320 THROUGH ANGOLA 



Gregory finds that many of the soils of the 

 plateau are derived from granite, which gives 

 rise to a light, easily-worked soil, often rich in 

 potash, but generally poor in lime ; others, due 

 to sandstone, which is a granite debris without 

 plant food, he finds are still poorer ; while the 

 quartzite gives barren silicious soils, unless they 

 contain felspathic layers which enrich them. 



The soils of the gneiss rocks, rich in lime and 

 basic minerals, are found in the north and north- 

 west of Bailundo, while the fertile red or chocolate- 

 brown soils, produced from the igneous basic rocks, 

 are to the north and north-east of that town, at 

 Ochilesa, Chieuca, etc. With these richer soils 

 of the northern slopes of the plateau are associated 

 better prospects of irrigation from the deeper and 

 faster - flowing northern rivers than irom the 

 shallow sluggish streams in the southern slopes of 

 the plateau. It was the northern slope of the 

 Benguella plateau which Gregory recommended 

 for European colonization. 



The gentle slopes of these highlands, with 

 their deep soils where the rock outcrops but 

 rarely, and is generally covered to a depth of 

 6 to 10 feet, make ploughing easy and renders 

 tractor tillage specially suitable, except where the 

 N'goti vine is present. 



While Gregory does not regard the soil of 

 the Benguella highlands as of extreme fertility, 

 most of those examined by him and others, from 

 the Bai:Uiido and Caconda districts, have a good 

 reserve of plant food, and would improve with 

 competent cultivation. Lime is deficient from 



