You’re now mainly focused on encouraging farmers throughout Africa to plant perennial crops that will feed people while maintaining soil health. Is soil there in worse shape than in North America?
JG: African soils were in general less fertile and less well-suited for agricultural production than American soils from the beginning. Farmers in Africa are often faced by the big challenge of working with inherently old, highly weathered soil. By this point, their soils have also been heavily eroded. And so that’s where we need improvements most and most immediately.
Where have you seen perennial crops be successful?
JG: I recently visited a system in Malawi [in southeastern Africa] in which pigeon peas, which can be grown as either an annual or perennial crop, are actually grown together with soybeans, which are annuals. Once the soybeans and pigeon peas are harvested, the pigeon peas are allowed to regrow. When they’re regrowing, maize is planted into the pigeon peas. In the past, farmers would have grown just maize alone, or they might have rotated the maize with soybeans, but with this system they’re now getting two harvests of legumes in one season — the pigeon peas and the soybeans — and then in the second season they’re getting a harvest of maize and pigeon peas. So they’re really increasing the amount of protein they’re growing on their farm, and that’s valuable both in terms of the nutrition in the household, as well as valuable on the market. From my point of view as more of a soil scientist, it really adds a lot of benefits to soil, too.
What are some of the obstacles to getting more African farmers to grow perennials?
JG: Pigeon peas are already quite widely used, but mostly as annual crops. Their perennial benefits could be much more widely taken advantage of. The obstacle to the other crops being adopted is that there just hasn’t been enough plant breeding done to sufficiently improve perennial wheat and sorghum and test them in farmers’ fields.
Do you think that perennial crops could be valuable and useful in the developed world, too?
JG: I think ultimately they could be more productive than our annual grain crops because they are able to capture more sunlight, water and nutrients. But the urgency in developed countries isn’t there. The political will, the support by the farm community itself, probably isn’t quite as great.
[This article originally appeared in print as "Feed the World."]