^VrRY ho 
Vol. LXXI. No. 4174 
NEW YORK, OCTOBER 26, 1912 
WEEKLY, $1.00 PER YEAR 
SULPHUR AS A FERTI¬ 
LIZER. 
New Ideas in Plant Feeding. 
Remarkable discoveries re¬ 
garding the use of sulphur as 
a fertilizer have been made 
both in Europe and America 
during the last two or three 
years. Since the articles tell¬ 
ing of these new ideas have 
been published' in technical 
journals not accessible to the 
average man interested in 
agriculture, it seems worth 
while to gather the important 
facts together so that they 
may be available to the prac¬ 
tical agriculturist. 
The work of E. B. Hart 
and W. H. Peterson of the 
University of Wisconsin will 
first be considered, as it is in 
many respects the most im¬ 
portant. These men, while 
investigating the supply of 
sulphur in feeds and its re¬ 
lation to wool production, 
found it necessary to deter¬ 
mine the amounts of sulphur 
in common crops used as 
feeds. Their determinations 
showed such startling discrep¬ 
ancies from Wolfe’s tables 
and other standard sources 
as to the amounts of sulphur 
found in plants that they 
made a thorough investiga¬ 
tion of the subject. 
The reason for the errors 
has long been recognized, but 
it has not generally been be¬ 
lieved that they were of suf¬ 
ficient importance to need any 
special attention. This is not 
the case, however; the errors 
were so large as to com¬ 
pletely change the status of 
sulphur as a plant food, and 
now this element must be 
considered with potash and 
phosphoric acid, the other 
essential elements which oc¬ 
cur in large quantities. 
Formerly when the amount 
of sulphur in a plant was to 
be determined the plant was 
ignited and the sulphur in 
the ash was reported as the 
amount of sulphur in the 
plant. Sulphur, however, in 
certain forms is volatile, and 
when exposed to a high heat 
is driven off in a gaseous 
form and lost. In this way 
we secured our wrong ideas 
regarding the importance of 
sulphur in plants. It is con- 
ceded by all agricultural 
chemists that sulphur is ab¬ 
solutely indispensable to the 
growth of plants; they did 
not suppose that it was re¬ 
quired, except in extremely 
BELLE OF GEORGIA PEACHES AT HOPE FARM. Fig. 447. 
small amounts, hence the 
common statement that the 
soil already contains plenty 
o f sulphur for the crops. 
Hart and Peterson went at 
the problem in a different 
way. They found the sul¬ 
phur in the air-dry plant by 
a modern method of analysis. 
This prevented the losses 
caused by ignition and gives 
us our first reliable informa¬ 
tion on the subject. 
A few extracts from a table 
prepared by them will prob¬ 
ably give the practical man 
the clearest idea of the im¬ 
portance of their discoveries. 
(See table next page.) In 
the first column we have the 
pounds of sulphur which 
would be removed per acre 
according to the standard au¬ 
thorities previous to 1911. 
The second table shows the 
amounts of sulphur actually 
removed, and the third the 
amounts of phosphoric acid 
removed per acre. The last 
table shows the relative im¬ 
portance of sulphur and 
phosphoric acid. The compari¬ 
son is surprising in its results. 
It is seen at a glance that 
sulphur in special plants such 
as Alfalfa, turnip and cab¬ 
bage is greatly in excess of 
phosphoric acid, and in all 
cases it occurs in large quan¬ 
tities. Not only is this the 
case, but sulphur is not more 
abundant in the soil than 
phosphoric acid, what is 
gained by rainfall being lost 
by drainage. From these 
facts it is evident that if it 
is necessary to add phosphoric 
acid to the soil, it is also 
necessary to add sulphur. 
This has been done uncon¬ 
sciously to a certain extent, 
since superphosphates and 
gypsum, also ammonium and 
potassium sulphates, all con¬ 
tain sulphur. These fertiliz¬ 
ers were not used on account 
of the sulphur contained in 
them, however, but for other 
reasons. The new facts con¬ 
cerning sulphur help to ex¬ 
plain the beneficial action of 
some of these substances as 
compared with others. It is 
suggested that the difference 
may be due more to the sul¬ 
phur than the difference in 
solubility, as formerly sup¬ 
posed. Hart and Peter¬ 
son naturally concluded 
as a result of their investiga¬ 
tions that sulphur must be 
systematically added to the 
soil in order to secure a ra¬ 
tional system of fertilization. 
