Soil spatial heterogeneity is inherent to smallholder African agriculture. It originates from the interaction between geological and geomorphological diversity across landscapes and the effects of land use and management over time. Several studies have documented the causes and impacts of soil heterogeneity on crop productivity in sub-Saharan Africa in the last decade (e.g., Tittonell et al. 2005a,b; Samaké et al. 2005; Mtambanengwe and Mapfumo 2005; Nkonya etal. 2015). A common denominator in these studies is the fact that limited resource availability leads to concentration of organic matter and nutrient inputs in certain areas of the farm or agricultural landscape, resulting in coexisting areas of net accumulation and areas of net depletion. The latter are often more extended than the former. In certain regions, heterogeneity may be created as a strategy to increase resource use efficiency, diversify, or spread risks. Yet in many areas of sub-Saharan Africa, notably in sparsely populated regions, soil heterogeneity may not conform to this specific spatial pattern. This may be the case where particular forms of shifting cul-tivation still prevail, in sparsely populated regions where no agriculture inputs are used, where perennial crops are the dominant land use, or where physical landscape units are strongly associated with particular forms of land use and management as in the case of irrigated rice cultivation.
DOI:
https://doi.org/10.1201/b18759-12Altmetric score:
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Publication year
2022
Authors
Tittonell P; Van Dis R; Vanlauwe B; Shepherd K D
Language
English
