Resilient crop drying for small-scale farmers

In 2019, Adeboye Oluwagbemiga was walking through a community near his home in southwestern Nigeria when he saw a woman drying cocoa seeds in the sun on a tarp along the road. He looked up and saw rainclouds rolling in.

The farmer noticed the changing weather, too. She rushed to pack up her crop, and Oluwagbemiga and others tried to help. But when the storm hit, half of the cocoa seeds washed away.

“The look on her face. I can still see it,” Oluwagbemiga said. “It wasn’t anger, it was just this defeated exhaustion, like, ‘Here we go again.’”

The incident inspired Oluwagbemiga to understand the challenges of drying crops. He learned that farmers who use natural sunlight to dry their cocoa lose about 30 to 40 percent of their crop, and sun-drying cocoa can take six days.

As an agricultural and biological engineering student at Nigeria’s Federal University of Agriculture, Abeokuta, he wanted to find a solution that would help the farmer he saw – and millions of other small-scale farmers around the world – to more efficiently dry crops, including cocoa, coffee, chili, maize, and tomatoes.

“This project is something I’ve been waiting for,” he said. “I’m the type of person that has been putting effort into learning, and this is a time I can actually put what I’ve learned into action.”

Through the Global Sustainability Challenge platform online, he gathered a team of students from Nigeria, India, and Peru to design a hybrid drying system that utilizes the benefits of both solar power and biomass. When solar radiation is low, the biomass reactor provides heat to the system, allowing it to run 24/7.

With the system’s efficiency and controlled environment, a cocoa farmer could dry their crop in one day instead of six, he said. This speed, combined with the reduction in waste, would dramatically increase production rates.

“One of the issues we have in Nigeria is food security,” Oluwagbemiga said. “That’s why this project is important, because you need to focus on production for the economy to grow.”

The system also has environmental benefits. Larger farms use industrial dryers that run on expensive, emissions-heavy diesel. The biomass reactor runs on easily accessible cow dung, household waste, and agricultural waste.

Oluwagbemiga said his teammates understand each other and collaborate well. Their international perspectives have helped them consider the bigger picture: They envision their system being used by small-scale farmers who produce about a third of the world’s food but – like the woman Oluwagbemiga encountered – are vulnerable to factors beyond their control.

“That’s the world I want to see – where a farmer in Nigeria has the same basic security as a farmer in Brazil or Vietnam or anywhere else,” he said. “Where hard work and good farming practices translate to stability, regardless of what the weather does.”