Tackling the challenges of sustainable cocoa farming

Changing farming methods to better withstand shocks will be crucial to the cocoa industry, and will ensure that chocolate fans around the world can sustainably indulge their sweet tooth.

Throughout the 2010s there were fears of a looming chocolate shortage. Though demand has been steadily increasing for 50 years, production decreased by around five per cent from the early part of the decade.

The $80 billion chocolate industry depends on output from farmers who, in many cases, are earning less than they did in the 1980s. In Ghana and Côte d'Ivoire, which supply two-thirds of the cocoa used by the chocolate industry, degraded soils and pathogens have negative effects on supply while future production is threatened by climate change.

In order to help sustain the livelihoods of cocoa farmers and to discover how the entire cocoa supply chain can become both more resilient and sustainable, researchers from ETH Zurich traveled to Ghana and Côte d'Ivoire to learn from the farmers and co-create solutions.

Research by Jonas Jörin, from ETH Zurich, and colleagues from ETH and Kwame Nkrumah University of Science and Technology (KNUST), found that more frequent and intense shocks from climate change and market fluctuations are a risk not only to farmers but also to other stakeholders across the supply chain, including processors, licensed buying companies and suppliers.

They found that stakeholders in the value chain relied on financial resources to absorb and recover from a shock, such as a drought. Farmers felt that they could do more to improve farm management practices, but many of the measures they proposed would require external help from the private sector, academia and NGOs.

"It is crucial to equip stakeholders with opportunities to diversify their activities," the report concluded. "For example, farmers have to adjust farm management practices to better cope with drought risks and processors may create more added value by moving beyond the production of semi-finished products and instead produce chocolate products that directly reach consumers."

In another project, Wilma Blaser and colleagues from ETH and CSIR in Ghana looked at ways to make cocoa yields more stable with sustainable farming methods. This includes, for example, a return to growing cocoa in the shade of other trees. Traditionally, this was how cocoa was grown but it was gradually replaced by higher-yield methods.

But the benefits of shade trees go beyond protecting the cocoa from too much sun. They also provide a habitat for animals and other plants and keep harmful organisms in check. What's more, they absorb carbon from the atmosphere, which provides climate mitigation potential, and may play a role in maintaining soil fertility.

The downside is that they increase competition for light and nutrients and therefore can reduce the yield from cocoa plants. Researchers compared shaded and unshaded cocoa crops and found that the optimal amount of shade tree cover is 30 percent. This keeps pests and diseases in check and maintains soil moisture. The cooling effect on temperature, the number of animal and plant species in the field, and the carbon sequestration all increase with an increase in the amount of shade. More than 30 percent, however, reduces the cocoa yield.

The researchers are now examining whether certain types of tree are more beneficial than others. Their findings, and those of other researchers, might help ensure that our chocolate supplies don't run out just yet.

For more on the work of the Sustainable Agroecosystems Group of Professor Johan Six at ETH Zurich, visit https://sae.ethz.ch/