Agriculture

Global warming will reduce maize yields in Africa in the near future

Maize is a staple crop in Africa and many farmers are consumers are heavily dependent on it

 
By Srilakshmi Nambiar
Last Updated: Wednesday 22 June 2016

Crop duration will become significantly shorter by as early as 2018

Climate change is likely to affect the cultivation of maize—a crop crucial to Africa’s trade and diet—a new study by reaseachers at University of Leeds, has found. The study that was published in journal Nature Climate Change, focuses on how maize cultivation will be affected by warmer climates.

How will climate change affect maize cultivation?

The process of breeding, delivery and adoption (BDA) of new maize varieties can take up to 30 years. By looking at a range of data on farming, regulatory policy, markets and technologies, the researchers developed average, best and worst case scenarios for current crop breeding systems, trying to assess the implications of warming during the BDA process.

The study showed that crop duration will become significantly shorter by as early as 2018 in some locations and by 2031 in the majority of maize-growing regions in Africa. Climate change would have a negative impact on crop yields as heat and drought stress can shorten production time. Maize varieties currently being developed may struggle to adapt as current breeding and commercialisation cycles to improve maize can take several decades to complete.

Lead author of the study, Andy Challinor, of the Priestley International Centre for Climate at the University of Leeds said, "In Africa, gradually rising temperatures and more droughts and heat waves caused by climate change will have an impact on maize. We looked in particular at the effect of temperature on crop durations, which is the length of time between planting and harvesting. Higher temperatures mean shorter durations and hence less time to accumulate biomass and yield."

Reduced crop duration means that growing seasons may not be long enough to allow maize plants to fully mature. The research also points out that the current pipeline for breeding climate-ready maize varieties is not keeping pace with the rate of climate change.

Investment in agro-tech is the way forward

The research team, comprising of experts in agriculture, climate and social science, looked at the options for ensuring that crops can be developed and delivered to the field more quickly. These range from improved biochemical screening techniques to more socially-centered measures, such as improving government policies on breeding trials and farmers' access to markets.

Andy Jarvis, of International Centre for Tropical Agriculture (CIAT) said, "Investment in agricultural research to develop and disseminate new seed technologies is one of the best investments we can make for climate adaptation. Climate funds could be used to help the world's farmers stay several steps ahead of climate change, with major benefits for global food security."

An intensive breeding effort through the Drought Tolerant Maize for Africa (DTMA) project developed a large phenotyping network and breeding pipeline to produce new maize varieties with heat and drought tolerance. In 2015, a new project was started to expand DTMA so that more smallholder farmers in Africa would have access to affordable and improved maize varieties.

The researchers have also proposed an alternative plan: use global climate models to determine future temperatures, then heat greenhouses to those temperatures and develop new crop varieties there. However, the challenge here is identifying suitable heat stress sites where trials could be undertaken.

Despite the considerable efforts being made to adapt maize farming to changing climates, co-author of the study, Biswanath Das warned that they must be sustained and encouraged on a larger scale in order for breeding programmes to produce climate-ready maize varieties for the future.

This study was supported by the CGIAR Research Programme on Climate Change (CCAFS) and the CGIAR Research Program on Maize (MAIZE CRP).

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