But what of the halophytes?*
From Knowable Magazine, November 21:
Miles away from the ocean, projects are afoot to clean up salty groundwater and use it to grow crops. Some say it’s a costly pipe dream, others say it’s part of the future.
Ralph Loya was pretty sure he was going to lose the corn. His farm had been scorched by El Paso’s hottest-ever June and second-hottest August; the West Texas county saw 53 days soar over 100 degrees Fahrenheit in the summer of 2024. The region was also experiencing an ongoing drought, which meant that crops on Loya’s eight-plus acres of melons, okra, cucumbers and other produce had to be watered more often than normal.
Loya had been irrigating his corn with somewhat salty, or brackish, water pumped from his well, as much as the salt-sensitive crop could tolerate. It wasn’t enough, and the municipal water was expensive; he was using it in moderation and the corn ears were desiccating where they stood.
Ensuring the survival of agriculture under an increasingly erratic climate is approaching a crisis in the sere and sweltering Western and Southwestern United States, an area that supplies much of our beef and dairy, alfalfa, tree nuts and produce. Contending with too little water to support their plants and animals, farmers have tilled under crops, pulled out trees, fallowed fields and sold off herds. They’ve also used drip irrigation to inject smaller doses of water closer to a plant’s roots, and installed sensors in soil that tell more precisely when and how much to water.
In the last five years, researchers have begun to puzzle out how brackish water, pulled from underground aquifers, might be de-salted cheaply enough to offer farmers another water resilience tool. Loya’s property, which draws its slightly salty water from the Hueco Bolson aquifer, is about to become a pilot site to test how efficiently desalinated groundwater can be used to grow crops in otherwise water-scarce places.
Desalination renders salty water less so. It’s usually applied to water sucked from the ocean, generally in arid lands with few options; some Gulf, African and island countries rely heavily or entirely on desalinated seawater. Inland desalination happens away from coasts, with aquifer waters that are brackish — containing between 1,000 and 10,000 milligrams of salt per liter, versus around 35,000 milligrams per liter for seawater. Texas has more than three dozen centralized brackish groundwater desalination plants, California more than 20.
Such technology has long been considered too costly for farming. Some experts still think it’s a pipe dream. “We see it as a nice solution that’s appropriate in some contexts, but for agriculture it’s hard to justify, frankly,” says Brad Franklin, an agricultural and environmental economist at the Public Policy Institute of California. Desalting an acre-foot (almost 326,000 gallons) of brackish groundwater for crops now costs about $800, while farmers can pay a lot less — as little as $3 an acre-foot for some senior rights holders in some places — for fresh municipal water. As a result, desalination has largely been reserved to make liquid that’s fit for people to drink. In some instances, too, inland desalination can be environmentally risky, endangering nearby plants and animals and reducing stream flows.
But the US Bureau of Reclamation, along with a research operation called the National Alliance for Water Innovation (NAWI) that’s been granted $185 million from the Department of Energy, have recently invested in projects that could turn that paradigm on its head. Recognizing the urgent need for fresh water for farms — which in the US are mostly inland — combined with the ample if salty water beneath our feet, these entities have funded projects that could help advance small, decentralized desalination systems that can be placed right on farms where they’re needed. Loya’s is one of them.
US farms consume over 83 million acre-feet (more than 27 trillion gallons) of irrigation water every year — the second most water-intensive industry in the country, after thermoelectric power. Not all aquifers are brackish, but most that are exist in the country’s West, and they’re usually more saline the deeper you dig. With fresh water everywhere in the world becoming saltier due to human activity, “we have to solve inland desal for ag … in order to grow as much food as we need,” says Susan Amrose, a research scientist at MIT who studies inland desalination in the Middle East and North Africa....
Back in September 2014 we were looking at one possible use for these little guys, now there may be others:
For now just a personal bookmark.
If the idea of greening deserts with canals of seawater pans out we'll be back with more.
From Aeon Magazine:
Ever since ancient times, the sowing of salt has been synonymous with severe and deadly retribution. The Roman general Scipio Africanus the Younger was said to have ended the Third Punic War in 146BC by razing Carthage, enslaving its population and spreading salt on its fields. In the biblical book of Judges (9:45), the brutal and unprincipled King Abimelech laid siege to the Canaanite city of Shechem. ‘He took the city,’ the biblical story says, ‘and slew the people that was therein, and beat down the city, and sowed it with salt.’
Salt kills most plants. In fact, it attacks them in much the same way that carbon monoxide kills humans. In cases of carbon monoxide poisoning, CO molecules exhaust the carrying capacity of your red blood cells, depriving your body of the oxygen it needs. Likewise, most terrestrial plants soak up the sodium ions and sodium chloride from salt much faster than they can absorb essential nutrients such as potassium, calcium and magnesium. Without those nutrients, they perish. Spread salt on the fields of your enemies and their crops will fail.Additionally:
More than 97 per cent of the water on Earth is saline. Wouldn’t it be cruel if nature had locked up the vast bulk of the planet’s vital fluids in a form that no plant could drink? Well, as it happens nature is not quite that cruel. Of the 400,000 flowering plant species around the world, 2,600 do drink seawater. They are halophytes, meaning ‘salt-plant’, and they might just be the answer to a question surprisingly few governments have yet asked: namely, how can we put our planet’s practically infinite volumes of saltwater to good use?
It might not be immediately obvious why such a question is worth our time. But consider: between sea-level rise and the increase in droughts and floods, the acreage available for conventional, freshwater agriculture is shrinking rapidly. Freshwater aquifers are becoming increasingly salty: among them, the Ogallala Aquifer, which covers a quarter of the irrigated land in the US. And so one of the world’s most important breadbaskets is under threat. Elsewhere, one-sixth of the world’s population relies on Eurasian rivers that trace back to Himalayan glaciers, which are themselves disappearing because of climate change....MORE
Royal Kew: "Salt Tolerance (eHALOPH)"
DesertCorp
US Salinity Laboratory: Research Databases
USDA: Salt-Tolerant Plants
Boston University BU Today: Lessons from Venice
