Tree nurseries play an important role in keeping our world livable. Especially now, with urbanization, climate change, and the decline of our ecosystems being three major developments, we need plants to increase our wellbeing. After all, studies show that nature relieves stress, promotes an active lifestyle, and creates social cohesion.
Fit for purpose, sustainability in tree nurseries
A sustainable substrate is first and foremost a substrate in which the cultivated crop grows most effectively. In addition, sufficient space for the grower to control or steer is required. The match between a substrate and the growing process at the grower is what makes cultivation, and therefore a substrate blend, effective. A Substrate in which a plant grows poorly is not an effective and therefore not a sustainable growing medium. After all, it’s free of weeds and pathogens, and its buffering capacities are excellent. Besides that, many growers love the way moisture behaves within the peat. Because of all these factors, peat is a sustainable material if you think about it from a “fit for purpose” perspective. Although extensive research has been conducted throughout the industry, no other raw material has yet been found that offers the same versatility as peat.
Complimentary raw materials
However, there are other materials that, combined with peat, also produce high–quality substrates. You can think of raw materials such as Sphagnum moss, wood fiber, bark, and coir.
It is impossible to completely substitute peat with these other raw materials in all of horticulture. However, people can use them to reduce the share of peat within a mixture. These materials can also be used to complement certain properties. It entirely depends on the crop and the processes at the grower how to create a substrate that is fit for the purpose.
Different materials do need different pretreatments. They often also require adjustments within the growing methods used. In conclusion, all these materials also have their advantages and disadvantages. Coir, for example, needs to be chemically treated before use to prevent the release of salts during cultivation, and adding wood fiber requires changes within a grower’s fertilization strategy because it can influence the nitrogen requirement of the recipe.
Peat in sustainable substrates
In the discussion about the use of peat in substrates, people often only focus on a perceived CO2 emission but fail to properly look at the harvesting processes. European peat for substrates is harvested responsibly (certified by RPP) from already degraded wetlands. As a result, the biodiversity after the restoration of the peatlands (which is mandatory) is greater than before the extraction. Furthermore, peat harvest for growing media only takes place in an area the size of 0.05% of all peat areas worldwide. Want to know more about peat use and how it’s harvested? Have a look at Kekkilä-BVB’s website.
Show the real impact through a life cycle analysis
That means that if you want to create the most sustainable substrate, you need to look at all the aspects involved, and not just one.
At Kekkilä-BVB, they look at the chemical, physical and biological properties of the material, as well as its availability. But also use a life cycle analysis (LCA) to minimize the value chain impact. Check out the article on the company website if you would like to know more about the LCA.
In summary, if you care about sustainability, you need to be mindful of the implications for the cultivation methods, but you should also take one step back and look at the sourcing of the raw materials. This is something the entire sector needs to do responsibly, both environmentally speaking and socially speaking. Next to that, you should see if raw materials can be sourced locally to reduce logistical impact. That leads to checking if it can produce the substrate efficiently and safely and thinking about possible options for a second life.
For more information:
BVB Substrates
info@bvb-substrates.nl
www.bvb-substrates.nl/en