SULPHUR AND NITROGEN CONTENT OF ALFALFA 
GROWN UNDER VARIOUS CONDITIONS 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 
d EE. Ho Rare 
Introduction 
Various investigators show a considerable variation in the 
analyses of the sulphur content of alfalfa, as well as in the proportion 
of organic and inorganic sulphur in the crop. It was thought well 
to analyze alfalfa from a number of selected places to see to what 
degree these variations could be explained by different sources of 
the crop, and to what degree by the personal factor of applying the 
none too reliable fusion methods, which probably always involve 
more or less volatilization and loss of sulphur. The very extensive 
Oregon work (11) has shown that the acre yield of alfalfa is enor- 
mously increased on their plats by the application of any sulphur 
source, and that on the fertilized plats the alfalfa contains a very 
much higher percentage of protein. Determinations were made in 
each sample of the total and nitrate nitrogen in order to ascertain 
whether there is any correlation between the sulphur and nitrogen 
content of alfalfa from the various sources. 
It has been long established that sulphur is one of the ten 
essential elements for the growth of plants. This is easy to under- 
stand when one recognizes that sulphur is an essential building 
material for all plant proteins, as well as for various odor and flavor 
producing organic compounds found in members of the mustard 
family, onions, etc. While much of the sulphur in plants is found 
in the form of these organic compounds, there is also some inorganic 
or sulphate sulphur present. The latter is generally considered 
an excess of absorption of sulphur over its utilization. It may be, 
however, that some free sulphate sulphur must be present as a 
building material in order to insure maximum protein synthesis 
and maximum growth. ScHERTz found that in the older leaves of 
Coleus Blumei some free nitrate must be present as a building 
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