Estimating the impact of climate change on cowpea production in Sudan Savanna using field cultivation data
Related Research Project
Africa upland farming system
Description
In the semi-arid region of West Africa known as the Sudan Savanna, cowpea — a drought-resistant legume crop — is widely cultivated. Despite its importance as a protein source in the region, the yield per unit area is extremely low, and there are concerns about the increasing impact of extreme weather events such as heavy rainfall and drought due to climate change in the future. Addressing climate change, including predicting future production variability and identifying its causes, is urgently needed.Yield prediction models can estimate crop yields by inputting meteorological conditions such as rainfall and temperature, as well as information about soil fertility and water characteristics. However, existing models targeting cowpea are specialized in predicting yields in optimal environments with minimal environmental stress, making it difficult for them to be applied to the harsh environments in Africa. To reveal the impact of climate change on cowpea production, this study aims to improve the accuracy of yield prediction models by utilizing field cultivation data in the Sudan Savanna accumulated in previous studies.
We created a yield prediction model using data from the cultivation of 20 cowpea varieties (n=1380) over four years with varying rainfall conditions in two representative soil types, Lixisols and Plinthosols, in the region. This allowed us to estimate yields in a wide range of environments, including dry and wet conditions (Fig. 1). Based on the latest global climate change predictions (Coupled Model Intercomparison Project Phase 6, CMIP6), it is forecasted that in West Africa, over the next 30 years, rainfall during the cowpea cultivation period (July to October) as well as the number of days with heavy rainfall exceeding 30 mm will increase (Fig. 2 top). The estimated yield model revealed that with increased rainfall and more days of heavy rainfall, cowpea yields in Lixisols will significantly decrease (Fig. 2 bottom). Furthermore, it is predicted that although cowpea yield reductions during drought periods will be mitigated compared to the present, drought-induced yield reductions will continue to be most severe in Plinthosols (Fig. 3).
Lixisols are relatively fertile and have high yields, making them significant areas for crop production. However, it is anticipated that excessive soil moisture stress will worsen due to increased rainfall, necessitating measures such as introducing tolerant varieties. In Plinthosols, drought-induced yield reductions are relatively greater than the reduction caused by excessive soil moisture, highlighting the need to control drought impact in the future.
Figure, table
- Research project
- Program name
- Term of research
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FY2016-2023
- Responsible researcher
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Iseki Kohtaro ( Biological Resources and Post-harvest Division )
Ikazaki Kenta ( Crop, Livestock and Environment Division )
KAKEN Researcher No.: 70582021Sakai Toru ( Social Sciences Division )
Iizumi Toshichika ( National Agriculture and Food Research Organization (NARO) )
Shiogama Hideo ( National Institute for Environmental Studies )
ORCID ID0000-0001-5476-2148KAKEN Researcher No.: 30391113Imada Yukiko ( University of Tokyo )
ORCID ID0000-0002-1270-8335KAKEN Researcher No.: 50582855Batieno Joseph ( Environmental Institute for Agricultural Research, Burkina Faso )
- ほか
- Publication, etc.
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Iizumi et al. (2023) Agricultural and Forest Meteorology 344: 109783.https://doi.org/10.1016/j.agrformet. 2023.109783
- Japanese PDF
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2023_B14_ja.pdf1.15 MB
- English PDF
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2023_B14_en.pdf1.35 MB
＊ Affiliation at the time of implementation of the study.