Meet ARID: How desert ag science is growing resilient food systems

The desert is hot, dry, and full of soil challenges. But for scientists at ARID – the CALES Center for Agroecosystem Research in the Desert – that’s not a problem. It’s an opportunity.

It’s about growing crops that can thrive in a hotter, drier future, explained Duke Pauli, the center’s founding director and an associate professor in the School of Plant Sciences.

“Arizona has the climate of tomorrow, today,” he said. Arid lands cover roughly 41% of Earth’s land, support 30% of the global population, and produce more than 60% of the world’s food.

As populations grow and pressure on water and land increases, scientists are working to get the most from every drop of water and every acre of soil. By 2050, the world’s population is expected to hit 10 billion. At the same time, food production will need to increase by more than half just to keep up. ARID is working to support crops that can thrive while using fewer resources and position Arizona as a global leader in desert agricultural production.

“At the heart of ARID’s work is a deceptively simple question: Can we grow food in hotter temperatures using less water?” Pauli said. The answer is yes, but doing so requires a whole-ecosystem approach, combining plant genetics, microbial ecology, soil science, and digital technologies, he explained.

The Maricopa Agricultural Center (MAC), part of the Arizona Experiment Station, serves as ARID’s real-world proving ground, where desert conditions put crops, soil, and microbes to the test. In these fields, the research team studies plants like lettuce, sorghum, cotton, and Tepary beans under intense heat and limited water.

Plant genetics, phenotyping, and tons of data

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A centerpiece of this effort is the world’s largest outdoor phenotyping platform, a 30-ton robot that scans entire fields, monitoring thousands of plants at once to measure growth, leaf temperature, and photosynthetic efficiency or how well plants convert light to biomass.

By studying genetic variation within crops, the researchers are working to identify traits and specific genes that improve water use, heat tolerance, and nutrient composition. These traits may also influence how well plants interact with beneficial microbes, boosting stress resilience and increasing production, Pauli explained.

Phenotyping allows researchers to see how these elements actually play out in the field. They monitor plants for signs of stress, such as slowed growth, the ability to keep tissues green, or the capacity to stay cooler through sustained or increased transpiration. Together, genetics and phenotyping give a full picture of which plants are poised to succeed under desert conditions and can help inform future breeding decisions.

All of this work generates massive amounts of data, from field measurements to molecular signals. To make sense of it, ARID developed HAMRLNC (pronounced “hammer-link”), a computational tool that decodes the plant’s epitranscriptome or chemical “switches” on RNA that guide gene activity under stress.  

The data collected from field measurements, genetic analysis, and phenotyping are already helping the team explore the next frontier: digital plant twins or virtual models that can simulate growth, water use, and stress responses.  

With a $2 million grant from the National Science Foundation, Pauli and colleagues in Computer Science from Purdue University are developing this novel technology to further test and simulate how combinations of plant traits can lead to improved performance in an ever-changing environment, according to Pauli.  

“Using AI in combination with over half a petabyte of data, we can simulate future growing conditions to understand what the plant cultivars of the future will look like and how they will need to perform in order to be productive in a hotter, drier future,” he said. “ARID is really pushing the boundaries of what is possible in achieving food security in an increasingly challenging environment.”  

Microbes and soil: Partners in productivity

Plants don’t face the desert’s extremes alone. They rely on a “hidden workforce” of bacteria and fungi in their roots and leaves. These microbes influence everything from water use and heat tolerance to the nutritional quality of the food we eat, explained Betsy Arnold, ARID researcher and interim director of the School of Plant Sciences.

These microbes depend on another partner: the soil itself. Moisture, nutrients, and the mix of microbial life in the ground shape how well plants can survive. That’s something Debankur Sanyal, an ARID researcher and soil health Extension Specialist in the Department of Environmental Science, studies—focusing on how nutrients and chemicals move through arid soils. He tests sustainable and regenerative management techniques and develops strategies to improve crop productivity while supporting broader ecosystem functions.  

To study how plants work with soil and microbes, ARID scientists are building from ecological knowledge of arid-land plants, tapping into “wild wisdom” for agriculture. By studying wild-crop relatives and desert-adapted species, they can uncover microbial partnerships and plant traits that could help cultivated crops succeed in extreme conditions.

Alonso Favela, an ARID researcher and assistant professor in the School of Plant Sciences, studies plant–microbe interactions with a focus on rewilding those relationships in agricultural systems. His work examines how beneficial microbial partnerships found in wild plants can inform strategies to support crop performance.

“What’s powerful about ARID’s work in this area is that we’re identifying the principles that help one crop succeed—and discovering that those same principles can be applied to other crops in our dryland systems,” Arnold said. This mindset has expanded ARID’s focus to include both traditional and emerging crops suited to Arizona and the desert Southwest, she explained.

Cotton, Arizona’s primary fiber crop, and Tepary bean, a native desert legume, both thrive in our desert conditions in close collaboration with microbial partners. These crops exemplify what Arnold calls “symbiotic competence,” or the ability to rapidly and expertly form strong partnerships with desirable microbes to unlock nutrients and moisture in dry soil.  

Wild relatives of lettuce, including Lactuca serriola, provide a key window into these microbial interactions for leafy greens. By comparing wild and domesticated varieties, ARID researchers are learning how microbes contribute to flavor, nutrition, and durability, and which partnerships could improve crop performance under challenging conditions.

Sorghum, originally domesticated in the African savanna, is valued for its resilience and versatility as food, feed, and fuel. ARID researchers found that dry conditions reshape the root microbiome, and the plant’s own chemistry helps recruit beneficial microbes. Lower-performing varieties accumulate flavonoids, which can block helpful microbes, while higher-performing plants shift molecules like pipecolinic acid to encourage microbial partners that support growth.

Building on these insights, Pauli and ARID researcher Giovanni Melandri are exploring how sorghum handles short, intense “flash droughts,” putting the plant’s microbial and chemical strategies to the test in real-world conditions. As part of a $2.5 million Department of Energy-funded, multi-university project led by the Donald Danforth Plant Science Center, they are using high-resolution field phenotyping and biochemical analysis to identify traits that help the crop maintain growth and productivity under rapid drought stress.

Field tools and data in action

ARID’s research directly informs practical solutions for farmers, including testing and validating new technologies. One breakthrough involved real-time monitoring of cotton water status using microtensiometers, sensors installed directly on the plant’s stems. This was the first time these sensors were successfully used on small-stemmed row crops. They revealed that even well-watered plants don’t always fully recover overnight and that the plant’s internal response lags behind changes in the air, giving researchers a more precise view of how cotton handles stress.

For farmers, the technology offers clear benefits, according to Pauli. “Microtensiometers provide non-destructive, real-time monitoring of plant water status, enabling precision irrigation tailored to each plant’s actual needs,” he said.  

In the future, the sensors could be integrated into automated systems that trigger watering when a plant’s internal “thirst level” reaches a set threshold, conserving water while maintaining crop quality, Pauli explained.

Hands-on learning, team-driven discovery

ARID has supported graduate and undergraduate students across the university in hands-on research experiences, giving them the chance to learn alongside experienced researchers while contributing directly to innovations in arid-land agriculture. Four graduate students have completed their MS or PhD degrees, with four more currently in progress. In just two years, the center has also produced 17 academic papers – several with graduate students as lead or co-authors – and filed three invention disclosures.

“Engaging students in research brings them to the front lines of new innovations and solutions in arid-land agriculture,” says Arnold. "That’s one of many ways that the University of Arizona’s commitment to student engagement makes a difference now, and in the future."

“The real success of ARID is the team itself. The ability to bring driven researchers together to address grand challenges facing agriculture not only in Arizona but also the US and globally,” Pauli said. “By having a highly collaborative environment, ARID researchers can leverage the group’s skills to expand the scope and impact of their research.”

Environmental stress drives innovation in Arizona, sparking creative approaches to some of the toughest challenges in agriculture. By studying plants, soil, and microbes together, the ARID team takes a whole-ecosystem approach, aiming to position Arizona as a leader in arid-lands agriculture and supporting more resilient, sustainable, and productive global food systems.