The Relation of Subfur to Soil Fertility. 597 p
ferrous sulfate at the rate of 100 pounds per acre made the
. greatest gains in total nitrogen in every case and the greatest
gains in crop and total dry matter in nearly every case. As
a rule, the plot receiving 200 pounds of ferrous sulfate made
the least gain. The corn crop on the yplot receiving gypsum
at the rate of 1000 pounds per acre rnade gains in grain, dry
matter and nitrogen comparable with those made on the plot
receiving 100 pounds of ferrous sulfate. The other gypsum
plots either made only slight gains or yielded less than the
check plot. I
Reimerll has found on some types of soil in the Rogue
River Valley of Oregon, that the yield of alfalfa can be _
increased from 25 to 500 per cent by the use of either super-
phosphate or gypsum. Two plots were fertilized with
sulfur, one with iron sulfate; one with superphosphate and _
two with ground phosphate rock. The ground phosphate
rock gave no increase. The plots receiving sulfur, iron
l sulfate and superphosphate at the rate of 300 pounds per
acre, produced an increase of 100 per cent over the unfer-
tilized check plots. The plants on the fertilized plots were
greener, higher, thicker and freer from weeds.
. These results are of interest since analyses made at the
Wisconsin and Ohio Experiment Stations show that alfalfa
contains more sulfur than phosphorus. The latter Experi-
ment Station has shown that an average crop of alfalfa
contains 35 pounds of sulfur and 25 pounds of phosphorus
per acre.
‘ EXPERIMENTAL.
In the writer’s former publication was given a table of the
total sulfur in all the common feeding stuffs taken from the
. work of Hart and Peterson of the Wisconsin Experiment
Statim. In the table below are given the results of the
analyses of total sulfur made by the writer in some materials
which were not included in the former table. The sodium
- peroxide methodw was used in this work. ~