AgBioResearch

Maize is the most produced cereal crop in the world, with more than 300 million Africans depending on it as a principal food source. Roughly a quarter of sub-Saharan Africa’s farmland is dedicated to maize production.

While farmers are frequently living a subsistence lifestyle, those who have enough food to sell at markets rely on the higher price they receive for maize to support themselves. But the cereal crop also poses a major problem. It zaps the soil of much-needed nutrients, and farmers can’t afford to have their land degraded at such a rapid pace. As the soil deteriorates, so too do maize yields.

Sieg Snapp, a professor in the Michigan State University Department of Plant, Soil and Microbial Sciences (PSM), is an expert on soil and cropping systems and the associate director of the Center for Global Change and Earth Observations at MSU.

The center uses science-based information to inform decision making on important environmental issues.

Snapp is also the founder of the Global Change Learning Lab to help facilitate collaboration between scientists and the general public.

She has led numerous participant-engaged research and outreach projects with farmers across Africa to better understand the challenges they face. While soils in Africa continue to degrade, she said farmers often don’t have access to the tools that can help them.

“There are many problems these farmers are dealing with, and solving them takes a holistic approach,” Snapp said. “One of the main difficulties is that policy favors maize so significantly that farmers are growing it season after season, and they can’t afford inorganic nitrogen to improve soil fertility.

“They must diversify their cropping systems, and that’s where legumes can help. But farmers want assurances that it won’t hurt the economics of their operations. We’re partnering with farmers to show the benefits of legumes while also working to influence policy change.”

Growing and harvesting two crops, such as maize and legumes, together is known as intercropping. Snapp said it is a vital innovation for farmers to improve soil and supplement income by producing a second crop. Maize is frequently paired with a legume, such as groundnut or pigeonpea, to add nitrogen back to the soil.

Taking this idea one step further, Snapp has advocated a method called doubled-up legumes — two legumes planted together that interact to fix nitrogen in the soil while also providing an additional protein source for the farmer. Snapp is hoping to show that while it may appear as a sacrifice to plant two legumes, the long-term benefits of added soil nutrients, less erosion and enhanced water availability are worth the investment.

Regis Chikowo, a soil scientist and assistant professor in PSM, is collaborating with Snapp on implementing these principles across Africa.

Chikowo leads the African RISING (Research in Sustainable Intensification for the Next Generation) project in Malawi. The initiative is assisting more than 1,000 smallholder farmers with recommended best practices such as intercropping, correct planting density, appropriate fertilizer application and new variety development.

“After working with some farming communities over several years, we have now begun to track a sub-set of the farmers to find out how they have expanded use of the technologies,” Chikowo said. “Moving good agronomy from only small portions of the farm to excellence at the whole-farm level is what will bring many farming families out of poverty.”