High resolution x-ray analysis reveals the inner life of leaves while advancing engineering efforts to reduce crop sweat

Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

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 A machine-learning labeled cross-section of a sorghum leaf generated with microCT imaging.

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Credit: James Fischer

In the midwestern summer, humans and plants have to breathe through the heat and humidity. Researchers hope that a retooled crop plant—one with an improved ventilation system within its leaves—could thrive while avoiding drought stress by reducing “crop sweat”. Thanks to a next generation imaging technology powered by Argonne National Laboratory’s particle collider beamline, a team of scientists now has precise schematics of the leaf’s interior and can refine approaches to breeding hardier crop plants. 

The research, published in Plant Physiology, was led by postdoctoral researcher James Fischer in the laboratory of Professor of Plant Biology and Crop Sciences Andrew Leakey at the University of Illinois Urbana-Champaign. Their work represents the first detailed look at how the pores on the leaf surfaces of sorghum, a highly productive and resilient grass crop, connect to the air pathways, photosynthetic centers, and veins beneath. 

“There are connections between each component of the leaf . . . it's a highly organized system,” Fischer said. "We are really defining the leaf beyond just, carbon dioxide goes in, water comes out.” 

The motivation for the study came from a fundamental tradeoff that every land plant faces. During photosynthesis, plants take in carbon dioxide through tiny pores in their leaves called stomata. For each molecule of CO2 that enters the plant through the stomata to be captured by photosynthesis, 300-400 water molecules escape from the interior of the leaf through the stomata to the atmosphere. A hot, bright day is good for photosynthesis, but terrible for water loss as corn and other crops “sweat it out.” This loss of water is why crops only grow in times and places with adequate rainfall. One of the research team’s primary goals is to develop crop plants that handle this tradeoff better. 

“We're trying to minimize how many water molecules escape while CO2 is going into the leaf to be captured by photosynthesis,” Leakey said. Leakey is also the director of the US Department of Energy-funded Center for Advanced Bioenergy and Bioproducts Innovation, which developed plants with fewer stomata that were examined in the new study. “We've engineered plants that have fewer stomata and demonstrated proof of concept for that goal . . . But now we're really interested in quantifying how easily a CO2 molecule can work its way through the interior ventilation system of the leaf to the location where it actually gets captured by photosynthesis.” 

To answer this question, the team needed what any engineer needs; schematics of how the system currently works. For most plants, such detailed knowledge of the internal anatomy of a leaf simply doesn’t exist. The structures inside can only be truly understood in three dimensions, so traditional two-dimensional images from microscopes are not ideal.  

Fischer and Leakey seized the chance to apply a high-resolution three-dimensional method called micro-computed tomography that could reveal the path of air flow through an intact, living sorghum leaf. They formed a collaboration with Yale University plant physiological ecology professor Craig R. Brodersen and Guillaume Théroux-Rancourt, assistant director of the agronomy research company Biopterre. Brodersen and Théroux-Rancourt had previously helped to innovate microCT imaging for plant tissue samples. 

MicroCT works on the same principle as the CT scan one might get as part of a medical diagnostic process. A series of x-ray images are taken and then combined to form a three-dimensional view of a structure or tissue. Imaging smaller structures requires stronger and more focused x-ray beams than most CT machines can generate. However, these types of x-rays are emitted as a by-product—an incredibly valuable one—of particle accelerator facilities used for atomic physics research. To image their sorghum samples, the research team obtained time at Argonne National Laboratory’s DOE-funded Advanced Photon Source. 

Once the images were acquired and assembled, with the help of machine learning, into high-resolution three-dimensional models, the researchers were surprised by what they found when comparing plants with more or fewer stomata. 

“We thought it was something that would be a challenge for us from the engineering perspective . . . reducing the number of stomata was going to mean that there's a longer, more tortuous path to get CO2 where it’s going,” Leakey said.  

Instead, they found that in leaves with fewer stomata, air spaces beneath them were larger, resulting in equivalent conductance of CO2 through the leaf, meaning that water loss could be reduced without a parallel loss of CO2 distribution to photosynthetic cells. This is good news for further development of drought-stress avoiding plants. 

“There are loads of compensatory mechanisms where we're doing this kind of engineering that make our life difficult,” Leakey said. “This was the first one that was making our life easier.” 

Another surprising result was that stomata on the upper surface were positioned over veins rather than between them, as usually occurs to allow more space for internal air spaces to channel CO2 to photosynthetic cells. 

“This finding opened our eyes to how the two leaf surfaces may contribute differently to uptake of CO2 for photosynthesis and cooling of the leaf through water loss,” Leakey said. “So we want to know, why is it organized like that and how can we leverage that knowledge to make more water use efficient crops that can avoid drought-induced yield losses? That’s the exciting next step.” 

Fischer and Leakey are considering how future studies could answer these and other questions, bringing crop development closer to water use efficiency. In addition to funding by the DOE, the present work was supported by the Howard and Maryam Newman Plant Science Fund. 

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Journal

PLANT PHYSIOLOGY

DOI

10.1093/plphys/kiag414 

Method of Research

Imaging analysis

Subject of Research

Cells

Article Title

High-resolution microCT reveals relationships between stomata and interior leaf anatomy in sorghum

 

Turning on a root-growth switch in tomatoes could fortify crops against drought

Nanjing Agricultural University The Academy of Science

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A proposed model of SlTPP1 enhances drought tolerance by modulating the root/shoot ratio (R/S) in tomato.

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Credit: Horticulture Research

Drought is the single greatest threat to global crop production, and helping plants survive with less water has become a race against climate change. Now, researchers have uncovered a molecular switch in tomato that shifts the plant's energy balance toward its roots—the frontline organs for water capture—while holding back shoot growth. The discovery pinpoints a regulatory circuit involving a sugar-metabolizing enzyme and a transcription factor that together determine how tomato plants redistribute resources under water-limited conditions. The work offers a precise genetic target for breeding more drought-resilient crops without sacrificing overall biomass.

When water runs short, plants that invest more biomass in roots relative to shoots stand a better chance of survival. A higher root-to-shoot ratio (R/S) means greater water uptake capacity and less transpirational loss—a strategy observed across diverse crops from wheat to rice to sorghum. Yet the molecular machinery that controls this critical balance has remained largely elusive. Trehalose-6-phosphate phosphatase (TPP) enzymes are known to influence sugar signaling and stress responses, but whether and how they directly modulate root-versus-shoot allocation has been unclear. Based on these challenges, there is an urgent need for in-depth research into the specific regulators that orchestrate this adaptive rebalancing.

A team led by researchers at the State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, in collaboration with Xinjiang Agricultural University and Beijing University of Agriculture, reports (DOI: 10.1093/hr/uhag070) these findings in Horticulture Research (Volume 13, Issue 6, June 2026). The study reveals that a tomato gene called SlTPP1 acts as a positive regulator of drought tolerance by increasing root growth and elevating the R/S. Conversely, the transcription factor SlERF4 suppresses SlTPP1 expression, undermining the plant's ability to reallocate resources when water is scarce.

The researchers found that drought stress dynamically pulls SlTPP1 expression in opposite directions—ramping it up in roots while shutting it down in leaves. When they overexpressed SlTPP1 in tomato, the plants channeled more dry matter into their roots, significantly increasing the R/S and maintaining higher leaf water content under drought. At night, when sugar transport from leaves to roots peaks, SlTPP1 overexpression boosted soluble sugar accumulation in roots and upregulated a suite of cell wall biosynthesis genes, driving root elongation. Meanwhile, in leaves, SlTPP1 overexpression silenced key components of the ethylene signaling pathway, further tipping the balance toward root investment. The team then identified SlERF4 as the direct repressor of SlTPP1: this transcription factor binds to a specific element in the SlTPP1 promoter and turns off its expression. Knocking out SlERF4 with CRISPR/Cas9 released SlTPP1 from repression, boosting R/S and drought tolerance. Importantly, drought enhanced ethylene production in leaves but suppressed it in roots, creating a tissue-specific signal that drives the opposing expression of these two genes.

"The most exciting part is seeing how a single gene can coordinate such a sophisticated strategy across different organs," the authors said. "By increasing sugar accumulation in roots and dialing down ethylene signaling in leaves, SlTPP1 essentially tells the plant to invest below ground when water is scarce. And the fact that SlERF4 sits upstream as a brake on this system gives us a clear on-off switch to manipulate. We think this module could be a game-changer for breeding—not just in tomato, but potentially in other crops that rely on the same fundamental pathways."

The findings open a direct path to engineering drought-tolerant tomatoes through precision breeding or gene editing. Because SlTPP1 overexpression increases R/S without reducing total biomass, it sidesteps the yield penalty that often accompanies stress tolerance traits. The same regulatory logic may apply to other staple crops: TPP genes are conserved across plants, and ERF transcription factors are widespread regulators of stress responses. By fine-tuning this module, breeders could tailor root architecture to specific environments—deeper roots for dryland farming, for example, or more balanced partitioning for irrigated systems. As climate volatility intensifies, such targeted interventions will be essential for safeguarding food production. The study also provides a molecular framework for understanding how plants integrate sugar status, hormone signals, and organ-specific gene expression to survive drought—knowledge that could inspire entirely new strategies for crop improvement.

###

References

DOI

10.1093/hr/uhag070

Original Source URL

https://doi.org/10.1093/hr/uhag070

Funding information

This research was supported by the National Key Research and Development Program of China (2023YFD2300700, 2021YFD1600300, and 2024YFD2300702), China Agriculture Research System (CARS-23-B07), and the National Natural Science Foundation of China (Grant No. 32502804).

About Horticulture Research

Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.

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Journal

Horticulture Research

DOI

10.1093/hr/uhag070 

Subject of Research

Not applicable

Article Title

A SlERF4–SlTPP1 module enhances drought tolerance in tomato by increasing the root/shoot ratio

Article Pub

Kenya’s Rift Valley residents reach breaking point: 'The lake moved into my house’

With Kenya’s Lake Baringo and Lake Bogoria rising for months now, following above-average rainfall across the Rift Valley over recent years, this summer has seen them – and the communities around them – reach tipping point.


Issued on: 19/07/2026 - 

Kenya's Lake Baringo has been rising for several months, following above-average rainfall. © Environmental and Climate Change Group

By: Anne Macharia in Nairobi

Samuel Loruman points past the bow of his rowboat, toward a shifting green mat of water hyacinth.

His father's cattle boma – a livestock enclosure – once stood there. Now there is only water. Beneath it, he says, the fence posts are still standing.

"I did not move house," he says, as he rows over what used to be his family's grazing land near Kampi Samaki. "The lake moved into my house."

Since 2011, Lake Baringo and its smaller neighbour, Lake Bogoria, have risen dramatically, tied to above-average rainfall.


In May this year the situation reached tipping point, with the water swallowing up farms, schools, a health centre and long stretches of shoreline road.

Loruman, 43, grew up herding goats and growing sorghum on land his grandfather cleared. That land now sits roughly 4 metres underwater.

He earns his living differently these days, paddling a hand-built boat out to fish tilapia, the way lakeside families do.

"My father would not recognise me holding a net instead of a herding stick," he says. "At the beginning, it felt like becoming nobody."

He has since built a new home for himself. He also sits on a community committee allocating fishing zones, and has taught a dozen former farmers how to read the water.

"The lake has weather the way the sky has weather," he says. "Nobody taught me this. The lake taught me, usually by nearly killing me first."

'A hydrological puzzle'

Professor Simon Onywere, a geologist and spatial environmental planner at Kenyatta University who has studied the Rift Valley lakes for more than a decade, has documented the scale of the flooding in detail.

"The lakes are responding to several forces acting at the same time. Rainfall is only one piece of a much larger hydrological puzzle," he said.

Onywere's research points to a pattern rather than a single cause, which other scientists studying the lakes have also struggled to isolate.

"People often ask what caused the lakes to rise. The honest scientific answer is that no single factor explains what we're seeing," agrees Dr. Joyce Kimutai, a climate scientist at Kenya's Meteorological Department.

Part of the issue, researchers say, lies well beyond the lakes – in what's happening to the land that feeds them.

"The catchments have changed dramatically over the last few decades. When forests are cleared and soils are exposed, more sediment reaches the lakes, reducing their storage capacity," says Moses Macharia, chair of Friends of Nairobi National Park.

That loss of storage capacity is turning a naturally cyclical lake system into a fast-moving crisis for the people living beside it.

"These lakes have always fluctuated, but the speed and scale of recent changes have left communities with very little time to adapt," says Mbugua Githae, a structural geologist and mineral exploration consultant with Innercore Geoconsultants.

Behind all of it, scientists say, sits a broader climate signal that is making these swings more frequent and more extreme.

"Climate change doesn't act in isolation. It amplifies existing natural variability, making extreme wet periods more likely," said Professor Christopher Shisanya, an expert in agro-climatology at Kenyatta University.

The Kenya Meteorological Department is warning of an 80 percent probability that El Niño-related rains will develop later this year, peaking from October to December, raising fears the waters will rise more still.

'He will inherit water'

More than 40,000 people have been displaced across Baringo North, South and Tiaty sub-counties as the lakes have swollen, according to humanitarian agencies.

Some have rebuilt their homes three or four times as the shoreline continues to advance.

"You learn not to build anything you love too close to the water," Loruman says. "My mother's kitchen was rebuilt twice. She cried both times. By the third house, she just supervised the builders and didn't look back."

He rows on past the submerged boma without slowing, checking a line of nets, hauling up two silver tilapia that thrash in the bottom of the boat.

"People ask if I miss the cattle. I tell them the lake took my father's life and gave me my son's."

His son has never herded a goat and Loruman says, could swim before he could walk.

"He will inherit water, not land, and he doesn't grieve that the way I did," he says. "Maybe that's the difference between his generation and mine. He was never asked to mourn something he never had."

In Zimbabwe, community seed banks are reviving indigenous crops

Mutare, Zimbabwe – Zimbabwean farmers are reviving drought-resistant traditional crops through a community seed bank, helping them cope with worsening climate variability. The initiative, rooted in indigenous knowledge, is strengthening food security and offering a safety net against future droughts and floods.


Issued on: 12/07/2026 - RFI

Smallholder farmers sorting seeds of small grains in Chipinge, Zimbabwe. © FAO

By:  Farai Shawn Matiashe

Angeline Garwe monitors smallholder farmers bringing small grain seeds to a community seed bank after harvest in Chipinge, southeastern Zimbabwe.

She checks whether the names on the tags correspond with the variety of the seeds and records all the details in her file.

The 49-year-old woman from Kubatana Village is one of nearly 1,000 farmers who have established the Dumisai community seed bank, where they preserve seeds.

Some traditional crop varieties are on the verge of extinction as hybrid crops take over

Through the seed bank, farmers can access seeds for years to come.

Some of the seeds stored in a community seed bank in Chipinge, Zimbabwe. © FAO

Climate resilience

Garwe said she has been experiencing the effects of climate change for the past decade.

"I remember we used to plant in late October. But now, late rains force us to plant in late November and December," she told RFI.

"It was devastating to see plants wilting because of drought."

Zimbabwe is experiencing drought and floods, worsened by the effects of climate change.

In 2024, the country experienced an El Niño-induced drought that led to crop failure, forcing the government to declare a national disaster to mobilise resources to support struggling families.

Climate change 'supercharging' deadly floods in southern Africa

This punishing drought also destroyed some of Garwe's crops. The farmers face not only increasing climate variability but also declining soil fertility and the loss of indigenous crop varieties as they shift to high-yielding commercial seeds.

The United Nations' Food and Agriculture Organization (FAO) and the Global Environment Facility (GEF) funded the setup of the community seed bank in 2024 to promote drought-resistant crops and conserve locally adapted seeds of traditional crop varieties such as sorghum, millet and cowpeas.

Patrice Talla, FAO subregional coordinator for southern Africa, said the community seed bank is deeply rooted in indigenous knowledge systems.

"It builds on generations of farmer knowledge related to seed selection, preservation and adaptation to local agro-ecological conditions," he said.

"Farmers contribute traditional varieties that are often better adapted to local climates and soils, as well as knowledge on planting cycles, storage techniques and crop uses."

Some traditional crop varieties are short-term and survive with minimal water, ensuring farmers harvest enough to feed their families during droughts.

These small grains are drought resistant and can survive in dry areas. © FAO

Food security

Garwe, a mother of five, said the seed bank is helping to multiply locally adapted traditional crop varieties and strengthen food sovereignty.

"This year the rains were erratic, but I harvested enough to feed my family and sell the excess to other villagers," she said.

Talla said the community seed bank in Chipinge district is strengthening both food security and climate resilience by improving farmers' access to diverse, locally adapted seed varieties.

"By conserving and multiplying traditional crops such as small grains, legumes and drought-tolerant varieties, the seed bank helps farmers reduce dependence on external seed systems and enhances their capacity to cope with climate variability, including erratic rainfall and prolonged dry spells," he said.

"It also promotes crop diversification, which improves dietary diversity and reduces the risk of total crop failure. In this way, the initiative contributes to more stable household food availability and supports resilient farming systems."

FAO and its partners are supporting the replication and scaling-up of community seed bank models in other parts of Zimbabwe, particularly in areas vulnerable to climate shocks.

Smallholder farmers planting traditional grains in a field in Chipinge. © FAO

Harare goes green: capital city leads Zimbabwe’s climate fight with bold urban solutions

Insurance during disasters

Chipinge is vulnerable to floods. In March 2019, it was among the areas of eastern Zimbabwe hit by the deadly Cyclone Idai, which destroyed fields and infrastructure.

A seed bank like Garwe's offers a kind of insurance during such disasters. Farmers can access seeds stored in the seed bank to revive their farms.

Another smallholder farmer at the Dumisai community seed bank, Anna Ndabare, 50, said the seed bank helps conserve traditional small grains.

"When drought or floods destroy my fields, I have a place to turn to," she said.

Talla said continued operation depends on strong community governance and long-term support mechanisms, and that extreme climate events, which can still affect seed regeneration, remain a challenge for community seed banks.

For Garwe, community ownership of Dumisai is central to its sustainability.

"The community will protect it. We all want to see it thriving," she said.

French farmers race to adapt as repeated heatwaves hit crops and livestock

After weeks of sweltering heat and drought, farmers and analysts fear France's maize crop could be down by a third this year – making it the smallest in 35 years. Poultry farmers are also counting their losses as many as 3 million broiler chickens died within a few days in in June. The damage is a result of three heatwaves that have already hit France this year, and is only set to intensify as climate change disrupts agriculture across Europe.


Issued on: 11/07/2026 - RFI

An irrigation sprinkler sprays water on a corn field in Parigne-l'Eveque near Le Mans on 8 July, 2026, as drought worsens in Sarthe department during a heatwave affecting a large part of the country. © Benoit Tessier / REUTERS


Temperatures have climbed above 40C in parts of France and elsewhere in Europe, affecting both crops and livestock.

Harvests have started much earlier than usual in several regions, reflecting a longer-term trend linked to global warming.

"The weather station on the farm is showing 38.8C," says David Vincent, who grows almost 200 hectares of cereals in the southern department of Aude.

"The heatwaves since May have accelerated the end of the growing cycle for all our crops. So we started harvesting 15 days earlier than we used to. Clearly, our yields are down today," he told RFI.

Winter rainfall helped replenish soil moisture, allowing crops to grow normally through spring. But the rain stopped in April.

The harvest could potentially have been good at the beginning of May, Vincent said, but "by June, when we started harvesting, it was down by 10 percent to 30 percent in my area".

Vincent grows a wide range of crops – durum wheat, soft wheat, barley, protein peas, sorghum, maize, sunflower and rapeseed.

He said diversifying crops had become the best way to adapt to increasing climate uncertainty in the southern Occitanie region.

'I thought I was ready'

Livestock farmers have also been badly affected. Agriculture Minister Annie Genevard told the Senate that 9,127 tonnes of dead animals, mainly poultry, had been collected by the state after the heatwave at the end of June.

The worst-hit livestock farms are in western France, and with a third heatwave now affecting much of the country, many farmers fear further losses.

Pig farmer Bertrand Feugnet, from Rouillac in western France, said he had been anxious when temperatures of 43C were forecast.

"It's true that 15 days ago, when they announced 43C – which we did get – I was really worried about how the animals were going to react."

He said one neighbouring farmer lost 17 sows while they were giving birth in buildings where temperatures reached 34C. Thanks to a cooling mist system that lowered temperatures inside his buildings, Feugnet himself lost only three of his piglets.

Organic cattle farmer Éric Germon, who raises Limousin cattle, said even his more traditional farming model was no longer protected from extreme heat.

"I thought I was ready for 2050 and I realise that even I am suffering. But we'll still have a head start, we'll suffer less than others," Germon said.

His working day now starts at 5:30 in the morning so he can move his cattle before temperatures rise. Although he rests during the afternoon, he said the long days were becoming exhausting.


'We'll face shortages'

Extreme weather including flash droughts and torrential rain is expected to become more common as the climate warms, said Inaki Garcia de Cortaza Atauri, an agronomist and research director at the French National Research Institute for Agriculture, Food and Environment (INRAE).

"Within five or 10 years, these types of events are going to become more and more the norm and if we don't adapt, we're going to have problems, such as plants stopping growing," he said. "The quality of harvests will deteriorate, and production in general. At some point, we'll face shortages."

He said farmers would need to diversify crops, change crop rotations, alter growing cycles and improve soils so they retain water for longer.

The challenge, he said, is to spread those practices as widely as possible so farming can continue despite rising temperatures.

Firefighters work to extinguish a fire near a farm in Grand-Auverné, in the west of France, 30 June 2026. @ REUTERS - Stephane Mahe

A Europe-wide issue

The European Union estimates that recent heatwaves have caused 3,500 excess deaths.

Climate Commissioner Wopke Hoekstra said productivity had fallen, schools had closed, harvests had been damaged, hospitals had come under pressure and roads and railways had been damaged.

On Wednesday, the European Parliament debated the EU's response to increasingly frequent wildfires. Beyond emergency measures, the bloc is also reviewing how it adapts to climate change.

The EU has activated its Civil Protection Mechanism nearly 20 times in recent months to respond to wildfires linked to heatwaves. It is also funding projects including urban greening to reduce heat in cities.

The European Environment Agency says Europe is the fastest-warming continent and faces 36 major climate risks covering ecosystems, food, health, infrastructure, the economy and finance.

The EU's 2021 climate adaptation strategy, which is not legally binding, is due to be replaced in 2026 by an integrated climate resilience framework. It is expected to include recommendations for protecting workers during periods of extreme heat.

Biochar-powered hydrogels boost solar water evaporation efficiency for sustainable desalination

Biochar Editorial Office, Shenyang Agricultural University

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Heat loss and water transport capacity regulation in hybrid evaporators

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Credit: Sihui Wang, Jiaqi Yang, Aijie Wang & Wenzong Liu

A new study reveals how combining biochar with advanced hydrogels can dramatically improve solar-driven water evaporation, offering a promising pathway for low-energy desalination and water purification technologies.

Freshwater scarcity is a growing global challenge, with most of Earth’s water locked in oceans or saline sources. Traditional desalination methods often require high energy input and infrastructure costs. Solar interfacial evaporation, which uses sunlight to convert water into vapor at the surface, has emerged as a cleaner and more energy-efficient alternative. However, improving its efficiency remains a key scientific challenge.

In a recent study published in Biochar, researchers developed a hybrid material that integrates biochar into a polyzwitterionic hydrogel, achieving a remarkable evaporation rate of 3.57 kilograms per square meter per hour under standard sunlight conditions. This performance is significantly higher than that of conventional hydrogels and highlights the potential of biochar-based materials in sustainable water treatment.

“By introducing biochar into the hydrogel network, we were able to simultaneously enhance light absorption, water transport, and energy efficiency,” said the study’s corresponding author. “This multi-functional synergy is key to achieving high-performance solar evaporation.”

The innovation lies in how biochar interacts with the hydrogel at both physical and molecular levels. Biochar, a carbon-rich material derived from biomass such as agricultural waste, is known for its porous structure and strong light-absorbing properties. When incorporated into the hydrogel, it transforms the material from transparent to dark, enabling it to capture more sunlight across a wide spectrum. According to experimental results, the hybrid hydrogel maintained over 95 percent light absorption across a broad wavelength range.

At the same time, the addition of biochar alters the internal structure of the hydrogel. Microscopic observations, shown in figures on page 4 of the paper, reveal a denser and more interconnected pore network. This structure improves the movement of water within the material, ensuring a continuous supply of water to the evaporation surface while minimizing heat loss to the bulk liquid.

Beyond photothermal effects, the study also uncovers a less explored mechanism involving water molecule behavior. The surface functional groups of biochar interact with the hydrogen bonding network inside the hydrogel, increasing the proportion of so-called intermediate water. This form of water requires less energy to evaporate compared to tightly bound water. As a result, the hybrid material significantly reduces the energy needed for evaporation, lowering the equivalent evaporation enthalpy to 877.79 joules per gram.

This dual enhancement, combining photothermal efficiency with molecular-level water activation, enables the hybrid hydrogel to outperform many existing materials. The system also demonstrates strong water transport capabilities even in saline conditions, making it particularly suitable for seawater desalination applications.

The researchers emphasize that biochar is not only effective but also sustainable and cost-efficient, as it can be produced from agricultural residues such as sorghum straw. This adds an important environmental advantage, aligning the technology with circular economy principles.

“Our findings provide new insights into how material design can address multiple bottlenecks in solar evaporation systems,” the authors noted. “This could guide the development of next-generation evaporators for clean water production in resource-limited settings.”

As global demand for freshwater continues to rise, innovations like biochar-enhanced hydrogels could play a critical role in delivering scalable, low-carbon water treatment solutions.

 

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Journal Reference: Wang, S., Yang, J., Wang, A. et al. Heat loss and water transport capacity regulation in hybrid evaporators. Biochar 8, 97 (2026).   

https://doi.org/10.1007/s42773-026-00604-0  

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About Biochar

Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field. 

Follow us on Facebook, X, and Bluesky.  

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Journal

Biochar

DOI

10.1007/s42773-026-00604-0 

Method of Research

Experimental study

Article Title

Heat loss and water transport capacity regulation in hybrid evaporators

Article Publication Date

27-Apr-2026

Turning “wastewater” into a resource: New insights on liquid fertilizer from hydrothermal carbonization

Biochar Editorial Office, Shenyang Agricultural University

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Process water from hydrothermal carbonization: from waste to liquid fertilizer and soil health amendment in circular bioeconomy

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Credit: Qingnan Chu, Xiangyu Liu, Yanfang Feng, Detian Li, Shuai Yin, Chengrong Chen & Zhimin Sha

A growing body of research is redefining how scientists view a once-overlooked byproduct of biomass processing. A new review published in Biochar reveals that process water generated during hydrothermal carbonization, long treated as waste, could play a key role in sustainable agriculture and the circular bioeconomy.

Hydrothermal carbonization is an emerging technology that converts wet organic materials such as food waste, sewage sludge, and agricultural residues into a carbon-rich solid known as hydrochar. While much attention has focused on this solid product, the accompanying liquid fraction, called process water, has remained largely underutilized. According to the authors, this liquid can account for up to 70 percent of the original material and contains substantial amounts of nutrients and organic compounds.

“This process water is not just a byproduct. It is a nutrient-rich resource with significant potential for agriculture,” said the study’s corresponding author. “Our work highlights how it can be transformed from a disposal challenge into a valuable input for crop production and environmental management.”

The review synthesizes findings from recent studies on the composition and applications of this liquid. It shows that process water contains high levels of nitrogen, phosphorus, potassium, and organic carbon. These components are essential for plant growth and can support its use as a liquid fertilizer or soil amendment. In some cases, applying diluted process water has increased crop yields by up to nearly 30 percent and improved nutrient use efficiency by 15 to 30 percent in crops such as rice.

Beyond direct fertilization, the liquid can also be integrated into broader resource recovery systems. For example, nutrients can be extracted through processes such as struvite precipitation, which recovers phosphorus and nitrogen for reuse. The organic content can also be converted into energy through anaerobic digestion, producing methane-rich biogas. These approaches align with circular economy principles by reducing waste and maximizing resource efficiency.

However, the study also emphasizes that careful management is required before agricultural use. Process water can contain compounds such as organic acids, phenols, and salts that may inhibit plant growth if applied without treatment. Strategies such as dilution, co-application with other organic inputs, or pre-treatment methods like neutralization and filtration can significantly reduce these risks.

The authors note that operational conditions during hydrothermal carbonization strongly influence the quality of the process water. Factors such as temperature, reaction time, and feedstock type can be adjusted to tailor nutrient content and reduce harmful components. This opens the door to designing customized liquid fertilizers suited for specific crops and farming systems.

Importantly, the review highlights broader environmental benefits. Using process water as a fertilizer substitute can reduce reliance on synthetic fertilizers and lower greenhouse gas emissions. Life cycle assessments suggest that such substitution may cut global warming impacts by up to 50 percent under certain scenarios.

Despite these promising findings, the authors call for more long-term field studies and large-scale demonstrations. Questions remain about variability across feedstocks, long-term soil impacts, and regulatory frameworks for safe application.

Overall, the research signals a shift in perspective. What was once considered wastewater is now being reimagined as a multifunctional resource that supports sustainable agriculture, renewable energy, and waste reduction.

“This is a step toward closing nutrient loops and building more resilient agricultural systems,” the authors conclude.

 

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Journal Reference: Chu, Q., Liu, X., Feng, Y. et al. Process water from hydrothermal carbonization: from waste to liquid fertilizer and soil health amendment in circular bioeconomy. Biochar 8, 96 (2026).   

https://doi.org/10.1007/s42773-026-00614-y   

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About Biochar

Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field. 

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Journal

Biochar

DOI

10.1007/s42773-026-00614-y 

Method of Research

Literature review

Article Title

Process water from hydrothermal carbonization: from waste to liquid fertilizer and soil health amendment in circular bioeconomy

Article Publication Date

27-Apr-2026