In the upcoming film Interstellar, Earth’s soil has become so degraded that only corn will grow, driving humans to travel through a wormhole in search of a planet with land fertile enough for other crops. In the real world things aren’t quite so dire, but degraded soil is a big problem—and one that could be getting worse. According to a new estimate, one factor, the buildup of salt in soil, causes some $27.3 billion annually in lost crop production.
“This trend is expected to continue unless concrete measures are planned and implemented to reverse such land degradation,” says lead author Manzoor Qadir, assistant director of water and human development at the United Nations University Institute for Water, Environment and Health. Qadir and his colleagues published their findings October 28 in Natural Resources Forum.