AGRO-GEOGRAPHICAL CONDITIONS IN SOUTH AFRICA. 11 



Province as far as Cape Agulhas and in which the precipitation 

 is of a less torrential character than in the remaining areas. 

 Here the rainfall is more effective, since the loss from evapora- 

 tion is less because of the relative low temperatm'es found in 

 winter. (2) The all-the-year-round area, which includes the 

 coastal section from Agulhas to Port Alfred. (3) The summer 

 rainfall area, which includes the coastal parts east of Port 

 Alfred as well as the plateaux inland. The agriculture prac- 

 tised in these three areas is necessarily directly related to the 

 seasonal rainfall. ' In (1) winter crops, in (2) summer and 

 winter crops — though neither are very assured because of the 

 torrential character of the rainfall — and in (3) summer crops 

 are those which are most successful. Based on the average 

 annual precipitation in the summer rainfall area, crops without 

 irrigation are roughly successful as follows : — 



Rainfall. Crops. 



45 inches and above. Sugar-cane. 



24-45 inches. Practically all common summer field 



crops. 

 20-24 inches. Peanuts, cotton, sorghums, millets 



and sunflowers. 

 15-20 inches. Fodder crops such as Sudan grass and 



millets. 

 5-15 inches. Saltbushes, prickly pear, Mexican 



aloe, Prosopis juliflora, etc., i.e., 



perennial fodder trees and shrubs. 



The cultivation of crops is rapidly becoming demarcated 

 and characterised for the different rainfall zones, and doubtless 

 will become more marked as experience of our conditions in- 

 creases. Kunning from east to west up to the 24-inch isoheyt 

 (isoheyt, an imaginary line connecting places which have an 

 equal annual rainfall), summer grain growing is reasonably 

 secure and the favourable precipitation has permitted the in- 

 auguration of more intensive farming. Thus on the high veld 

 of the north-eastern Free State and the Transvaal, in East 

 Griqualand and Natal, besides crop cultivation, dairy, pig, 

 poultry and fruit farming are increasing markedly. 



Between the isoheyts of 20 and 24 inches we find grain 

 farming as the chief feature of agronomy is fast being sup- 

 planted by the cultivation of the more drought resistant cereals, 

 i.e., flint maize, grain sorghums and fodder crops. 



