9 
THE JOURNAL 
OF THE 
NATURAL HISTORY & SCIENCE SOCIETY 
OK 
WESTERN AUSTRALIA. 
VOL. IV. 
Summer Temperatures of the Soil in Relation to 
the Supply of Available Nitrogen in the Wheat 
Areas. By W. Catton Grasby, F.L.S. 
(Read February 14th, 1911.) 
ABSTRACT. 
(Printed in full in the West Australian, February 
17th, 1911.) 
The importance of combined nitrogen as a plant food 
could not be over-estimated, it being the most costly of all 
fertilisers, but it was an interesting fact that in connection 
with wheat growing in Australia, the use of nitrogenous 
fertilisers had proved to be so far unnecessary. The soil 
was not an inert dead substance, merely consisting of de- 
composed rock, for it owed its fertility very largely to the 
organic matter it contained, which supported a prolific 
microscopic flora and fauna. It had been known for a 
considerable time that heating soil to a temperature sufficient 
to partially sterilise it resulted in a wonderful increase in 
productiveness, and this knowledge had been made use of 
by nurserymen in preparing soil for raising seedlings. The 
reason for this remarkable result was investigated by 
J)rs. Russell and Hutchison, and the results of their in- 
vestigations were contributed to the “ Journal of Agri- 
cultural Science ” for October, 1909. The researches of 
these gentlemen showed that they found that soil which 
had been treated to a process of partial sterilisation, either 
by heat or by an antiseptic, was characterised by an ex- 
ceptional accumulation of ammonia. They also discovered 
that, contrary to accepted opinion, plants were capable of 
absorbing and utilising nitrogen in the form of ammonia 
and that this increase in nitrogen was sufficient to account 
for the added fertility. The researches also disclosed the 
act that the partial sterilisation was associated with the 
