For decades, peat has been the backbone of modern plant production. However, with increasing focus on climate impact, biodiversity, and sustainable resource management, the entire industry is facing a necessary transition. The question is no longer whether we need to reduce our reliance on peat—the question is how we do it.

Today, significant research efforts are being directed toward developing new and more sustainable growing media. Coconut coir, wood fiber, bark-based products, and a range of other alternatives are being developed and tested around the world. These initiatives are important and will undoubtedly contribute to a more sustainable future for horticulture.

However, during the discussion in Amsterdam, SoilSteam highlighted a perspective that often receives too little attention:

The most sustainable substrate is the substrate that has already been produced.

Why Replace a Substrate That Can Still Be Used?

Every year, millions of cubic meters of growing media are transported to greenhouse operations around the world. After a single growing season, much of this material is replaced with new substrate—even though it often retains excellent physical properties.

For several years, SoilSteam has focused on one key question:

Can substrate be treated and reused without compromising yield or crop quality?

The answer is becoming increasingly clear.

Documented Results from Leading Research Institutions

In collaboration with organizations such as Proefcentrum Hoogstraten in Belgium, SoilSteam has conducted extensive trials to document the effects of steam treatment and substrate reuse.

The results show that strawberries grown in steam-treated, reused substrate achieve yields comparable to those grown in new substrate.

This is no longer limited to small-scale research trials.

Several of Belgium’s largest strawberry growers are now conducting full-scale commercial trials, where entire greenhouses are grown on steam-treated and reused substrate and directly compared with greenhouses using new substrate.

The results so far are highly encouraging:

The yields are the same.

We are seeing similar results from ongoing full-scale trials in tomato and pepper production.

The Road Ahead: More Research and More Documentation

While the results are very promising, this is only the beginning.

SoilSteam will continue collaborating with some of the world’s leading researchers and research institutions to document the effects of substrate reuse across more crops, more substrate types, and a wider range of growing conditions.

Our objective is not simply to prove that reuse is possible.

Our objective is to demonstrate that substrate reuse is:

• Sustainable
• Safe
• Agronomically sound
• Economically profitable

One of the Greatest Economic Opportunities in Modern Horticulture

For growers, this is not only about sustainability.

It is also about economics.

By steam-treating and reusing their own substrate, growers can reduce substrate-related costs by up to 80% compared with purchasing new substrate year after year.

At the same time, growers gain:

• Full control of their own substrate
• Predictable costs
• Reduced exposure to rising substrate prices
• Lower transportation costs
• Less dependence on global supply chains
• Improved biosecurity and greater control over substrate hygiene

Growers no longer need to worry about delivery delays, increasing freight costs, or whether incoming substrate is as clean and reliable as expected.

A Powerful Climate Measure

The production and transportation of new substrate represent a significant share of the carbon footprint associated with modern horticulture.

By reusing substrate multiple times, growers can dramatically reduce the need for new raw materials while eliminating a substantial portion of the CO₂ emissions linked to substrate procurement.

For many producers, substrate reuse may be one of the most effective climate actions available—without compromising productivity or profitability.

The Future of Substrates Is Circular

The discussion at GreenTech clearly demonstrated that the industry is entering a period of significant change.

New growing media will undoubtedly play an important role in the future.

However, if our industry is to reduce resource consumption, costs, and climate impact on a meaningful scale, we must also ask a fundamental question:

Why use a substrate once when it can be used multiple times?

At SoilSteam, we believe the future of horticulture is not only about finding new substrates.

It is about creating a circular system where valuable resources are reused again and again—delivering the same yields, lower costs, and a dramatically reduced environmental footprint.

That is what we mean when we say that the future of substrates is circular.

You can use our calculator to estimate how much money and CO₂ emissions you could save by steam-treating and reusing your substrate instead of purchasing new material every season: https://substratecalc.com/

The post The Future of Substrates Is Not Just About New Materials – It’s About Reuse appeared first on SoilSteam International.

Incorrect handling of soil can lead to project delays, increased costs, regulatory non-compliance and long-term environmental damage.

The good news is that much of this risk can be eliminated before the first shovel hits the ground – if the right decisions are made early.

Below are the key steps every project should follow.

1. Identify invasive species before the design phase begins

The first – and most important – step is to understand what is present on site.

• Carry out an early ecological / environmental survey
• Identify:
  • invasive plant species
  • areas at risk of spread
  • existing soil that may be contaminated with seeds, roots or plant material

👉 Projects that overlook this in the early phase often experience:

• sudden stoppages on site
• costly emergency measures (often dig & dump)

2. Understand that soil is biological material – not just bulk mass

Soil containing invasive species is not inert waste – it is a biological risk material.

Common mistakes include:

• temporary storage without containment
• transporting soil between multiple locations
• reusing soil without treatment

The result can be unintentional spread both within and beyond the project area, often not discovered until months or even years later.

3. Plan soil management as part of the overall project logistics

Soil should be treated as a dedicated workstream, just like concrete, steel or logistics.

Well-managed projects:

• clearly define which soils are “clean” and which are “risk material”
• establish clear procedures for:
  • excavation
  • temporary storage
  • treatment or final use
• avoid unnecessary transport and re-handling

👉 This leads to better control, lower costs and fewer surprises.

4. Avoid “dig & dump” as the default solution

Excavating soil and sending it to landfill has long been the standard response to invasive species. In practice, this approach is often:

• expensive
• logistics-intensive
• dependent on limited landfill capacity
• environmentally unsustainable

Across many parts of Europe, millions of tonnes of biologically contaminated soil are handled this way every year – despite the soil itself often being of high quality.

5. Consider treating soil on or near the construction site

Modern projects increasingly view soil treatment as an alternative to landfill.

Key benefits include:

• reduced transport and disposal costs
• elimination of spread risk
• enabling safe reuse of soil within the project
• improved documentation and control

For many projects, this can be the difference between a reactive and a proactive environmental approach.

6. Document – for authorities, clients and future liability

Regardless of the method used, documentation is critical:

• What was identified?
• How was the soil handled?
• How was biological risk eliminated?

This protects:

• the contractor
• the client
• the developer

— both legally and financially.

Final thoughts: Start right to avoid costly consequences later

The spread of invasive species is rarely the result of bad intent – but often of insufficient planning in the early stages.

The most successful projects:

• take biological risk seriously
• plan soil management strategically
• choose solutions that reduce both environmental impact and cost

At SoilSteam, we work with contractors and developers who want to:

• eliminate biological risk in soil
• reduce reliance on landfill
• enable safe reuse of soil

👉 Engage early in the project phase – that’s where the best solutions are created.

The post How to Prevent the Spread of Invasive Species When Starting a Construction Project appeared first on SoilSteam International.

Why Hand Pulling Is Ineffective:

1. Deep Root Structure:
   Japanese knotweed has a powerful rhizome network (underground stems) that can grow up to 3 meters deep and spread 7 meters from the parent plant. Removing only the visible parts will result in rapid regrowth from the remaining roots.
2. Spread Through Small Root Fragments:
   Even tiny root fragments (as small as 1 cm) can develop into new plants. Hand pulling can inadvertently lead to further spread if root pieces are left in the soil.
3. Rapid Regrowth:
   The plant grows quickly and can return with renewed vigor after pulling, especially if the roots are not completely removed.

Effective Control Methods:

1. Digging:
   Dig out as much of the root system as possible, being extremely careful to remove all root fragments. This process is non-sustainable and often requires repetition over several seasons.
2. Covering:
   Cover the area with light-blocking materials (e.g., thick tarps or geotextile fabric) for several years. This deprives the plant of sunlight, gradually weakening it over time. Ir might be effective, but VERY time-consuming.
3. Steam Treatment:
   For larger areas, steam treatment can be an effective method. Technologies like SoilSteam can eliminate both roots and seeds in the soil using hot steam. This is quick and effective and the soil might be used after. You need large equipment, so this method is for professional use.
4. Continuous Cutting:
   Frequent cutting (every 2–3 weeks) over several years can gradually weaken the plant. Cut material must be disposed of properly to prevent further spread. This is time-consuming and requires discipline.
5. Chemical Treatment:
   Contact a specialist with the proper authorization to apply herbicides. Such treatments typically require multiple applications per season and ongoing follow-up for several years. Due to their potential environmental impact, many people prefer to avoid chemical herbicides in private gardens. Professional help is needed to ensure correct chemical treatment.

When to Seek Professional Help:

Regardless of the method chosen, it is advisable to consult professional help. SoilSteam offers an immediate solution with just one treatment. However, the challenge is that these are large, complex machines, making them economically and logistically impractical for small-scale areas.

All other methods will require continuous monitoring and repeated treatments over several years to achieve lasting results.

The post Effective ways of Removing Japanese Knotweed (Reynoutria japonica) appeared first on SoilSteam International.

Much of the food on store shelves today is produced in substrate. The substrate can be based on various raw materials, with peat and crushed coconut husks being the most commonly used. The problem is that these substrates are usually only used once. This is because fungi and other pests can establish themselves in the substrate during cultivation, potentially ruining future crops. Sterilization and reuse of substrate will be one of the most important environmental measures for greenhouse production worldwide:

1. Sustainability, Stability and Environmental Considerations

• Reduced peat extraction: Peat is a non-renewable resource that takes thousands of years to form. Large amounts of peat are used in greenhouse production, but its extraction releases CO₂, contributing to climate change. Reusing peat can drastically reduce the demand for new peat.
• Less waste: Used substrate is often discarded or treated as waste. If it is sterilized and reused, the amount of waste can be significantly reduced.
• Compliance with future environmental regulations: Several countries are considering restrictions on peat use in agriculture and horticulture (e.g., the UK plans to phase out peat in gardening products). Reuse can be part of the solution to meet new regulations.
• Less transportation and freshwater use: Coco coir is produced in distant regions and must be transported over long distances. In turbulent times, international transport becomes complicated and often costly. Additionally, large amounts of freshwater are used during production, freshwater that could have been used by local populations.

2. Economic Benefits for Growers

• Cost savings: Buying a new substrate is expensive. If growers can use the same substrate multiple times without losing quality, they can save significant amounts of money. This could also benefit consumers through lower prices.
• Production stability: Importing substrate is vulnerable to supply chain issues. Reusing existing substrates gives growers greater stability and predictability.

3. Proven Effectiveness

• Steam treatment eliminates diseases: Steam sterilization is a well-known method for eliminating fungi, bacteria, and nematodes from soil and substrate. Studies show that plants grown in steam-treated substrates often have the same growth quality as those grown in new substrates.

The reuse of substrate will be an important step toward sustainable agriculture. It will help reduce greenhouse gas emissions, lower costs for growers, and ensure compliance with stricter environmental regulations.

SoilSteam is working with Europe’s leading research center for greenhouse production, Proefcentrum Hoogstraten, to document that steam treatment of substrate is a future-oriented solution. The first machines adapted for substrate recycling will be ready for delivery in 2025.

The post 3 Reasons Why you should Reuse Peat and Coco Coir (Substrate) in Greenhouse Production appeared first on SoilSteam International.

The reason peat and coconut fiber (hereafter referred to as substrate) have become so popular is that they are clean, homogeneous growing media, completely free of fungi and other pests. Substrate is increasingly used for the production of fruits, plants, and vegetables in greenhouses as an alternative to soil. The problem is that after just one season, it can no longer be guaranteed to be clean. Therefore, producers cannot risk reusing the substrate, as this could lead to poor yields risk farmers cannot afford to take. This is, of course, not sustainable. Fortunately, there is a solution.

Innovative Collaboration for Sustainable Production

In collaboration with the research department of one of Europe’s most renowned strawberry regions, Proefcentrum Hoogstraten, SoilSteam has conducted tests to enable the reuse of substrates. Peter Melis, Strawberry researcher at Proefcentrum Hoogstraten, is very optimistic:

— We have a strong focus on sustainability in our production. Nevertheless, it is a fact that much of strawberry production takes place in substrates that are not reused due to disease presence. There are significant environmental issues related to the extraction of peat-based substrates and therefore heat treatment and reuse may be key to more sustainable production. After assisting SoilSteam during testing, I have high hopes that this method can make reuse possible, says Melis.

Promising Tests with SoilSaver 5

Proefcentrum Hoogstraten and SoilSteam have collaborated to steam-treat 10 m³ of substrate that has already been used in strawberry production. After steaming, researchers at Hoogstraten will attempt to grow new strawberries in the heat-treated substrate and compare the results with strawberries grown in fresh and reused substrate. External research shows that steaming of peat might give good results – something we now aim to verify. SoilSteam are ready to start serial production of the machine if the results are good.

Potential for Global Impact

If the results are positive, this could open up entirely new opportunities for sustainable substrate reuse. Oddbjørn Bergem, CEO of SoilSteam, says:

— We have been steaming soil for many years, but it is exciting to gain more experience with this type of substrate. The operation itself went according to plan, and we are fortunate to work with such a dedicated team at Proefcentrum Hoogstraten. Here, we will obtain solid documentation on whether steam-treated substrate performs as well as new substrate. SoilSaver 5 is a custom made machine for the substrate market according to Bergem.

Zero CO₂ Emissions with New Technology

The steaming in Hoogstraten, Belgium, was carried out using the brand-new SoilSaver 5 machine from SoilSteam. This is a 100% electric machine, which means the process is entirely CO₂-free. This makes the technology a sustainable alternative that not only reduces the environmental impact associated with substrate production but also the reuse process itself.

See a short movie of the process here

The post Innovative Project with Great Potential: Reusing Substrates Can Improve the Sustainability of Strawberry Production appeared first on SoilSteam International.

A Step Towards a Greener Future

Traditionally, large amounts of contaminated or biologically compromised soil are deposited, leading to unnecessary resource consumption and environmental strain. Through collaboration with SoilSteam International, a provider of advanced steam technology for soil decontamination, Kinn Municipality is taking an important step to ensure that soil masses are not only cleansed but can also be reused in future projects.

“We are proud to set an example of how construction projects can be carried out in a more environmentally friendly manner. Reusing decontaminated soil reduces the need for extracting virgin materials and minimizes transportation requirements,” says Inge Andre Fosse Ytredal, Construction Manager at Mesta.

Efficient Steam Treatment Yields Clean Results

The process involves excavating the soil, coarse sorting to remove large stones, and temporarily storing it before it passes through a screening plant and SoilSteam’s steam machine. The steam treatment effectively eliminates unwanted seeds, plant diseases, and other biological contaminants without the use of chemicals. This ensures that the soil can be reused without concerns about harming crops.

“Our technology provides an environmentally friendly method for decontaminating soil, and it is inspiring to collaborate with a municipality like Kinn, which recognizes the value of investing in sustainable solutions,” says Hans Kristian Westrum, Sales Manager at SoilSteam International. “Last year, we saw the Norwegian Public Roads Administration (Statens Vegvesen) focus on soil reuse when they chose Dokka Entreprenør to execute a road project in Jevnaker. This led to the recovery of 4,000 tons of soil. Now, we see that both counties and municipalities are becoming interested in this, and it is encouraging for both us and the environment that Kinn Municipality has chosen this sustainable solution,” he says.

Cost-Effective and Environmentally Smart

“Although steam treatment involves a cost, we compared this expense with the alternative of transporting and depositing the soil masses. As a result, steam treatment and reuse turned out to be the more cost-effective solution,” says Jorunn Reisæter, Climate and Environmental Advisor at Kinn Municipality. “Additionally, the significant environmental benefits are difficult to put a price tag on,” she concludes.

The Future of Construction Projects in Norway?

With Kinn Municipality leading the way, this initiative could inspire other municipalities and contractors to rethink soil management. Sustainable solutions like this may soon become the norm rather than the exception in Norway’s construction industry.

The post Kinn Municipality Takes the Lead in Sustainable Construction Practices: First Municipality in Norway to Choose Steam Treatment of Soil with Japanese Knotweed for Reuse. appeared first on SoilSteam International.

Based on this, we at SoilSteam contribute to developing a Norwegian Standard for heat-treated soil. This standard will ensure that buyers of soil can be confident that the soil is heat-treated and therefore free of harmful organisms and weeds. Steamed soil is becoming increasingly popular among landscapers, and here we explain why:

One of the biggest challenges for landscape gardeners is weeds that compete with plants, creating extra costs and additional work. By using steam-treated soil, this problem is largely avoided. It also reduces the need for chemical pesticides. In addition, the use of steam-treated soil leads to more satisfied customers.

Weeds grow quickly and controlling it throughout the season requires regular maintenance, including weeding at least once a month. In a hectic summer season, this can be difficult to achieve in practice, which often results in planting areas that look poorly maintained. By using steam-treated soil, this problem is avoided. The soil will generally remain weed-free without incurring maintenance costs. This makes the slightly higher price of heat-treated soil justifiable, as it results in happier customers and lower long-term maintenance costs.

For landscape gardeners who aim to deliver high-quality results with minimal maintenance and no use of pesticides, steamed soil is the right choice.

What do you think? Will you use steamed soil in your next project? Contact us to learn more about steam-treated soil.

The post Why Landscape Gardeners Choose Steamed Soil for Park and Garden Projects appeared first on SoilSteam International.

Why Steam Treatment?

When soil is moved during construction or agricultural projects, it can carry harmful organisms that spread to new areas. Traditionally, this has led to strict restrictions, including prohibitions on relocating contaminated soil. Now, heat treatment is considered a solution that ensures soil quality while protecting the environment from the spread of unwanted species.

Soil heat treatment involves heating the material to temperatures that kill seeds, plant pests, and microorganisms. This process, which is expected to become part of the Norwegian Standards framework, can potentially revolutionize the handling of problematic soil in Norway.

Picture: Norwegian authoroties have now opened up to recycle biological contaminated soil after heat/steam treatment.

Benefits for the Environment and Society

This initiative represents a win-win situation for both the environment and society:

1. Waste Reduction: Instead of disposing of contaminated soil, it can be cleaned and reused.
2. Preservation of Topsoil: Soil is a valuable resource, and reuse contributes to sustainable resource management.
3. Prevention of Environmental Damage: Heat treatment prevents the spread of harmful species that can threaten biodiversity and agricultural productivity.

The Way Forward

For this method to succeed, collaboration between public agencies, contractors, and technology developers is crucial. The Norwegian Food Safety Authority highlights the importance of planning and thorough mapping before project initiation, as well as the need for permits when moving contaminated soil.

This is encouraging news for stakeholders in construction and agriculture, demonstrating that Norway is taking concrete steps to address future challenges sustainably. Heat treatment of soil could become an example for other countries seeking to combine environmental protection with efficient resource use.

We now look forward to the implementation of a Norwegian Standard for soil heat treatment – a vital step towards a greener future!

The post Norwegian Authorities Opens for Steam Treatment to Enable Sustainable Reuse of Soil appeared first on SoilSteam International.

We want to take this opportunity to extend a special thanks to Statens Vegvesen and Dokka Entreprenør AS – respectively the developer and contractor of a groundbreaking project that represented the world’s first project where soil was steam-treated and reused directly on site. These players are pioneers in sustainable soil management, leading the way for the future. This effort not only represents a significant reduction in environmental impact but also an important step toward more sustainable stewardship of our valuable soil resources.

Bergknapp also deserves recognition. Jakob and his talented team are the only green roof providers using steamed soil in sedum production. By doing so, they ensure minimal weeds in their products, simplify maintenance, and deliver better products with less maintenance.

We look forward to continuing this important work with you in 2025 – a year we hope will bring new exciting projects and new opportunities to make a difference! Our goal for 2025 is for our SoilSavers to recover at least 20,000 tons of soil, equivalent to 1,000 truckloads. To achieve this, more contractors and landscapers need to steam and recover soil containing invasive species rather than sending the material to landfills. Landfilling soil is not sustainable and is often more expensive than steam-treating and reusing it.

Merry Christmas and Happy New Year from all of us at SoilSteam!

The post SoilSaver saved 9000 tons of soil in 2024 – join us in saving more soil in 2025! appeared first on SoilSteam International.

Challenges in Soil Quality
One of the biggest concerns today is the declining quality of arable soil. Globally, around 33% of soil is degraded due to erosion, pollution, salinization, or nutrient depletion. This degradation is mainly caused by unsustainable agricultural practices, heavy use of chemicals and fertilizers, and harmful organisms in the soil. These practices lead to a loss of soil biodiversity and a decline in essential soil organisms that help break down organic matter and cycle nutrients.

Loss of Volume and Soil Sealing
Urbanization has also led to increasing soil volume loss. As urban areas, roads, and industrial zones expand, large land areas are covered with asphalt, concrete, or other impermeable materials, known as soil sealing. In Europe, an estimated 890 km² of soil is sealed annually, reducing arable land and the soil’s ability to absorb water, increasing flood risks, and lowering water storage capacity.

Focus on Sustainable Soil Management
There is a growing trend toward sustainable soil management methods, such as agroforestry, regenerative agricultural practices, and minimal soil tillage (plowing). These methods aim to restore soil structure and organic content, helping to increase soil fertility, water retention, and carbon storage capacity. Sustainable management can also help slow down erosion and reduce soil volume loss in the long term.

Innovative Technologies and Solutions
Technological advancements play a vital role in preserving soil quality and volume. Numerous innovative solutions have been introduced, such as digital soil monitoring, the use of drones to analyze nutrient and moisture levels, and the development of machinery that can clean contaminated soil and reclaim arable land. An example is our SoilSaver, which effectively combats harmful microorganisms without polluting the soil with chemicals. It also removes seeds and plant parts from invasive species, which would otherwise require the disposal of large volumes of soil.

The Way Forward
Ensuring the quality and volume of soil requires collaboration between agriculture, the technology sector, and governments. World Soil Day provides an opportunity to reflect on how we can better care for our most valuable resource. Supporting sustainable management practices, increasing the use of innovative technologies, and engaging society in soil conservation may be the key to maintaining productive soil for future generations.

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