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Scientists Work In Arizona To Reshape Desert Food Production
The experimental garden at Biosphere 2 about 35 miles north of Tucson is part of a wider effort to radically reshape desert food production to meet the growing challenges posed by climate change
Methods To Increase Yield, Lower
Water Use Draw On
Practices of Indigenous Cultures
Caleb Ortega, an environmental studies undergraduate student, harvests basil from an experimental garden outside Biosphere 2. Record heat has given the research new urgency.
Josh Galemore/Arizona Daily Star
TUCSON, Ariz. (AP) – In the cool shade of solar panels, a lush plot of herbs and vegetables hints at one possible future for farming in the desert.
At the moment, that future includes more basil than researchers know what to do with.
“We’ve been pulling out pounds of it every week,” said University of Arizona biogeographer Greg Barron-Gafford. “All of us are getting a little sick of pesto and pizza and mozzarella at this point.”
The experimental garden at Biosphere 2 about 35 miles north of Tucson is part of a wider effort to radically reshape desert food production to meet the growing challenges posed by climate change.
The 14 researchers from the Southwest and Mexico believe their model can produce a sustainable, local source of food that will improve the health and well-being of consumers and farmworkers alike.
The idea involves a mix of desert-adapted food species grown cooperatively in ways that increase yield while reducing water use.
Picture a variety of agave and fruit-bearing cactus interspersed with rows of mesquite and other legume trees, all with wild herbs, greens, beans, and native chiltepin peppers growing in the shade beneath them. Other potential crops include squashes, mints, and jicama.
In some cases, those plants would be grown beneath a photovoltaic “canopy,” as the solar panels generate cheap, renewable electricity to pump irrigation water and power farm equipment.
Pilot projects to test the model are now underway in the U.S. and Mexico, including at Biosphere 2 and in campus gardens at three public schools across southern Arizona.
“I like to think of it as using the desert and the sun here as our laboratory for the future,” said Erin Riordan, a UA research associate and one of the lead authors on a scientific paper about the project.
The team focused on desert plants that are as nutritious as they are drought-tolerant, with special emphasis on crops that can reduce or even prevent diabetes and other chronic diseases often exacerbated by heat stress.
Meanwhile, the shady design of the growing areas would benefit both the plants and the workers tending to them, curbing the frequency of injuries or illnesses associated with farm labor in extreme environments.
The sweeping proposal, published recently in the journal Plants, People, Planet, is rooted in practices perfected over millennia by Indigenous desert cultures.
“People have been growing food in the shade for 4,000 years in this region,” Barron-Gafford said.
“It’s not something that’s new to anyone,” said Gary Paul Nabhan, the study’s other lead author and a research social scientist in the university’s Southwest Center. “We’re drawing on that expertise and combining it with modern techniques and technology.”
Solar panels, healthy crops
The importance of food security has been highlighted in recent months by record-setting heat, sputtering monsoon conditions, and supply disruptions caused by the pandemic.
“We are already hitting the temperature limits of conventional crops,” said Nabhan, a MacArthur award-winning agroecologist and the endowed chairman in food and water security at UA.
Greg Barron-Gafford, Caleb Ortega, and Alyssa Salazar work in a garden that is part of an experiment on growing techniques for hotter, drier desert conditions. Josh Galemore/Arizona Daily Star
Among the Southwestern farm staples most threatened by global warming, he lists corn, dry beans, melons, chiles, and most vegetables.
“Yes, we can still grow chiles in our backyards,” he said, but growing them in a large-scale agricultural setting will become increasingly difficult as temperatures rise, droughts deepen and water resources shrink.
Nabhan said a market already exists for some of the new crops considered in the study. “They’re already in our grocery stores, but we’re importing them from 1,000 miles away,” he said.
Back at his outdoor laboratory at Biosphere 2, Barron-Gafford said pairing agriculture directly with solar generation could “open the door to food production in marginal lands” by providing both a shady place to grow plants and the electricity needed to pump water to them.
For the right crops, the shade beneath the solar panels can produce healthier, more productive plants with as little as half the water, all while extending the length of the growing season.
In turn, the plants provide a benefit to the solar array, cooling the air around it by as much as 12 degrees and improving the efficiency of the panels.
Barron-Gafford said the experiment in so-called “agrivoltaics” began nine years ago with a few plants tucked underneath a single, small solar panel slanting up from the ground.
“We started with salsa plants because we’re here,” he said with a smile.
Some crops grow, others don’t
The test garden now covers an area about the size of a half-court in basketball, shaded by a solar array mounted 10 feet off the ground.
Along with all the basil, the current crop includes heirloom cherry tomatoes, Anasazi red beans and a special type of bell pepper Barron-Gafford said was brought in from Mexico by the chefs at Penca restaurant in Tucson.
In a nearby control garden, equal-sized plots of the same plants bake in the direct sun. The basil there doesn’t even look like the same species. Its leaves are skinnier and more pointed, and the plants are already going to seed. One patch has shrunk and dried out in the heat after its water ration was cut in half to match a similar plot still going strong in the shade of the solar array.
“Those plants died for science,” said Barron-Gafford, an associate professor with the UA’s School of Geography, Development, and Environment.
He and his research assistants planned to plant a fall crop – both in the shade and out – of cilantro, fava beans, white onions, and native mouse melons, which taste like cucumbers but look like miniature watermelons.
Agrivoltaic farming doesn’t work for everything. Broccoli, for example, tends to grow large, impressive leaves in the shade, but it never produces florets.
The jury is still out on the Anasazi beans. Barron-Gafford said the ones planted in the direct sun of the control garden have already produced their crop of seed pods, while the ones shaded by the solar array are taking their sweet time.
Whether that will lead to a fuller, more flavorful bean or a pile of tiny, underdeveloped pods remains to be seen.
Questions about scaling up
There’s one thing the research team already knows: Transforming an entire agricultural sector won’t be easy.
“It is a big shift,” said Riordan, the principal scientist coordinating the binational research team based at the UA’s Desert Laboratory on Tumamoc Hill. “There’s a huge scaling piece that is going to have to be addressed.”
One key part will be convincing consumers to expand their palates to include wild, locally grown foods they might not have considered before.
Luckily, Riordan said, Tucson already has something of a head start there, thanks to its diverse population, rich cultural history, and its designation six years ago as the first UNESCO City of Gastronomy in the U.S.
The community is already home to about 40 startup businesses that produce more than 120 new desert food and beverage products.
Ultimately, researchers argue, desert agriculture will be transformed by climate change whether we want it to be or not. Through careful planning and adaptation, we can make that transition profitable instead of painful.
“It might be hard right now to envision edible desert landscapes, but it might not seem so far-fetched in a few years,” Riordan said. “I think we’re going to have a lot of motivation to come up with big solutions fast.”
Namibia: Farm Shalom Thrives In The Desert
The stretch of land east of Swakopmund is vast, extremely arid and it appears lifeless but in the Namib Desert where one would not have expected an agronomic venture is where Farm Shalom thrives, growing a variety of veggies such as peppers, spinach and different types of flowers
2019-07-01
WINDHOEK - The stretch of land east of Swakopmund is vast, extremely arid and it appears lifeless but in the Namib Desert where one would not have expected an agronomic venture is where Farm Shalom thrives, growing a variety of veggies such as peppers, spinach and different types of flowers.
Most of the desert wildlife consists of arthropods and other small animals that live on very little water although this desert that stretches all the way to northern Namibia is inhabited by larger animals in the northern part of Namibia where its vast expanse stretches all the way to Angola.
Namibia is the driest sub-Saharan country and is the most severely affected by climate change, with rising temperatures, rainfall variability and increased droughts and severe flooding but AvaGro grows flowers and vegetables on a commercial basis in the Namib Desert.
The head of agronomist at AvaGro Ranjit Patil told New Era upon enquiry that the eight-hectare Shalom farm located 10 kilometres outside Swakopmund on the banks of the Swakop River has 27 greenhouses “where we grow cucumbers, peppers and tomatoes.”
On this piece of land turned into farmland in the oldest desert in the world, Patil and his team the majority of whom are Namibians employed as salaried workers, also grow roses and gerberas, beetroot, eggplant, herbs and spinach ‘’using open field cultivation.”
“We use high tech agriculture as climate change threatens traditional farming methods. These high-tech agriculture methods are tried and tested in India and we are replicating success here in Namibia. This involves setting up greenhouses to create a controlled environment and use of hydroponic methods like the growing media, cocopeat. Cocopeat has high water holding capacity, is heat stabilising and has high levels of porosity, which makes it ideal for farming in challenging environmental conditions,” narrated the head agronomist who holds a Master’s degree in agriculture.
“We also use soil optimisation methods for the crops we cultivate in the open, by adding manure and grass to the soil,” Patil further elaborated when queried how they have managed to utilise the desert into productive land.
“Namibia is the driest sub-Saharan country and is most severely affected by climate change, with rising temperatures, rainfall variability and increased droughts and floods. The desert soil causes limited fertility and irrigation, requires highly capital-intensive methods of production and reduces crop production,” he said in response to a question from this newspaper.
“Climate-adapted cultivation methods are needed to secure sufficient food availability in the country. High-tech agriculture with media cultivation (cocopeat) is an effective solution to overcome challenges of soil through greenhouse efficiencies. Since in India we have similar climatic conditions so it’s a win -win situation to share our expert skills with fellow Namibians,” says an upbeat Patil.
The Indian company bought the plot in 2015 and set up its first greenhouses in 2016 and 97 percent of its staff compliment of 30 employees are Namibian creating much-needed jobs for locals.
On the challenges faced he says, “climate is a key challenge that we address with precision agriculture. We address the challenge of skill through customised training programmes,” and the company uses a hydroponic system, cocopeat, to optimise growth to offset water scarcity.
Productive-wise “We harvest six tonnes of tomatoes, three tonnes of peppers and 10,000 pieces of cucumber per greenhouse (350 square metre) per season (comprising six months). We have two seasons per year and harvest on a regular basis,” says the head of agronomist at Shalom Farm.
“We work with smallholder farmers, agri-preneurs and established medium and large-scale cultivators to develop bespoke production plans to advance food sovereignty. In terms of market access, we have off-take agreements with local wholesalers and retailers,” he said on market access.
“At Shalom, we’re contributing to the shift from traditional farming to precision agriculture. This involves applying efficient water-use systems, augmenting the soil and using hydroponic mediums to grow crops. At Shalom, we are showing what is possible with the right mix of determination, technology and skills. If we can foster sustainable agriculture in the desert, where constraints – water, soil and climate – are amplified; we can do it anywhere,” he said.