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Winter time: Cucumber water instead of road salt: Why salting against slippery surfaces is harmful and what alternatives there are News (indonewyork.com)

Anyone who fought their way through the snow chaos in Bavaria in the last few days couldn't help but see at least one walker slip. The winter clearance services were barely able to keep up with the masses of snow; now the ice has melted on its own. What remains is road salt that harms the environment. An innovative alternative has been available in Bavaria for a few years now - cucumber water. But you should also generally avoid salts altogether if possible. However, according to the Federal Environment Agency, more than four million tonnes end up on our streets and pedestrian paths in harsh winters. Road salt consists mainly of sodium chloride - that is normal table salt -, calcium or magnesium chloride. The salt reduces the freezing point and thus the ice on the paths or prevents it from forming at all. However, it is ineffective at temperatures below minus 20 degrees, and the same applies to continuous snowfall. The road salt flows into the canal system or reaches rivers, streams, lakes and groundwater via meltwater and puts a strain on the ecosystem. The salt can burn plants on the side of the road. Seeping road salt can accumulate in roadside soils for many years. The damage may be delayed for years. If the salt content is too high, important nutrients are washed out, it becomes more difficult for plants and trees to absorb nutrients and water, and they become more susceptible to diseases or dry out. In dogs, cats or other animals, the salt can get stuck in the paws and cause inflammation. The salts also attack vehicles and structures - this is particularly problematic in the case of monuments or corrosion damage to bridges. Property owners must ensure that sidewalks are cleared and there is a high risk of liability in the event of accidents. The basis is §823 of the Civil Code (BGB). For many people, salting the sidewalk is therefore out of the question. Only: In many communities, the private use of road salt is prohibited - with the exception of stairs or similarly critical areas. Anyone who violates this must expect fines. However, there is no uniform regulation at federal and state level. BUND Nature Conservation criticizes the fact that hardware stores continue to sell road salt.

In Bavaria there is a pilot project run by the Bavarian State Building Administration and the Develey company in Dingolfing, Lower Bavaria. The company has been using salt water from cucumber production since 2019 and makes it available for winter service. The brine that is created during the production of pickles is actually disposed of. By the way, this is wastewater - and explicitly not the sour cucumber water in the glass. Nobody has to worry about the smell on the streets either. So that the salt can be used for winter service, it is cleaned and processed into brine. To this end, the road maintenance department in Dingolfing will increase the concentration from 7 to 21 percent and use it in surrounding districts. In this way, the company does not have to laboriously dispose of its salt water and, thanks to the more environmentally friendly brine, less salt ends up in nature. This saves 90 tons of salt per 1,000 tons of brine used. By using cucumber water, up to 180 tons of road salt and almost a million liters of water can be saved every year. The only problem is that this is still salt. And the brine from the cucumber water also pollutes the environment. Another method has been found in the USA. Here, too, there is salt in the mix, but beet syrup is particularly popular in the north. For example, in Washington D.C. or in Canada, beet juice is sometimes combined with salt. According to the Washington Post, the mixture consists of 23 percent salt, 62 percent water and 15 percent beet syrup. And it is said to be at least as effective as the much better known road salt. The method was discovered by a Hungarian scientist in the 1990s. In recent years they have discovered more and more cities for themselves. Because the mixture is so sticky, it stays on the road longer and, unlike road salt, works even at very low temperatures. But the beet syrup could also be harmful to insects - but it is probably still more environmentally friendly than pure road salt. Instead of salting, BUND Nature Conservation or NABU recommend so-called blunting agents, i.e. grit, chips or sand. This doesn't melt the ice, but it does make it less slippery. But it takes a lot, according to the Federal Environment Agency, around 100 grams per square meter. And that's why the energy requirement for blunting agents could be higher than for road salt. “The effort for collecting and, if necessary, cleaning at the end of the season must also be taken into account in the energy balance,” says the Federal Environment Agency. Anyone who buys litter products should look for the “Blue Angel” environmental label, as it does not contain any salts. And if you want to remain completely environmentally friendly, you have to grab the snow shovel as early as possible. Sources: Develey, Federal Environment Agency, BUND Nature Conservation

City to try out new sidewalk machines in a collective push to reduce road salt use - Capital Current

The City of Ottawa will try out machines known as sidewalk controllers this winter in a pilot project to allow crews to more accurately apply and monitor the amount of road salt they apply.

Research by the Ottawa Riverkeeper has highlighted the ecological damage de-icing salt (sodium chloride) does to waterways. Since 2020, significantly higher chloride levels have been measured in urban waterways than in rural. Chloride is harmful to freshwater organisms. Much of the winter salt used on city streets, sidewalks and paths ends up in rivers and lakes.

The city said the machines under consideration are the Kugelmann Winterdienst, Bosch Rexroth 620, Epoke TPS Combi and the Parker Hydraulic.

“Heavy-handed road salt application is a serious issue in most urban zones, and its use has made some freshwater streams and waterways as saline as ocean environments,” said Michelle Woodhouse, water program manager at Environmental Defence in an email.

In Ottawa, city and contracted crews treat all sidewalks. Crews apply grit mixed with salt to the sidewalk network and on residential roads, Christopher Paquette, program manager for the city’s operational research and project unit, said in a statement to Capital Current.

Salemi said new rules could also legally protect small businesses looking to cut their use of salt for the environment. Keeping customers safe remains a central concern for these entrepreneurs.

“At the end of the day, what we’re trying to do is put in [protective] standards for snow and ice management, and that could apply to those small businesses and shop owners that have to deal with their own snow clearing for their storefronts,” Salemi said.

Salemi said even if businesses hire outside snow management contractors, they are responsible for keeping their entries free of snow and ice.

Shovelling salt

Luca De Marinis, an assistant manager at Knifewear Ottawa in the Glebe, says staff shovel and apply salt to the store’s front step.

“We just want to make sure that we can get in and out of the store and customers can get in and out of the store without falling over,” De Marinis said.

Cory Hackett, the owner of Top of the World skateboard shop, said instead of using salt, staff use skateboard grip tape on the part of the shop’s entrance exposed to snow to prevent slipping.

However, Hackett said a significant accumulation of salt still ends up in his shop from the cobblestone sidewalk on which it has been applied by city or contract crews.

“We’re constantly having to mop the floors to lift the salt off of it,” he said.

Jackie Morphy, the owner of All Eco near Lansdowne, said staff use a salt-free de-icer on her store’s front step and rely on mats to prevent customers from slipping. She, too, said salt being tracked in from the sidewalk is a problem.

“I don’t like salt,” Morphy said.

Rock salt is the product most widely available to consumers. Alternative de-icers tend to be more expensive and some have downsides, said Brocklehurst in a statement.

William van Geest, the living city program coordinator at Ecology Ottawa, who encountered an excess amount of sidewalk salt on the Laurier Bikeway last winter, thinks greater education on salt usage from the City of Ottawa could be helpful.

“I know other organizations like the … Riverkeeper do fantastic work that includes educating people on this, but I think it’s in everyone’s interest … to handle winter maintenance correctly,” van Geest said. “I don’t see why it would be unreasonable to expect that from the city.”

Sault Ste. Marie’s plan to make road salt stickier - Sault Ste. Marie News (sootoday.com)

All across Canada, you'll find former Saultites who heap praise on their hometown's ability to clean up after winter storms.

"I used Sault Ste. Marie as an example," says Kerry Diotte, who moved to Alberta four decades ago and laid the foundation for a career in municipal and federal politics by writing newspaper columns describing the awesome snow and ice control back in the Sault.

"I constantly said, places like Sault Ste. Marie and other places I knew in Ontario were far, far superior in terms of getting it done quickly, moving a lot of snow, clearing snow from sidewalks," said Diotte, who's now seeking the Conservative nod to pursue a third term of office representing the federal riding of Edmonton Griesbach.

"Unfortunately, western Canada has really fallen behind in terms of in terms of matching places like Sault Ste. Marie and other municipalities in Ontario," he told SooToday on Wednesday.

Last week, Sault Ste. Marie city council agreed to look into changing the way we deal with big snowstorms, and to seek help from western Canada construction giant Ledcor Group.

Born 75 years ago in Leduc, Alta, Ledcor is now an international company based at headquarters in Vancouver and San Diego.

It has 10,000 employees working out of 20 office locations serving the civil and infrastructure, oil and gas, pipeline, building, mining, power, and telecommunications sectors. 

In recent years, the company has been winning awards for its work in mitigating the risk of salt from its highway maintenance operations contaminating vegetation and ground water

This year Ledcor won a contract with Ontario's transportation ministry to maintain highways in the Sault Ste. Marie area.

Last Monday, city councillors directed that Ledcor be approached to explore the possibility of a pilot project using the company's technology for pre-wetting road salt and sand just before those materials are applied to a road surface.

Pre-wetting has been used in road maintenance since the 1960s.

The idea is to spray rock salt or sand with a liquid de-icing agent (usually salt brine).

Once wet, salt becomes stickier, less likely to bounce off the road or be knocked off by passing traffic.

This allows up to 30 per cent less salt to be used, lowering material cost and reducing environmental impact.

Pre-wetting salt allows ice melting to start earlier, breaking the ice-road bond.

There's also better salt penetration into the ice and snow pack.

Ledcor has recently been upgrading its highway maintenance yards to prevent salt from contaminating sensitive areas including ditches and groundwater.

Mitigation measures have included:

• altering traffic flow to isolate contaminated areas
• changing salt loading and handling procedures
• confining contaminated snow within storage tanks or containment ponds
• paving areas at risk of contamination to make the ground impermeable to salt
• grading the ground with an inward slope to keep contaminated water within the yard
• capturing contaminated water with a catch basin and sump system with above-ground storage
• recirculating contaminated water to reduce off-site disposal and produce salt brine in-house as opposed to buying it 

If Sault Ste. Marie decides to adopt pre-wetting methods, it won't happen immediately.

Among other things, the city must order new salt/sand trucks with pre-wetting capacity.

Also at last week's city council meeting, Ward 4 Coun. Marchy Bruni pushed his fellow councillors to send city equipment onto the end of private driveways to clear the hard, heavy ice that city scrapers deposit there once or twice a year.

Bruni didn't get his way.

There might have been a time when doing that made sense, said Larry Girardi, the city's deputy chief administrative officer in charge of public works and engineering services.

But not now.

"Years back, people had a driveway," Girardi said.

"It was a gravel driveway. They may have had asphalt in the driveway.

"Now we have interlocking bricks. Now we have all these fancy different stamped concrete, and we're going in with heavy equipment and doing damage.

"This is costing the city a lot of time and a lot of money. So when we have to go back, certainly the councillor will get the call.

"We will end up back at the site and there'll be scrape marks from the metal bucket that was in the driveway. And then there's all those complaints for trying to fix that up and it goes on and on."

Councillors rejected Bruni's suggestion, but voted to pursue pre-wetted, sticky salt.

Changing winter weather in P.E.I. may lead to increases in road salt run-off (thespec.com)

CHARLOTTETOWN, P.E.I. — Changing weather patterns may lead to increased run-off and road salt usage during the winter months.

UPEI biomedical sciences and biology professor Michael Van den Heuvel told SaltWire on Nov. 16 that while there is some concern, there is little research being conducted into run-off of road salt.

“Everything with regards to the impacts on P.E.I. is entirely hypothetical,” Van den Heuvel said.

Van den Heuvel said he has yet to come across individuals measuring or studying road salt as an environmental issue in P.E.I. but has seen it done in other areas.

“Nobody has said, ‘Look at all this bad stuff happening due to salt’ on P.E.I. because there’s nothing visually obvious,” Van Den Heuvel said.

Szwarc stated that more than 4,500 kilometres of roadways are plowed during the winter across the province, with approximately 500 km serviced with salt, primarily busy and major roadways.

A sand mixture including a small portion of salt is spread on the remaining 4,000 km of less busy roadways, intended to help with vehicle traction while not damaging the asphalt.

“Salt is used for snow and ice control. For the main highways the goal is to get down to bare asphalt,” Szwarc said.

Approximately 70 per cent of winter road clearing across the province is done by contractors, but those major highways cleared by highway maintenance are monitored and managed around the clock.

“We may look after less, but there is just as much or more gear needed to deal with the weather conditions,” Szwarc said.

The salt and sand used on the Island is transported here throughout the winter, continuously refilling silos across the province.

The amount of salt and sand used in P.E.I. during the winter varies from year to year and is dependent on factors such as temperature fluctuations and the number of storms.

The City of Charlottetown avoids unnecessarily salting of sidewalks and pathways during the winter months, only salting after a freezing rain event or during quick-cooling weather events when ice is most prevalent.

"Using too much salt isn’t effective, you need to use the right amount of material,” Szwarc said.

Salt used on roads is only effective for melting salt when temperatures are under -6 C, but within this temperature zone weather patterns are also subject to change.

Did you know?

The Charlottetown police recommend safe driving habits as P.E.I. prepares for winter driving:

Have winter tires on your vehicle as well as a snow brush/scraper in your vehicle. Clear all windows, lights, mirrors and the top of your car from snow and/or frost before driving. Slow down and adjust driving for road conditions. Leave room between your vehicle and the vehicle in front of you as stopping can take longer on ice/snow-covered roads. Pay attention while driving and make sure you are not distracted.

During winter storms, road salt that does not dissolve can be pushed off the road by snowplows, washed away in the rain and otherwise disturbed.

Van den Heuvel explained that while there has not been any visual evidence of the environmental impacts of road salt, the Island remains an ideal location for research on this subject.

“The density of roads is higher than any other province in Canada, so if you're going to have salt effects we would certainly be somewhere where you might expect to see that,” Van den Heuvel said.

More research is required to better understand the impact of salt and sand on the environment, weighing the environmental hazards of both materials while continuing to provide safety for motor vehicles.

Reducing road salt use 'not something that can wait' as Ontario lakes see oxygen depletion, researcher says | CBC News

The move to reduce the amount of road salt during the winter months can't wait because Ontario's groundwater and lakes are showing "very rapid salinization," researchers at the University of Waterloo say.

"We actually use a lot of of salt, and salt is a very effective way to keep roads, sidewalks and parking lots free of ice, and that, of course, is important in terms of ensuring the safety of road users and pedestrians," said Philippe Van Cappellen, a professor and researcher at the school, as well as the Canada Excellence Research Chair Laureate in Ecohydrology

"But I think it's also very, very important to be aware that there's a downside to the use of salt," he added.

He said previous research has shown groundwater and lakes in Ontario are becoming saltier.

Most recently, Van Cappellen was part of a research group that looked specifically at Lake Wilcox in Richmond Hill. It examined the salinity — the amount of dissolved salt in a body of water — and how it has increased dramatically in the lake over the last nearly 30 years. 

As part of the study, which was published this month in the journal Science of The Total Environment, the researchers looked at water chemistry, land use and climate data going back to 1996 along with recent testing of the water.

As the amount of salt in the lake increased, Van Cappellen said, they also saw a depletion of oxygen.

As salinity increases, so does the density of the water, and that makes it more difficult for the lake to "mix," he explained.

"The mixing of the lake is what really takes the oxygen from the top of the lake — the part that's in contact with the atmosphere and gets its oxygen from — and to bring that oxygen down into the deeper parts of the lake," Van Cappellen said.

People, animals and plants need oxygen to survive, and when oxygen is depleted, the only organisms that can survive are microorganisms, Van Cappellen said.

"These microorganisms often produce noxious byproducts." He said that can create the rotten egg smell that is in the air when hydrogen sulfide is produced by certain bacteria in the absence of oxygen.

"That also limits the amount of the lake that … is habitable for higher organisms such as fish," he said.

"It's really something that's really affecting the water quality, it's really affecting the biodiversity of the lake."

Van Cappellen said he wants local municipalities to talk about their road salt use, setting targets such as reducing its use by 25 per cent in the next five years.

"It's not something that can wait for another 10 years or 20," he said. "I think it should be an ongoing process."

'Right amount in the right area'

Some municipalities have experimented with different ways of deicing roads, sidewalks and parking lots. They include Calgary and Winnipeg, which in the past have used a mixture that includes beet juice, and places in Wisconsin have experimented with cheese brine.

David Pressey, the Region of Waterloo's manager of transportation operations, said the municipality has been aware of concerns about the use of road salt and has actively worked to decrease its use.

"We have to ensure that the users of the road are able to get from home to the grocery store and back without incident. So that is our first and foremost concern. The environment is right there," he said.

"We work with our environmental services team routinely to ensure that we are applying the right amount in the right area and ensuring that we are staying away from those sensitive areas."

The region will lay down a brine solution when it learns a storm is coming, helping reduce the amount of rock salt spread during plowing.

"Ten years ago, and even 15, 20 years ago, maybe the environment wasn't first and foremost, maybe the products used were different than today," he said. 

"We're continually looking and researching for enhanced materials to use that are more effective and more environmentally friendly."

Salts used on roads and sidewalks in the winter affecting fresh water sources: U of G prof | CityNews Kitchener

With winter on the way this weekend, a professor from the University of Guelph is warning of the dangers of over salting.

Dr. Ryan Prosser, a professor in ecotoxicology at the school of environmental sciences, said the water flowing from roads and sidewalks are making lakes, rivers and streams more salty. This is due to the water not being as diluted and affecting wildlife that has evolved and live in fresh water sources, such as fresh water mussels.

One of the big drivers of using more salt is due to the rising population of cities like Kitchener and Waterloo.

“I am concerned about the impact that it is going to have on our fresh water ecosystems,” said Prosser. “It’s going to become harder with more people and greater road density and more road salt.”

The goal would be to use less salt, said Prosser. But this can come with its own risks due to liability for not salting driveways and roads.

“Ideally, we would want to see individuals or commercial properties to use salt sparingly. But on their side, they’re concerned about the liability aspect,” said Prosser. It’s still trying to find a happy medium between the two.”

Some alternatives have been suggested, such as a beet juice-based brine. However, Prosser said this is still toxic to ecosystems because of the higher levels of potassium.

Road salt—a scientific, environmental, and labour issue with a legislative solution - The Queen's Journal (queensjournal.ca)

Dropping temperatures mean students across Kingston are waking up to ice-covered sidewalks as a welcome to Canada’s natural slip ’n slide.

Along with the ice comes one white substance we can’t get enough of: road salt. Unfortunately, the use of salt not only impacts the environment, but those whose job it is to spread it.

“The salt issue is multifaceted. It’s people’s behavior and expectations. It’s how we’re dealing with liability and litigation. And then the ecology and toxicology part,” said Shelley Arnott, Queen’s biology professor, in an interview with The Journal.

Canada uses five million tons of road salt every year in an effort to save lives and avoid injuries caused by hazardous winter conditions. At Queen’s, road salt is often spread over stairs, walkways, and parking lots, keeping people from slipping while damaging the aquatic ecosystem closest to us, Lake Ontario.

Arnott remembers when people used to say, “the solution to pollution is dilution.” The idea was that society didn’t need a solution to road salt pollution, because it would wash into large water ways, diluted and safe. As a long-time researcher of the impact of salt on aquatic ecosystems, Arnott can confirm this isn’t the case.

“It was just mounting evidence that sodium chloride, or road salt, was way more toxic than we thought,” Arnott said.

Researchers like Arnott use chloride, an ion formed when salts are dissolved in water, to measure the salt concentrations in lakes near urban areas.  When Arnott began her research, she focused on its impact on smaller organisms, such as Daphnia—water fleas that feast on algae and are an integral part of lake ecosystems.

“We were seeing effects, reduced reproduction and increased mortality, at concentrations as low as five to 40 milligrams of chloride per litre,” Arnott said. “That was pretty shocking because our water quality guidelines suggest that 120 milligrams of chloride per litre should be protecting most aquatic species.”

Daphnia are highly sensitive to chloride, making them an important indicator of salt concentration in lakes. As Daphnia die, the algae they feed on will bloom and fish can perish without water fleas as a food source.

Though Lake Ontario is one of the largest bodies of water in North America, Queen’s and Kingston’s  habitual use of road salt will still have an impact, especially on organisms that live near the shore, according to Arnott.

As a long-time member of the Queen’s community, Arnott is disheartened when road salt is overused around campus. Limiting the use of salt is one way to reduce its environmental impact.

Unfortunately, oversalting isn’t a one-dimensional issue. 

Snow and ice management contractors are pressured to oversalt roads, sidewalks, and parking lots so the businesses and municipalities they work for won’t be sued.

Landscape Ontario, a horticultural trades association, has been calling for the legal protection of contractors who spread road salt within communities. The association’s Snow and Ice Management Sector group is working to reduce salt’s environmental impact.  

Aside from the environmental threat, the current legal landscape puts snow and ice contractors at a disadvantage.

The high risk of slip and fall claims increases insurance costs related to ice management. As a result, contractors are slowly abandoning businesses, according to Landscape Ontario. This is leaving municipalities without people willing to spread salt. 

“Snow and ice management contractors are essential, frontline workers. Without them, it’s impossible for Ontarians to get to work and school—and even more critically, they allow emergency services teams to reach people in need,” said Joe Salemi, executive director of Landscape Ontario, in a statement to The Journal.

As changing weather patterns cause unpredictable freeze and thaw cycles, Landscape Ontario says oversalting is becoming more common. 

“If the workers feel like they could get sued, then they’re going to put as much as they can to ensure they don’t,” Arnott said. 

A lobby day at Queen’s Park on Oct. 24 brought together ice management contractors and MPPs, as well as Doug Ford, to discuss the environmental and labor issues of road salt use in Ontario. 

Landscape Ontario hopes the provincial government will reform the liability surrounding slip and fall claims, and establish a regulatory framework for ice management to help prevent oversalting.

“We were introduced in the House by MPP Parm Gill, minister of red tape reduction, and Andrea Khanjin, minister of the environment, conservation, and parks, [who are] committed to championing the cause in [provincial legislature],” Salemi said.

Though it may be a long way from legal changes of contractor liability, there are some easier solutions.

Instead of salting the roads, some municipalities in Canada such as Kingston are using brine—a mixture of salt and water that uses less salt.

Road salt only works when there’s a little bit of liquid water on the ground already—without water, the salt has no effect. The salt ions dissociate in surface water, lowering its freezing temperature and preventing the lattice structure of ice from forming on pavement. Using brine guarantees there’s water available for the salt to dissociate, ensuring ice doesn’t form.

“It’s not taking away the toxicity it’s just reducing how much you’re using,” Arnott said.

Though there are many eco-alternatives available, Arnott cautions against believing everything on a label. 

“I can’t use salt when I know how damaging it is. So, I get out and shovel,” Arnott said.

Why Kelowna doesn’t use beet brine on winter roads - Kelowna News - Castanet.net

A year ago this week, Kelowna drivers were slipping and sliding through an early snowfall.

So far, the forecast indicates only rain this week for the city, although Big White got a large dump of 15 centimetres Monday night and into Tuesday morning. As winter looms, the City of Kelowna is gearing up for winter road maintenance.

The city’s 2023 Snow and Ice budget is $2.475 million. Year-to-date, $1.46 million has been spent, between January and March. That leaves approximately $1 million in the kitty to plow, sand and de-ice roads from now until the end of December.

One thing you won’t see on the roads of Kelowna is beet brine. The naturally-sourced de-icing material has been used in a number of locations in recent years, most notably, in Calgary. It was also tried in a pilot project on the Coquihalla Highway starting in 2016/17.

“The biggest drawback to using beet juice is the same reason as to why disposal units in the sink, garburators, have been banned. Because we’re basically putting food out on the road,” explains City of Kelowna Infrastructure Operations department manager Geert Bos.

He says that raises environmental concerns because, as a food product, it will place a biological oxygen demand on waterways it runs into, making it more difficult for fish and other aquatic species to breathe.

“Even though it sounds counter-productive, that it’s environmentally friendly because it’s a waste food product, it’s actually quite damaging to the environment if it makes it into the open waterways.”

He says another drawback of beet juice is that it’s like molasses. It becomes tacky and can be dragged into homes and businesses, creating a sticky mess.

Instead, the city uses liquid calcium chloride, typically as a defense strategy before hard freeze or snow events. “It’s basically a calcium-based salt that is diluted. It’s a liquid that we disperse over the roads,” adds Bos, who notes it is essentially a chemical compound.

The city also applies road salt and sand to help drivers get traction and to melt compact snow down to “bare” pavement.

Last winter’s early snowfall, which came mostly in November and December, pushed Kelowna’s 2022 snow removal costs $1.17 million above the $2.2 million budget.

Road Salt Type Crucial for Winter Plant Health | Mirage News

Increased salinity in soils is a global problem caused for example by ions leaching into soils from ice-melting salts used on roads in winter or from seawater seepage in coastal areas. Salinisation of farmland affects more than one and a half billion people worldwide. Researchers at Eötvös Loránd University (ELTE) investigated how high salt concentrations affect the development of wheat seedlings, which germinate deep in the soil, and what can be done to reduce the damage caused by salinisation.

Increased salinity in soils, i.e., salinisation, is a global problem in agriculture, but also affects local crop production in gardens and in farmlands close to roads where large amounts of salts are used in winter as ice-melting agents, and in coastal areas where seawater seepage may occur. In nature, the leaves of seedlings growing in the dark deep in saline soils can be directly exposed to different ions in the soil, which can cause plant stress and ultimately plant death.

Researchers from Eötvös Loránd University have shown that greening, that is, the biosynthesis of the green pigment, chlorophyll, and the development of photosynthetically active plastids, called chloroplasts, are inhibited in wheat leaves grown in the dark and then directly exposed to high salt concentrations. This can eventually lead to the death of the seedlings.

Katalin Solymosi and her research group have used a very simple and reproducible method to easily identify which salts and in what concentrations have the most harmful effects on the greening of plants germinating in soil. Sodium (Na+) was found to have the most negative effect, while potassium (K+) salts (e.g., in the form of wood ash, traditionally often used for such purposes) and calcium chloride (CaCl2) can be considered as more environmentally friendly ice-melting compounds.

A GLOBAL PROBLEM

Increased soil salinity affects an estimated 833 million hectares of land worldwide. Unfortunately, due to inappropriate agricultural practices, this area is constantly increasing. The concentration of salts and the available water is constantly changing in the soil depending on several factors, including the quality and quantity of rainfall, external temperature, and evaporation.

"Many researchers have been investigating for a long time how high soil salinity inhibits the germination of most economically important crops and reduces their yields. However,

no studies are available about how saline soils affect the leaves of plant seedling developing from seeds sown deep into the soil according to agricultural planting protocols of many crops.

This is even more surprising as salinisation of croplands affects about one and a half billion people worldwide," explains Katalin Solymosi, assistant professor at Eötvös Loránd University and lead researcher of the study.

THE INVISIBLE DEATH OF WHEAT

Depending on the soil type and the used wheat cultivar, wheat is usually sown 5-10 cm deep into the soil. Thus, the germinating wheat seedlings first develop in the soil in complete darkness. Due to the lack of sunlight, they do not produce the green pigment chlorophyll, which is characteristic of plants, and are therefore yellowish in colour. Without chlorophyll, the photosynthetic apparatus cannot develop, and a specific plastid type, the so-called etioplast develops in the leaves of these seedlings. When the leaves of developing plants reach the soil surface and are gradually exposed to light, chlorophyll is synthesized in them, the plants turn green and the etioplasts in them are transformed into green plastids, called chloroplasts. Chloroplasts are photosynthetically active and help the plant to produce sugars and thus energy for survival.

Without the switch to self-sustaining photosynthesis, seedlings will eventually use up the nutrients stored in their seeds and die.

"In this context, it is particularly surprising that no study has so far investigated in detail how high salt concentrations affect the greening of wheat seedlings, even though it is obvious that the leaves of plants germinating in soil are directly exposed to soil salinity" - says Adél Sóti, PhD student at Eötvös Loránd University, first author of the study published in the journal Planta. - "We found a simple method to investigate how salt affects the greening of plants. After 11 days of germination in complete darkness, for example in a closed box, leaf pieces of seedlings were first exposed to different concentrations of salt for 1.5 hours as a pretreatment and then illuminated in relatively low light to green them. Greening, that is the appearance or absence of green colour after 16 hours of illumination, is readily visible to the eye and indicates the extent to which the saline solution was detrimental to the process."

SALT STRESS AND WATER SHORTAGE

In fact, it is surprising that even half the salt concentration of seawater (i.e., about 300 mM NaCl) does not completely inhibit wheat greening but slows down the transformation of etioplasts into chloroplasts. However, at relatively high salt concentrations (e.g., 600 mM NaCl), equal to the salinity of seawater, greening is completely inhibited and specific structural changes, such as the swelling of the inner membranes of the etioplasts, are observed.

High concentrations of saline solutions have negative effects on plants through at least two main mechanisms:

because they are rich in dissolved ions, they can hinder water uptake and thus cause so-called osmotic stress, and the various salt ions can have a direct toxic effect on cells after uptake and thus interference with their metabolism.

Within the framework of the ERASMUS+ staff mobility programme, Hungarian researchers, in collaboration with Beata Mysliwa-Kurdziel from the Jagellonian University in Krakow, conducted systematic studies to test whether the osmotic stress caused by the applied saline solutions significantly contributed to the observed inhibition of greening. For these studies, a non-ionic compound, polyethylene glycol, was used at the same osmolarity as the saline solutions to mimic the osmotic stress caused by the different saline solutions.

LESS SODIUM, HIGHER YIELD

"With electron microscopic investigations we showed that the large and abnormal swelling of the water-containing inner space (called lumen) of the etioplast inner membranes did not occur during the application of only osmotic stress and was only observed in samples treated with high Na+ concentrations. Our comparative analyses showed that high concentrations (600 mM) of KCl, KNO3 or 300 mM CaCl2 also slowed down the greening, but did not induce such marked ultrastructural changes" – summarized Katalin Solymosi the main conclusions of the study.

These results may reinforce the collective wisdom of people to use, for example,

wood ash enriched in potassium salts (K+) instead of sodium salts for de-icing snowy roads in winter.

Similarly, CaCl2 is considered a more environment friendly ice-melting and anti-skid agent. At high concentrations, however, neither salts have a positive effect on the greening of seedlings, which is something to bear in mind during winter snowfalls if you want to have a beautiful garden with lots of green plants next spring.

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West Berkshire winter road gritting service officially begins - BBC News

A council has officially begun winter gritting on its roads, with thousands of tonnes of salt ready for use.

West Berkshire Council is responsible for protecting 529km (328.7 miles) of main roads and 259km (161 miles) of minor roads from ice and snow.

It has 2,200 tonnes of salt available, 1,200 tonnes of which is kept at Chieveley Depot.

During last year's winter period, between October and March, 441 roads were gritted in West Berkshire.

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The council has a statutory duty to ensure safe passage along roads in its district.

It uses information from roadside sensors and detailed site-specific forecasts issued by forecaster providers when deciding whether to send gritters out.

It also salts specified sections of the footway network during prolonged hazardous conditions and when snow is forecast, though remote cycle paths are not treated.

A winter services duty officer is available 24 hours a day.

There are 30 available salt bins owned and maintained by the council, with 446 others owned and maintained by the parish and town councils.

The treatment of the M4 motorway and the A34 trunk road is the responsibility of National Highways.