.._ 268
" 17b Calcium carbonate, CaCO:i ._ee..   ..ee 156
" 18 Flowers of sulfur, S _..ee.._.e..e . ...___ . 50
_ " 19 “ “ “ “r-.   ..e. .. ......e. 100
“ 20 “ “ “ “,.rr. .s..o..e... . .... 500
“ 21 “ " “‘ " ..eo.e.__.   sr_.es 1000
" 22a Check, nothing added but materials pre-
viously noted.
" 22b Check, nothing added but materials pre-
J viously noted.
In the jars from Nos. 1 to 10a, where sulfur compounds
were added, the amount of the element applied to each was
equivalent to 12 pounds per acre, while in the remainder, _
except where otherwise stated, it was 50 pounds per acre.
Twenty-five inoculated alfalfa seed were planted in each
 , jar and after germinating these were thinned to 20 average
size plants, and watered with distilled water.
The plants grew very well until they were about seven or
eight inches in height and then commenced to turn yellow. On
this account frequent cuttings were made about one inch from
the crown and cut at this stage, they continued to spread
, and had a good green color throughout the experiment.
As a rule, the plants in the jars containing the sulfur
compounds were larger than the checks, or those containing
the carbonates, but in a few cases, however, the reverse was
true. The air—dried weights of the different cuttings are
· given in the following table: