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66 Tzveaty-niiufh Annual Report of the A
During the year daily bacterial counts have been made
of mill; from the Station dairy and from the Elmcndorf dairy.
YVe have also made baeteriological examinations of a number of
samples of water, tissues and other materials.
The investigation of the occurrence of sulfur in soils and
plants and its relation to permanent soil fertility has been t
continued by means of laboratory and pot experiments with soil  
samples representing some of our most important soil types.  
_ Pot experiments with clover, alfalfa, soy bean, wheat and oats,  
using powdered sulfur as a fertilizer, with calcium carbonate to  
correct acidity, gave favorable results for sulfur on three out of  
the eight types of soil tested. Analyses of the clover, alfalfa and  
W soy bean plants grown in these experiments show a decided in-
crease of the sulfur content of the plant, where sulfur was ap- i
plied to the soil. The analyses show, however, that this increase
is in the sulfate sulfur of the plant, except in the case of the
soy bean, in which the increase of sulfate sulfur accounted for
only a part of the increase in total sulfur, suggesting that other
forms of sulfur compounds had been increased. No increase in
nitrogen eontenti of the plants grown under sulfur fertilization
was observed. however.
A series of experiments was made to determine the loss of
sulfur in the process of drying vegetable material. llacerated
samples of cabbage and onions showed a gradual loss of sulfur
during air-drying at room temperature. A similar loss may be
taking place from living plants. during their growth.
A comparative study has been begun of the amount of
_ water-soluble phosphorus in cultivated and virgin soils and
considerable preliminary worl; has lreen done in finding a suitable
procedure. The conditions are t‘