February 26, 2020 | By Kerry Clark

Field Notes - Soybean Innovation Lab is Mechanizing Agriculture Across Africa with Multi-Crop Thresher

Editor's Note: The Chicago Council is pleased to launch a new blog series, “Breaking Ground,” to explore how food systems innovation and agricultural research and development can empower farmers and feed the world.  A special subsection of our series, “Field Notes,” features voices from Feed the Future Innovation Labs and CGIAR centers. We will publish weekly posts, culminating in the Global Food Security Symposium on March 26. 

Many smallholder farmers in the tropics do not have access to durable and affordable harvest equipment such as crop threshers. When the Soybean Innovation Lab (SIL) began their work in Ghana in 2016, they saw a pressing need for mechanized crop threshers to relieve the huge burden of stick threshing that is often done by women and young people.

Soybean threshing by stick beating is a long and exhausting process in most production areas in Africa. These boys in a village outside of Yendi reported that it takes them over a week to thresh and winnow an acre of soybeans. Photo: Dr. Kerry Clark

SIL held a contest between three U.S. and three Ghanaian universities for students to develop a thresher for local fabrication by village blacksmiths at a manageable price. Jeffrey Appiagyei, a 2017 graduate of Kwame Nkrumah University of Science and Technology in Kumasi, Ghana, was one of the winners of the contest and turned that success into a career and a mission. “I want to change things at the national level” said Jeffrey. “I want young people to see the potential of the huge African market and the vast space available for locally produced, high quality agricultural equipment. To accomplish sweeping change in the technological ability of a community or country to support its entire agricultural value chain, local innovation and machinery fabrication is essential.”

Appiagyei works with the Soybean Innovation Lab to create and provide training programs for young engineers, equipment fabricators and vocational schools to enable the local manufacture of agricultural equipment such as the SIL Multi-Crop Thresher. Together with Appiagyei’s company SAYeTECH, the Soybean Innovation Lab is creating a local, skilled workforce for the fabrication of low-cost, locally-produced, multi-crop threshers to address the challenges of availability and affordability that prevent many smallholder farmers from scaling up their agricultural production. Locally-made also means locally-repaired. Local fabricators listen to customer needs and can customize equipment for individual or groups of end-users, and can provide maintenance and repair services locally.

SIL provides customized training workshops in multi-crop thresher fabrication across Sub-Saharan Africa. Workshops include training on business development, maintaining manufacturing quality and training and educating end-users of machines on operation and maintenance. Photo credit: Dr. Kerry Clark

Manual threshing, disproportionally carried out by women, is labor intensive and time consuming. SIL’s multi-crop thresher is 80 percent faster, requires only 2 operators, and reduces postharvest losses by 35 percent. It is designed to be quickly and easily switched between crops by changing out a perforated metal sieve concave. The hole sizes of the sieve depend on local crops and their average seed sizes, but in most locales only two sieves are needed: one for maize, beans, and other large-seeded crops; and another for soybean, rice, and grains of smaller size. The thresher sits on a metal frame with four wheels and can be powered with a diesel engine or a tractor power takeoff.

Starting with just 12 fabricators from Ghana in 2016, SIL has now trained 142 fabricators across 7 countries to build, service and maintain threshers that can handle cowpea, maize, soybean, millet, sorghum and rice. For each training, the in-country partner recruits the fabricators, finds the training facility, finances the materials for production, and supports the trainees with food during the training hours. The Soybean Innovation Lab can train 10–20 people at a time and build 1–3 threshers during the week-long training.

SIL trainer Hakeem Abdul-Karim (right) reviews necessary math skills with trainees in Rwanda. Photo credit: Dr. Kerry Clark

For local fabrication to then reach smallholder farmers, organizations must make strong efforts to connect the manufacturers with people who can buy the threshers. Assistance from Catholic Relief Services and SIL with promotional events, such as thresher demonstrations at field days or farmer fairs, has helped recruit customers for fabricators in Ghana, where over 100 multi-crop threshers are now in use.

SIL has trained 142 fabricators across 7 countries in Africa since 2016, with the intent to add Kenya, Nigeria, and Zimbabwe to that list in 2020.

If you’d like to learn more about how to become an in-country partner to train young people to manufacture, operate and repair the SIL multi-crop thresher, or are interested in getting a thresher yourself, please contact Dr. Kerry Clark, Mechanization Lead, Soybean Innovation Lab, and Director of CAFNR International Programs and Assistant Research Professor, University of Missouri.


Read our previous posts in the Breaking Ground series:

Guest Commentary - The Critical Role of Women in Transforming the Food System

Guest Commentary - Adopting Conserving Agricultural Practices: A Farmer's Perspective

Guest Commentary - Investing in Innovation: Food, Agriculture and Forestry in Southeast Asia

Field Notes - To Meat or Not to Meat: Balancing Global Viewpoints in Battles over Food

Field Notes - Boosting Nutrition and Sustainability through Superfoods in Local Food Systems

Guest Commentary - Envisioning the Future of Food in Times of Change

Field Notes: Biocontrol of the Fall Armyworm - Long-term Resilience for Small-scalle Farmers


The Global Food and Agriculture Program aims to inform the development of US policy on global agricultural development and food security by raising awareness and providing resources, information, and policy analysis to the US Administration, Congress, and interested experts and organizations.

The Global Food and Agriculture Program is housed within the Chicago Council on Global Affairs, an independent, nonpartisan organization that provides insight – and influences the public discourse – on critical global issues. The Council on Global Affairs convenes leading global voices and conducts independent research to bring clarity and offer solutions to challenges and opportunities across the globe. The Council is committed to engaging the public and raising global awareness of issues that transcend borders and transform how people, business, and governments engage the world.

Support for the Global Food and Agriculture Program is generously provided by the Bill & Melinda Gates Foundation.


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| By Roger Thurow

Our New Gordian Knot

Fifty years ago Dr. Norman Borlaug recieved the Nobel Peace Prize for cutting the "Goridan knot" of population and food production. Now the planet faces another seemingly intractable problem: how to nourish the planet while preserving the planet.