Studies on land use in Africa have usually been carried out by ethnologists or human geographers and were rarely concerned with data on the physical conditions of soil. There is hardly any issue, however, where interdependencies between natural and cultural factors are as evident as in the topic of land use. For this project the approach of three ethnologists, Braukämper, Kirscht and Platte, was therefore combined with the analysis of Thiemeyer as physical geographer. The area of research is the Local Government Area of Marte in the Nigerian State of Borno. As part of the Chad Basin this region is mainly characterised by clay sediments which are commonly labelled firgi by its inhabitants. Beside this general term, however, the local peasants clearly distinguish five types of soil (Kanuri: katti), to which different physical conditions and qualities with respect to their cultivation are attributed. The question arose how far can this popular knowledge, accumulated by agricultural experiences over generations, be correlated with scientific data. That is why samples of the mentioned types of soil were collected by the members of our team and analysed in the laboratory of the Frankfurt Institute of Physical Geography. The detailed presentation of this analysis has to be preceded by the classification of the respective soil types in the terminology of the indigenous farmers.