Eating in Aridamerica: the desert food of the future
Last updated: 17 Aug, 2020
Heat waves, drought and disease are challenging food security in the southwestern USA and Mexico. Scientists are setting their sights on a novel model for desert farming.
As the National Weather Service warns that a heat wave spreading across the southwestern USA is of a "magnitude rare, dangerous and deadly," a team of scientists, led by the University of Arizona, has generated a new vision aimed at reducing climate disruptions to food security, human health and rural economies.
14 scientists from the southwestern USA and Mexico present a model for farming in arid landscapes that's designed to benefit land health, reduce disease risks and restore economic well-being to desert communities.
Intercropping of agave and columnar cacti near Las Canoas in Jalisco, Mexico. Photograph by Bill Hatcher.
The researchers propose restructuring desert food production from the ground up, by selecting wild food crops already adapted to extreme conditions. The desert food crops would be companion-planted or "intercropped" in designs that not only reduce heat stress in the plants, but among the farmworkers who care for them as well.
In ‘An Aridamerican model for agriculture in a hotter, water scarce world,’ the researchers call for a dramatic paradigm shift: to move desert food production away from water-consumptive, heat-intolerant annual crop plants.
Conventional agricultural approaches that focus on single species are becoming increasingly costly and unsustainable under rapidly changing climate and soil conditions, the researchers say. Instead, they suggest that farmers in arid landscapes select crops from wild, resilient native species already adapted to aridity.
"Desert plants have evolved a remarkable number of strategies to cope with heat, drought, unpredictable rainfall and poor soils," said Erin Riordan, a UArizona research associate and the principal scientist coordinating the binational research team at the University of Arizona's Desert Laboratory on Tumamoc Hill.
Such stressful agronomic conditions are predicted to dominate over half of the world’s land surface in the coming century, Riordan said.
To create their model, the interdisciplinary team of ecologists, anthropologists, ethnobotanists, restoration ecologists and public health professionals combined elements of high-tech energy and water harvesting solutions with the traditional ecological knowledge of desert foragers from the dry regions of North America, known as "Aridamerica."
"We see today's deserts not as wastelands but as laboratories for the future of agriculture," said Gary Paul Nabhan, lead co-author of the study and a research social scientist in the university's Southwest Center.
By combining ancient and cutting-edge strategies for dealing with rising temperatures, water scarcity and diseases exacerbated by heat stress, the researchers hope to make food production less daunting, dangerous and deadly for future desert dwellers.
The new model co-locates renewable energy production, rainwater harvesting and no-till food cropping of hardy perennials in the same spaces. The placement of several low-growing food crops under trees like mesquite and beneath photovoltaic panels allows for partial shade, soil moisture retention, soil microbe proliferation and carbon sequestration to benefit the plants.
By using heat- and drought-adapted food species such as agaves, cacti and nitrogen-fixing legume trees, these diverse systems can provide reliable yields of nutritious foods with minimal irrigation in the face of climate uncertainty.
“Cacti and agaves have functioned in many traditional cultures in Aridamerica as a form of insurance against environmental vagaries and annual crop failures,” said Exequiel Ezcurra, a Professor of Ecology at the University of California.
Read more about the research, including the benefits of consuming desert plants, here.
Read the paper: Nabhan, GP, Riordan, EC, Monti, L, et al. An Aridamerican model for agriculture in a hotter, water scarce world. Plants, People, Planet. 2020; 10.1002/ppp3.10129