Could the key to a sustainable food system already be growing in the world’s farms? Plant scientist Giles E.D. Oldroyd explores how a special quirk of soybean plants allows them to naturally partner with networks of fungi and bacteria to access essential nutrients in the air and soil — eliminating the need for synthetic fertilizers. He shows how harnessing these microscopic powerhouses could help scientists rewire crops to make their own fertilizer, reducing pollution, increasing yields and improving livelihoods for smallholder farmers.