Key Takeaways
- Early trials in Belgium reported steamed, reused strawberry substrate performing similarly to new substrate.
- The company cites treatment costs of about $5–$10 per cubic unit versus new substrate at roughly $50–$80.
- Plans include multiple machine sizes and near-term expansion to North America, starting with Canada.
Background And Use Cases
Speaking on the Vertical Farming Podcast, Hans Kristian Westrum explained how requests from road and rail contractors led Soil Steam to adapt agricultural steaming to construction projects, allowing contaminated or invasive-weed soils to be treated on-site rather than landfilled.
“If you have the wrong diseases or the wrong weeds in the soil, that soil has to be trucked away to a landfill. Extremely expensive and not really sustainable,” he said.
Technology And Controls
The steam generator concept is traditional, but sensing and control are modernized. Hans Kristian Westrum noted that different targets require different heat profiles:
“Some weeds… you have to go up to more than 90°C for maybe five or 10 minutes, while many organisms and fungi and nematodes… die at maybe 60 or 65, 70°C.”
Field observations also indicated microbial rebound: “Two weeks later… 80% of the natural soil-borne life was back.”
Trials In Substrates
Prompted by growers, an electric unit was tested at a Belgian research center on previously used strawberry substrate. According to Hans Kristian Westrum, early measurements (sprouting, root development, color, and later yield/shelf life) showed steamed, reused substrate tracking closely with new substrate, while untreated reused material lagged.
Market Rollout And Pricing — Hans Kristian Westrum
With growers seeking sanitized media before first use and options to recycle, Hans Kristian Westrum said Soil Steam’s containerized systems range from high-throughput units (approx. 30–40 m³/hour) to smaller farm-scale models.
On costs, he stated: “We can recycle one cube of the substrate at the cost of maybe five to ten dollars,”
While new substrate “between $50 and $80 per cube” is common in some markets. The company plans to place technicians and sales support in Canada as part of a North American rollout.
