824 



Journal of the Department of Agriculture. 



Since the general reader may find it somewliat difficult to follow 

 figures, Table IX has been compiled in which, in place of figures, the 

 terms " fair," " good," and so on have been used. 



Table IX. 



Sandbult Type. 



Mixed Sand and 

 Turf Tj'pe. 



Black Turf 

 Type. 



Fertility 



Colour .. 

 Situation 



Organic content 



Clay and silts ... ... 



Sands 



Permeability 



Retentiveness ... 



Plant food 



Crops found most suitable 



Very low 

 Reddibh brown 

 Bults I 



Low 



Rather low 



Very high 



H'gh 



Fair 



Low 



Oats and rye 



Very fair 

 Daik brown 

 Lower slopes of 

 mountains, etc. 

 Jledium 

 Medium 

 High 

 Medium 

 Good 

 Fair 

 Potatoes and wheat 



High 

 Black 

 Vleis, kloofs, and 



valley bottoms 

 High 

 High 

 Medium 

 Fair 



Veiy good 

 Good 

 Wheat 



The soils which are the most fertile are evidently those which, 

 owing to their high proportion of humus, are black in colour and 

 which contain a good amount of plant food and considerable quantities 

 of clay and silts ; all of which points to the utility of the laboratory 

 investigation of the soil. 



The reddisli brown soils are without exception highly permeable 

 to water and only fairly retentive ; they lack humus and are poor all 

 round in plant food. In the experience of the farmer they are very 

 poor crop producers. Again the experience of the farmer and 

 laboratory investigation are in agreement, as is also the case with the 

 mixed dark brown type. In this connection the writer would like to 

 express the opinion that laboratory investigation, based on careful 

 work in the field, is of much assistance to farmers ; that it is only 

 where the field work (as, for instance, the sampling which, in the 

 writer's experience, the average farmer is not good at, notwith- 

 standing clear v/ritten instructions) has not been properly done that 

 analytical methods are likely to fail. 



So far we have only alluded, liere and there, to the influence of 

 geological origin on the fertility of the soil. Nothing very definite 

 can be said on this point, but it is obvious from Table VII that the 

 best soils are those in the formation of which there would appear to 

 have been lava or doleritic influence. The nearer the volcanic beds 

 or dolerite the better are the soils. In this connection the following 

 is of interest with reference to the sale in portions of a Witkop farm. 

 The portion of the farm on which there is a large mass of volcanic 

 beds was sold for £13. 15s. per morgen ; lower down, where the soils 

 overlie Molteno beds, but are doubtless still subject to lava influence, 

 the price fetched was £11 per morgen ; lower down still the price 

 dropped to £8 per morgen. 



The record of the vegetation given in Table VII is perhaps not 

 very complete but is the best the writer could do unaided by a 

 botanist. From the data therein set down it would appear that the 

 best soils are those which carry the greatest variety of plants; that 



