207 



be caused by other factors than the lack of plant food in 

 the soil has been shown more "han once in these page, so 

 that there is no need to labour the matter further; and in many cases 

 where there is no question of barrenness at all, the difference of texture 

 in soils suited, say, to the cultivation of potatoes, and soils of a more 

 clayey nature, has exercised a controlling influence upon the class of farm- 

 ing to be practised; such differences of texture in the soil profile may be 

 actually mapped out, and would afford a means of incalculable benefit. It- 

 has, for instance, been seen that to a certain extent geological influences 

 perform an important part in this connection (see p. 195) and, placing 

 this over against what has been referred to above regarding the mapping 

 out of soil types, it becomes evident that an interesting and most valuable 

 phase of the subject invites closer study. Hitherto the study of the soil's 

 physical condition has extended little beyond the mechanical analyses of 

 more or less typical soils of three broad classes, namely, the grain soils 

 of the south-western districts, the fruit and general farm soils of the Wor- 

 cester-Robertson area, and the deposited silts of the Orange River, all of 

 which have been dealt with under the head of " Physical composition of 

 soils." A far wider application of this branch of investigation should now 

 be embarked upon. 



From a chemical point of view the richness of the soils where the 

 Bokkeveld series and the Karroo system prevail has been shown, nob to 

 mention the chemical value of the river silts, the products of the erosion 

 that is going on elsewhere; and the efforts to retain and utilise these 

 latter also deserve extended application as a matter of economic import- 

 ance. 



In these and other respects, briefly and inadequately touched upon 

 hitherto, and in many more as yet untouched, which need not be specially 

 mentioned here, but will occur at once to anyone reading the foregoing 

 records and acquainted with the state of agricultural science to-day, the 

 practical value of a soil survey to this vast and fertile country is immense, 

 and all the more is it important at this juncture, when a general re- 

 awakening to the need of agricultural development is manifesting itself, 

 and when it is beginning to be more thoroughly realised how great are 

 the capacities of this sub-continent for such development, and for taking 

 full advantage of the magnificent climate wherewith it has been endowed. 



I must not conclude without some words of acknowledgement of the 

 services of those gentlemen who, as members of my staff, have from time 

 to time individually undertaken many of the analyses which have enabled 

 me to compile this record. Although most of the work detailed under the 

 heads of " Alkalinity " and " Physical composition " was carried out by 

 myself in person, of the analyses enumerated in Part III. opportunity was 

 not afforded me, for the reasons already explained, of performing more 

 than about eighty. My especial acknowledgments are due to Mr. A. 

 Simons, B.A., who performed over 400 analyses. The services of the late 

 Mr. J. C. Watermeyer, and of Messrs. J. Muller, B.A., and St. C. O. 

 Sinclair, M.A., who undertook some 60 analyses each, are also entitled to 

 special recognition here. Without the valued aid of these and the other 

 members past and present of the laboratory staff, this compilation could 

 not, for lack of material, have been undertaken. My thanks are also due 

 to my brother, Mr. J. W. Juritz, for his ready assistance in drawing the 

 maps with which this record has been illustrated. 



