Van der Knaap Group and Comgoed Substrates showcase the future of circular raw materials at a client event

Florus van der Paauw, board member and co-founder of Comgoed, opened the afternoon at the venue, which had been festively decorated to mark their 25th anniversary. During his presentation, Florus spoke about the history of Comgoed, thanked everyone for coming to the venue, and he and Twan playfully pointed out that the venue is not in Zeeland, but just within South Holland.

At Comgoed, there is a strong belief in the reuse of raw materials, a trend that will only become more important in the future. Comgoed Substrates, one of Comgoed’s divisions, specialises in sanitising used substrates from the horticultural sector. With great passion and dedication, the company is working towards a greener world, where circular and sustainable solutions are the norm.



Next, the floor was given to Twan van den Berg, director of the Substrates business unit at Van der Knaap Group. Twan gave a brief introduction to the company, which develops and produces innovative, high-quality growing media and circular fertilisers. Van der Knaap Group supports growers with renewable and circular raw materials, helping to increase yields and reduce the ecological footprint.

Circular raw materials
In 2022, the growing media sector, public authorities and NGOs drew up a covenant aimed at reducing the environmental impact of growing media. The target for 2025 – the use of 35% renewable raw materials in the professional market – was achieved last year. At the same time, demand for growing media is expected to quadruple by 2050. In addition to the quality of new raw materials, ensuring sufficient supply volumes also poses a major challenge.

These developments have accelerated sustainability and innovation within the sector. In addition to the development of the quality mark for responsibly extracted peat (RPP), the use of renewable and circular raw materials will also need to increase. Van der Knaap Group has been conducting research into this for years. This includes work at its own innovation centre ‘de Kas’, using highly comprehensive test programmes.

Circular innovation in practice: Green Soil
The first discussions between Van der Knaap Group and Comgoed Substrates took place as early as July 2021. Ultimately, this collaboration led to the development of a new circular raw material: Green Soil. The RHP was also involved in the process and has since granted producer Comgoed the RHP certificate for use in horticulture.

The base material (a waste stream) used in Green Soil comes from soft fruit cultivation. This material is collected via a return system. Both companies closely monitor the quality of both the raw materials and the end product. For instance, strict phytosanitary requirements apply to the waste streams. Materials that do not meet these requirements are not processed into the substrate. The processing procedure also follows strict protocols. For instance, the material must be kept at a temperature of 70 °C for 100 hours to sanitise it. In addition, several quality checks are carried out: before the raw material is transported from Comgoed Substrates, after the production process, upon arrival at Van der Knaap Groep, and prior to delivery to customers in the floriculture sector. In this way, the quality of Green Soil is guaranteed throughout the entire process.

The characteristics of Green Soil are comparable to those of garden peat. The substrate contains virtually no ballast salts, such as sodium and chloride, has good water-holding capacity, and also has an air content and bulk density comparable to those of garden peat. Green Soil is also an affordable option. There is a financial and sustainability benefit for the grower who supplies it and the nurseryman who uses it in his substrate mix, as the use of this recycled raw material contributes to a lower ecological footprint.



The First Sustainable Generation
The final speaker of the afternoon was Marco van der Sar, one of the initiators of ‘The First Sustainable Generation’. In his talk, he demonstrated how growers, thinkers and doers can work together to build a world in which sustainability and prosperity reinforce one another. What began as a journey through Costa Rica grew into a manifesto and a range of projects focusing on media, education and politics.

According to Marco, professional agriculture and horticulture fit seamlessly with this vision; by producing more on less land, there is more space for nature. He envisions a future in which both people and the planet can flourish thanks to efficiency, innovation and entrepreneurship. His presentation offered an optimistic and forward-looking perspective and gave the audience food for thought.



Guided tour and conclusion
The presentations were followed by a guided tour of the Comgoed Substrates site in Middelharnis (still in South Holland, despite the Zeeland flag flying from the flagpole). This site is where, among other things, the Green Soil is sanitised. Those present were given an insight into the entire process and were visibly impressed by the professionalism with which it is carried out. They were also shown the storage area for the Green Soil stock, which will soon be transported to the Van der Knaap Group for use in RHP substrates.

The afternoon concluded with a delicious snack, provided by Comgoed Substrates, back at the site in Dirksland. Whilst enjoying the sunny weather, there was a lively discussion about the presentations, the collaboration and the future of circular raw materials within the sector.



Further information
Would you like to receive further information about the circular raw material Green Soil? Please get in touch with us.

Van der Knaap Group
vdk@vanderknaap.info

Comgoed Substrates
info@comgoed.nl