AN ffiCOLOGIOAL SURVEY OF THE MIDLANDS OF NATAL. 495 



3. Influence of Man. 



The high veld is the wattle region. The loose well-aerated 

 soil, with its high percentage of the higher oxides of iron, the 

 high rainfall and the frequent presence of mist-clouds, 

 is well suited for the growth of this tree (Acacia 

 mollissima). It is a tree which demands a great deal of 

 water, and the drainage is modified in the neighbourhood of 

 wattle plantations. Vleis are often completely dried up. 



The low veld is the mealie country. The mealie (maize) 

 demands a richer soil than that of the high veld, but when 

 the low veld soil is ploughed up and aerated it is found to be 

 very good for the growing of maize. Some farmers can raise 

 crops on the same soil every year, and get a good yield. 

 Others find that their soil requires artificial manures to obtain 

 an annual crop. Still others pursue successfully the fol- 

 lowing method. After one crop is obtained the soil is 

 ploughed up and allowed to remain fallow for either one or 

 in some cases two years, and it is then again cropped. This 

 practice is continued indefinitely. It is unnecessary in this 

 place to enter into the question of whether this is a case of 

 " soil exhaustion " or " soil sickness.^' At any rate there is, 

 as is to be expected, a good deal of variation in respect to 

 richness in chemical salts in the low veld soil. 



Of course the cultivation of the land leads to a complete 

 change in the vegetation, but there is much interest in 

 observing the various weeds (many of them exotic) which 

 come into such cultivated land, as well as the way in which, 

 if left alone, it reverts to veld. 



Though the direct influence of man is very great and 

 can be most easily seen, his indirect influence has been even 

 greater. 



During the last year or two, owing to East Coast fever, 

 few cattle have been kept in this district, but when great 

 herds of cattle roamed over the veld they affected both 

 vegetation and soil. The manner in which they influenced 

 the vegetation is of course obvious, but the effect on the soil 



