PRESIDENT] U. ADDRESS — SECTION Lt. -5 



holds for most of the Transvaal soils analysed. Nevertheless, on 

 comparing analytical data with actual field results, Mr. Ingle 

 remarks : 



" An English analyst would be inclined to condemn the soils as of poor 

 quality. Yet in many cases such soils prove of great fertility, and yield 

 abundant crops." 



The plain fact that stands out clearly from the work that has so 

 far been done is that in South Africa we have still to ascertain 

 the standards of sufficiency of plant food. All the analyses (of 

 about i. 200 soils) that have so far been made supply only a small 

 part of the information needed by the soil analyst before he can 

 arrive at standards or " types " on which to base advice of practi- 

 cal value to farmers. It is not sufficient for the farmer to know 

 that his vineyard, say, needs lime as well as other fertilizers to 

 increase the acidity in his grapes, and so ensure proper fermenta- 

 tion of the juice, although this alone is something worth knowing. 

 The farmer needs to know //ore much lime exactly is needed, con- 

 sistent with economy and the best results. Again, it is not suffi- 

 cient for the farmer to have the chemical analysis of the surface 

 soil 12 inches deep. What cultivated plant in South Africa, 

 where the surface soil may be baked by a semi-tropical sun, is 

 independent of the soil below a depth of 12 inches ? And yet 

 most of the 1.200 soil analyses referred to above take no account 

 of the subsoil. 



No one is more conscious of the need for more extended 

 work than are those whom we have to thank for the pioneer 

 investigations already accomplished. Dr. Juritz has been able to 

 trace some important relations between certain groups of soils 

 and the geological formations from which they have been derived 

 This constitutes the first attempt at distinguishing " soil types " 

 in South Africa. Pie has himself earnestly pleaded the need of 

 further investigations again and again, and it appears to me a 

 matter of great urgency that Dr. Juritz should be placed in a 

 position to develop and extend the important work in soil analysis 

 which he has carried on under adverse circumstances for a num- 

 ber of years. 



In South Africa, where geological formations exhibit a cer- 

 tain sameness of character over considerable areas, it is not 

 surprising to find that there are widespread soil deposits which, 

 speaking broadly, show a corresponding uniformity. Thus geo- 

 logical considerations must play an important role in the matter 

 of discriminating distinct types of soil. On p. 158 of his book 

 Dr. Juritz shows that a number of soils on the Malmesbury Beds 

 exhibit an all-round poverty in plant-food, with an average for 

 all the soils as follows: — Lime, .079 per cent.; potash, .124 per 

 cent. ; phosphoric oxide, .039 per cent. Whereas, if tzvo of the 

 soils from the farm Hooge Kraal be omitted, the average falls 

 to .039 per cent, of each of these constituents. These two excep- 

 tional soils show : Lime. .358 per cent. ; potash, .719 per cent., 

 and phosphoric oxide. .041 per cent. 



