Mats Widgren has announced on H-Africa the forthcoming publication of a new map of agricultural systems in sub-Saharan Africa to 1800 in:
Widgren, Mats. (in press) “Agriculture in sub-Saharan Africa by 1800: a map and a gazetteer.” In Mercuri, A.M., D’Andrea, A.C., Fornaciari, R., Höhn, A. (eds.). Plants and People in the African Past – Progress in African Archaeobotany, Springer.
The map, references to the map, and GIS-files can now be downloaded from: https://doi.org/10.17045/sthlmuni.5173477
Abstract of chapter: Recent global historical cropland modelling grossly underestimates the pre-colonial development of agriculture in the Americas and many parts of sub-Saharan Africa. Such models are usually developed from backcasting from recent land cover combined with environmentally deterministic algorithms. Historical geographers have been slow in responding to this new demand for a global synthesis. Here a preliminary map of African agricultural systems by 1800 AD is presented. It forms part of the project Mapping Global Agriculture and is based on the existing historical literature, observations by early travelers, archaeology and archaeobotany. Its preliminary nature must be emphasized.
The GIS-files can be opened with GIS programmes such as QGIS (open source) or ArcGIS. Note that they have to overlayed with coastlines (and lakes, depending on scale). If you use the data: please refer to the article.