PROCEEDINGS OF SECTION K. 66] 



Infertile conditions, whether due to soil-bacteria, fungi, or the 

 formation of poisonous chemical substances, will be combated by the 

 same weapons as are now employed against similar diseases in men 

 and animals. 



Whilst there is no intention on my part in all that has gone be- 

 fore to suggest for a moment that we should cease to manure with 

 the recognised fertilizers, potash, nitrogen, and phosphates, or that 

 we should cease to conduct experiments into the best proportions of 

 these manures for different crops, still I feel that future progress 

 in this matter lies more with actual farmers' experiments where 

 the principles already established by careful scientific investigation 

 can be tested and modified to suit actual conditions. I feel that the 

 time occupied in elaborate manure experiments on the old lines, 

 and in the elaboration of methods of soil-analysis on the old lines, 

 would be better spent in the study of other factors productive of 

 soil fertility or infertility, such as some that I have outlined above, 

 and I hope that it may be possible for some of our Australian 

 workers to devote more time to plant physiology, to the study of 

 soil toxins and the elucidation of conditions which render the soil 

 fertile or infertile, whether physical, chemical, or micro-biological 

 in fclieir nature. 



1. THE INFLUENCE OF PHOSPHATIC FERTILIZERS ON 

 ROOT DEVELOPMENT. 



By Professor R. D. Wait, M.A., B.Sc, University of Sydney. 



The beneficial effect of a readily available phosphatic fertilizer 

 such as superphosphate on most crops, especially in the early stages 

 CI their growth, has long been known to agricultural chemists and 

 practical farmers. From time to time the opinion has been ex- 

 pressed that this is partly due to their stimulating effect on the root- 

 development of the young plants; though, so far as the author has 

 been able to ascertain, no direct experimental evidence has been 

 forthcoming. Almost the only published reference to the subject 

 appears to be in a paper on " Turnip Culture " by the late Sir 

 John Lawes, Bart., in 1847, in which he states that — 



" Whether or not superphosphate of lime owes much of its 

 effect to its chemical action in the soil, it is certainly 

 true that it causes a much enhanced development of 

 the underground collective apparatus of the plant, 

 especially of lateral and fibrous roots." 



