In this brief we examine the environmental constraints to, and impacts of, smallholder sorghum and millet production systems in Sub-Saharan Africa (SSA) and South Asia (SA). Millet in this paper primarily refers to pearl millet (Pennisetum glaucum), although a number of other millets of significance to smallholder production and food security are also discussed. Sorghum and millets are known for being more tolerant of major environmental stresses including drought and poor soil quality than other major cereals. But water availability is still among the greatest constraints to increased grain production, and soil fertility also significantly limits yields, especially in cases where cultivation occurs on marginal lands and where crop residues are removed for alternative uses. Ultimately sorghum and millets’ relatively higher tolerance to abiotic stresses is expected to promote an increase in global cropping area for sorghum and millets as an adaptation to climate change. Sorghum and millet exhibit relatively few of the environmental impacts commonly associated with more intensively cultivated crops such as fertilizer runoff, pesticide contamination, or water depletion, since both of these crops are overwhelmingly grown by smallholder farmers with few, if any, chemical or irrigation inputs. Nevertheless, the tendency to grow sorghum and millet on marginal and heavily sloped lands does pose some environmental risks – including soil degradation and erosion – that can be mitigated through the adoption of best practices as described in the brief.
This review is one in a series that examines crop-environment interactions drawing on both the academic literature and the field expertise of crop scientists. Other briefs in this series include:
- Agriculture & the Environment: Overview (EPAR Technical Report #254)
- Agriculture & the Environment: Cassava Systems (EPAR Research Brief #228)
- Agriculture & the Environment: Maize Systems (EPAR Research Brief #215)
- Agriculture & the Environment: Rice Systems (EPAR Research Brief #208)
- Agriculture & the Environment: Wheat Systems (EPAR Research Brief #212)
- Agriculture & the Environment: Yam & Sweet Potato Systems (EPAR Research Brief #225)