Thursday, January 08, 2026

Heatwaves heat up soil but not toxin levels in rice, study finds

Biochar Editorial Office, Shenyang Agricultural University

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Elevated soil temperatures during a heatwave year do not necessarily increase metal(loid) mobilization or accumulation across two harvests of semi-perennial rice: evidence from mesocosm experiments
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Credit: Qianrui Huangfu, Sha Zhang, Yuang Guo, Lu Wang, Zheng Chen, & Shuai Du

In a surprising twist amid rising climate concerns, new research shows that scorching soil temperatures during extreme heatwaves do not necessarily boost the uptake of toxic elements like arsenic in rice crops. This finding, from a real world experiment during China's record breaking 2022 heatwaves, challenges fears that global warming will poison staple foods.

"Our study reveals that soil warming alone, decoupled from air temperature rises, does not inevitably ramp up arsenic or heavy metal accumulation in rice grains," said Sha Zhang, lead researcher at the Chinese Academy of Sciences' Institute of Urban Environment and corresponding author of the paper. "This provides reassurance for food safety under future climate extremes, as plant biology and seasonal factors play bigger roles than previously thought."

Published today in Environmental and Biogeochemical Processes, the study used innovative outdoor tanks to mimic paddy fields and test soil heating from direct sunlight. Researchers grew a special type of rice called ratoon rice, which yields two harvests from one planting: a main crop and a second ratoon crop from the stubble. This setup allowed them to observe effects over an extended 143 day growing season.

The experiment took place in Suzhou, China, using large aboveground tanks filled with local paddy soil low in contaminants. Each tank had a sun exposed south side and a shaded north side, creating a natural soil warming gradient of about 5.65 degrees Celsius on average at 5 to 10 centimeters depth. Crucially, air temperatures above the plants stayed identical across sides, isolating soil effects from canopy heat stress.

Three intense heatwaves hit during the 2022 season, with air temperatures topping 36 degrees Celsius for days at a time. Soil on the warmed sides baked even hotter due to solar radiation. Despite this, porewater arsenic levels – a key measure of availability to plants – showed no significant differences between warmed and control plots in either crop (p > 0.05). While arsenic in soil water jumped tenfold from main crop (average 6.9 micrograms per liter) to ratoon crop (576.6 micrograms per liter), rice grain levels rose only modestly, from 89.8 to 123.7 micrograms per kilogram.

The team analyzed 16 elements, including toxins like arsenic, cadmium, antimony, thallium, and lead, plus nutrients such as iron, zinc, and magnesium. Warming did not spike most heavy metals in grains or porewater. Arsenic translocation from plant nodes to grains was higher in the ratoon crop, but overall accumulation stayed in check, likely due to root uptake limits early in growth.

"This decouples soil mobilization from grain contamination," noted Zheng Chen, co corresponding author at Xi'an Jiaotong Liverpool University. "Flooded conditions buffered short term heat impacts, and rice physiology acted as a natural safeguard."

Previous studies linked warming to higher arsenic via air heated setups or lab simulations, raising alarms for rice eating billions in Asia. But those often mixed soil and air effects, or ignored plant defenses like root barriers and internal storage.

Ratoon rice, popular in southern China for efficiency, faces extra scrutiny as the second crop grows in late summer heat. Yet here, soil heat did not worsen risks. Magnesium in grains even dropped on warmed plots, while other nutrients held steady.

The findings urge refined climate models distinguishing soil from air warming. "Soil heat extremes can outpace air ones, so we need field relevant tests," Zhang added. Funded by China's National Key Research Program, the work calls for multi year studies across sites.

As heatwaves intensify – with 2022's Yangtze events among the worst – this research eases some food safety worries. Rice supplies over half the calories for 3.5 billion people, and arsenic threatens health from cancer to child development.

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Journal reference: Huangfu Q, Zhang S, Guo Y, Wang L, Chen Z, et al. 2025. Elevated soil temperatures during a heatwave year do not necessarily increase metal(loid) mobilization or accumulation across two harvests of semi-perennial rice: evidence from mesocosm experiments. Environmental and Biogeochemical Processes 1: e017

https://www.maxapress.com/article/doi/10.48130/ebp-0025-0017

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About the Journal:

Environmental and Biogeochemical Processes (e-ISSN 3070-1708) is a multidisciplinary platform for communicating advances in fundamental and applied research on the interactions and processes involving the cycling of elements and compounds between the biological, geological, and chemical components of the environment.

DOI

10.48130/ebp-0025-0017

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Elevated soil temperatures during a heatwave year do not necessarily increase metal(loid) mobilization or accumulation across two harvests of semi-perennial rice: evidence from mesocosm experiments

New study uncovers how rice viruses manipulate plant defenses to protect insect vectors

Chinese Academy of Sciences Headquarters

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Proposed model illustrating how rice-infecting viruses attenuate indirect defenses against insect vectors.
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Credit: Image by ZHANG Xiaoming' Lab

Planthoppers and leafhoppers not only feed on rice plants but also act as highly efficient vectors for plant viruses, causing substantial yield losses worldwide. Notably, their persistent ability to evade natural enemies is not merely a matter of chance—it is subtly reinforced by the plant viruses they carry.

A recent study led by Prof. ZHANG Xiaoming's team at the Institute of Zoology of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Ian T. Baldwin's group at the CAS Center for Excellence in Molecular Plant Sciences, has uncovered a novel ecological strategy. Rather than passively "hitchhiking" within insect vectors, rice viruses actively manipulate plant defense pathways to protect their insect carriers. This discovery reshapes our understanding of plant–virus–insect–parasitoid interactions and provides new insights for sustainable pest and pathogen management.

The findings were published in Science Advances on January 7.

Under normal conditions, rice plants respond to attacks by small brown planthoppers and other herbivorous insects by releasing methyl salicylate (MeSA), a volatile organic compound that serves as a chemical distress signal. MeSA not only deters herbivorous insects but also attracts natural enemies such as parasitoid wasps. These wasps lay their eggs inside pest eggs, effectively suppressing pest populations and forming a critical line of indirect plant defense.

However, insect-borne viruses such as Rice Stripe Virus, which is transmitted by small brown planthoppers, can disrupt this defense system. Through their NS2 protein, these viruses suppress MeSA biosynthesis and effectively silence the plant's alarm signal. As a result, parasitoid wasps are no longer recruited, and virus-carrying insects gain effective protection. This creates a self-reinforcing cycle: viruses protect their vectors and vectors in turn facilitate viral transmission.

To break this cycle, the researchers conducted large-scale field experiments over two consecutive years in Jurong, Jiangsu Province. By deploying slow-release MeSA dispensers in rice paddies, they restored the disrupted plant signaling. The results showed that parasitoid wasp abundance increased significantly, pest populations declined, and egg parasitism rates rose from approximately 40% in virus-infected fields to over 60%—matching levels observed in virus-free fields. Meanwhile, viral transmission was effectively suppressed.

As MeSA is a natural metabolite produced by rice plants, this strategy is environmentally friendly, free of chemical pollution, and unlikely to induce resistance. Instead of eliminating pests outright, it restores disrupted ecological interactions and reactivates nature's inherent pest control mechanisms.

Journal

Science Advances

DOI

10.1126/sciadv.aeb5215

Digital modeling reveals where construction carbon emissions really come from

Biochar Editorial Office, Shenyang Agricultural University

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A building information modelling study of carbon emissions in the construction industry based on life cycle assessment
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Credit: Xinyu Yang, Yingjie Shi, Basaula Pululu Jordan, Shanzhi Wang, Xuan Cao, Qifan Yue, Yuxuan Li & Yujing Yang

A new study shows how digital building models can be used to pinpoint where carbon emissions occur across a building’s entire life cycle, offering designers and policymakers a powerful tool to reduce the climate footprint of the construction industry.

Researchers developed an integrated method that combines Building Information Modeling and Life Cycle Assessment to calculate carbon emissions from the earliest design stage through construction, operation, and eventual demolition. Using a real office building in China as a case study, the team demonstrated how emissions can be quantified in detail and how targeted reduction strategies can be identified before construction even begins.

The construction sector is one of the world’s largest sources of carbon dioxide emissions, responsible for more than one third of global energy related emissions. In China alone, emissions from construction activities have more than doubled over the past two decades. Despite this impact, accurately estimating emissions across a building’s full life cycle has remained challenging, especially during the design phase when key decisions are made.

“Our goal was to move carbon assessment upstream, into the design stage, where it can actually influence decisions,” said Yujing Yang, corresponding author of the study. “By integrating life cycle assessment directly into a digital building model, designers can see where emissions come from and how to reduce them before a building is constructed.”

The research team created a detailed three dimensional digital model of a three story reinforced concrete office building. They linked this model to a carbon emission estimation tool that calculates emissions from four major stages: material production and transportation, construction, operation and maintenance, and demolition. The model follows international life cycle assessment standards and uses region specific data for materials, energy use, and transportation.

The results reveal that emissions are not evenly distributed across a building’s life cycle. Material production emerged as a major contributor, with steel, concrete, and cement accounting for the largest share. Steel alone was responsible for nearly half of the emissions from material production. Transportation also played a significant role, particularly for bulk materials such as sand, where long transport distances greatly increased emissions.

“Our findings show that transportation distance can matter just as much as the material itself,” Yang said. “Sourcing materials locally has enormous potential to cut emissions, especially for heavy materials like sand.”

The study also found that operational emissions dominate over the long term, largely due to heating and energy use during the building’s lifetime. In the case study, heating related emissions accounted for nearly two thirds of total operational emissions. This highlights the importance of clean heating technologies, improved insulation, and energy efficient building design.

By running sensitivity analyses, the researchers showed how changes in transportation distance, vehicle type, and material sourcing could dramatically reduce emissions. In some scenarios, transportation related emissions were reduced by more than 70 percent simply by switching to local suppliers and lower emission vehicles.

The researchers emphasize that the approach is not limited to a single building or region. Because it relies on widely used BIM platforms and standardized life cycle assessment methods, it can be applied to a wide range of building types and locations.

“This study provides a practical roadmap for low carbon building design,” Yang said. “It shows that digital tools can turn climate goals into concrete design choices, helping the construction industry move toward a more sustainable future.”

The findings provide a valuable reference for architects, engineers, developers, and policymakers seeking to reduce carbon emissions from buildings while maintaining performance and cost efficiency.

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Journal reference: Yang X, Shi Y, Jordan BP, Wang S, Cao X, et al. 2025. A building information modelling study of carbon emissions in the construction industry based on life cycle assessment. Energy & Environment Nexus 1: e015

https://www.maxapress.com/article/doi/10.48130/een-0025-0014

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About Energy & Environment Nexus:
Energy & Environment Nexus (e-ISSN 3070-0582) is an open-access journal publishing high-quality research on the interplay between energy systems and environmental sustainability, including renewable energy, carbon mitigation, and green technologies.

DOI

10.48130/een-0025-0014