DEFART/V\ ENT OF AGRICULTURE. 



NEW SOUTH WALES. 



SCIENCE BULLETIN No. 9. 



The Relation of Fertilisers to Soil Fertility/ 



A SHORT SURVEY OF PRESENT VIEWS ON THE SUBJECT. 



F. B. GUTHRIE, Chemist. 



IN looking through previous volumes of the Association I find that the 

 addresses of my predecessors in the office to which you have done me the 

 honour to elect me, have dealt, without exception, with the broader aspects of 

 the connection of the State, or of this Association, with agricultural progress 

 or agricultural education. 



It seemed, therefore, more fitting that I should take as the subject-matter 

 of my address the development of some specific branch of agricultural science,, 

 especially as nearly everything I could say on the subject of agricultural 

 policy has been well said by my predecessors. An occasion like the present 

 appears a suitable one in which to pass in review the most recent advances made 

 in our science, as the presence of so many workers from the different States 

 renders it possible to discuss new developments from various points of view. 



A great deal of what I shall have to say probably all of it will not be 

 new to those of you who are engaged in scientific work in agriculture, and 

 have followed recent developments at all closely ; but there are, no doubt,, 

 many who have not the time nor opportunity to keep themselves posted in 

 the literature of the subject, to whom I trust a presentment of the matter 

 may prove of some interest. 



To all alike a review of what has been done in any given line of work 

 should stimulate discussion and be an incentive to further investigation. 



I purpose to review shortly the main lines along which recent work has. 

 been conducted regarding the relation of fertilisers to soil fertility. 



The trend of recent research in agricultural science has brought forcibly 

 home to us the fact that the function of fertilisers is not restricted to the 

 duty of supplying plant-food to the growing crop. Under certain circum- 

 stances, indeed, this function is in abeyance in the absence of sufficient 

 water, for example, or in the presence of unfavourable soil-conditions, the 

 action of fertilisers is almost negligible and it is our lack of understanding 

 of these conditions that has been the frequent cause of want of success in the 

 use of manures. 



The idea that failure in plant-production is due solely, or even chiefly, to- 

 deficient plant-food in the soil is no longer tenable. 



* Presidential address delivered before the Agricultural Section of the Australasian 

 Association for the Advancement of Science, Melbourne, January, 1913. 



