Climate change impacts and adaptation strategies for crops in West Africa: a systematic review

Abstract

Agriculture in West Africa faces the challenge of meeting the rising demand for food as national incomes and populations increase while production becomes more uncertain due to climate change. Crop production models can provide helpful information on agricultural yields under a range of climate change scenarios and on the impact of adaptation strategies. Here, we report a systematic review of the impact of climate change on the yield of major staple crops in West Africa. Unlike earlier reviews we pay particular attention to the potential of common agricultural adaptation strategies (such as optimised planting dates, use of fertilisers and climate-resilient crop varieties) to mitigate the effects of climate change on crop yields. We systematically searched two databases for literature published between 2005 and 2020 and identified 35 relevant studies. We analysed yield changes of major staple crops (maize, sorghum, rice, millet, yam, cassava and groundnuts) caused by different climate change and field management scenarios. Yields declined by a median of 6% (-8% to +2% depending on the crop) due to climate change in all scenarios analysed. We show that the common adaptation strategies could increase crop yields affected by climate change by 13% (-4% to +19% depending on the strategy) as compared to business-as-usual field management practices, and that optimised planting dates and cultivars with longer crop cycle duration could in fact offset the negative effects of climate change on crop yields. Increased fertiliser use has not mitigated the impact of climate change on crops but could substantially increase yields now and in the future. Our results suggest that a combination of increased fertiliser use and adopting cropping practices that take advantage of favourable climate conditions have great potential to protect and enhance future crop production in West Africa.

Attributing synergies and trade-offs in water resources planning and management in the Volta River basin under climate change

“…According to Dossou-Yovo et al [28], farmers' yields in Sub-Saharan Africa are low, 2.2 t ha −1 compared to the world average of 4.6 t ha −1 . Poor soil fertility and low soil clay contents are major constraints for crop productivity [29], but nitrogen and phosphorus fertilizer applications increase yields considerably [28,30,31], particularly if combined with improved seeds [32] and irrigation [12].…”

“…sealed canals), irrigation practice (e.g. drip irrigation), and optimized timing of crop schedules [30], rather than by deficit irrigation.…”

Addressing future food demand in The Gambia: can increased crop productivity and climate change adaptation close the supply–demand gap?

“…These practices include shifting planting dates, changing crop varieties (e.g., drought-resistant crops), crop rotations, altering soil management and fertilisation, and improving water management, among others (Segnon et al, 2021 ). The estimated impact of CCA practices on crop yields was based on a systematic review of climate change and adaptation strategies on major crops in West Africa (Carr et al, 2022 ), which showed that crop yields can increase by 13% on average by adopting techniques such as optimised planting dates, climate-resistant varieties, and increased fertiliser use under changing climate conditions. Intensified nutrient and water management (Boost) scenarios: We estimated the increase in crop yield resulting from improved access to irrigation and fertiliser based on simulated yield potentials achievable with reduced water and nutrient stress.…”

Integrated Spherical Decision-Making Model for Managing Climate Change Risks in Africa

“…Africa is highly vulnerable to climate change [1], which is expected to disrupt water, food, and health systems. These changes could worsen existing issues like poverty and insecurity, impacting economic development [2].…”