CHAPTER XIII 

 PLANT INDUSTRY 



SHIFTING CULTIVATION! 



SHIFTING cultivation may be defined as any form of agriculture 

 in which a patch of ground is cultivated for a short period of 

 years until the soil shows signs of exhaustion or the land is overrun 

 by weeds, after which the land is left to the natural vegetation 

 while cultivation is carried on elsewhere. In due course the original 

 site is usually planted again after the natural growth has restored 

 fertility and checked the weeds of cultivation. This is the method 

 followed by native tribes throughout the more densely vegetated 

 parts of Africa. Two main types of shifting cultivation can be 

 recognized: one in which the population moves to new quarters 

 at frequent intervals, as new areas of forest are felled and brought 

 into cultivation, and the other in which the people remain in fixed 

 villages and open up new land within reach of the old habitations. 

 The latter is essentially a rotational method which forms a per^ 

 fectly sound basis for the introduction of improved methods of 

 cultivation to avoid the dangers of soil deterioration. 



After a long period of shifting cultivation the whole character 

 of the vegetation may be altered beyond recognition. In countries 

 with an equatorial climate, without a dry season, shifting cultiva- 

 tion usually changes virgin forest into secondary forest and thence 

 to a kind of bush vegetation. This can be observed round every 

 native village in the rain forests of the Congo or the Guinea lands. 

 In regions with a marked dry season the usual effect is to change 

 evergreen forest into deciduous forest and thence to a kind of park- 

 land which resembles savannah, but in special circumstances quite 

 different conditions may result. In Uganda, for example, there 



^ See also chapters V and VII. 



