1 6 president's address. 



is to say, the soil must be studied both absolutely and relatively. 

 Regarding the soil itself, we have to study its chemistry, its 

 physics, and its biology, the last including the indigenous vege- 

 tation on the surface as well as the micro-biology beneath the 

 surface. In respect of the soil's external relations, we have to 

 learn all that we can about the orography, the geology, and the 

 meteorology of the tract of country surveyed. Hence the soil 

 may be studied, as to its inherent qualities, in the soil laboratory 

 (though only after having been properly sampled) ; but as to 

 its external relationships co-operation with the surveyor, the 

 geologist and the meteorologist is needed. 



The whole subject of soil chemistry in relation to crop pro- 

 duction is comparatively little understood, not only in South 

 Africa, but all the world over. How little we know of it we 

 realise but too keenly when the world is faced with a wheat 

 shortage. All things are in a state of flux,* said Heraclitus, the 

 Greek sage, and he doubtless had a prevision of twentieth- 

 century science. It is little more than half a century ago that 

 the doctrine began to be preached that the crop-producing power 

 of a soil can be determined by a mere chemical analysis. There- 

 after arose a school that ridiculed such teaching, and upheld 

 practical plot experiments. To-day we find men like Patten 

 declaring that 



the manner of conducting fertiliser tests by measuring the crop produced 

 has failed to materially increase our knowledge of soil conditions, and it 

 is now quite generally recognised that it is unsafe to draw general con- 

 clusions from results based upon such experiments. + 



All this shows the need of agricultural chemical research, 

 for which South Africa affords a peculiarly well-adapted field. 



To come closer to particulars : the world has been threat- 

 ened with a wheat famine, and, second only to the problem of 

 munitions, there has come the wheat problem. On the day that 

 I left Australia — two months after the declaration of war — the 

 Commonwealth newspapers announced that the Government had 

 authorised the immediate conversion of large extents of forest 

 into wheat lands, and had set great bodies of men to work at 

 felling the trees. Of late we, too, have begun to show some 

 concern about our wheat crops, and the two problems that faced 

 us were how to make existing lands yield larger crops, and how 

 to extend the present wheat area. These problems have been 

 rendered none the easier by the extreme scarcity of fertilisers, 

 and with us, as, indeed, all over the world, the scarcity has 

 brought to the fore another problem — how to turn potential into 

 available supplies. These are all-important matters for research, 

 even in war-time ; in fact, all the more important because it is 

 war-time. 



Under war conditions, then, the cultivation of cereal lands 

 must of necessity be, as far as possible, intensive, and so we 

 need fertilisers containing not merely phosphates and nitrogen, 



* TIdvra pet- 



t Mich. Acad, of Science, T3th Report, (igii), 44. 



