Optimizing compost by joining SOILCOM

10 March 2022 - Published by Hanne Lakkenborg Kristensen
With the new insights and experiences of SOILCOM, Klintholm I/S In Denmark, changed its composting processes. As a result the compost quality increased. The Danish Klintholm I/S participates in the SOILCOM project.

Written by Esther Hessel.


Martin Johanssen, director of Klintholm I/S, is happy with the changes in the compost quality. Together with Hortiadvice Scandinavia and the experiences within SOILCOM, Klintholm worked on optimizing the input streams as well as the composting process. Private households bring their garden material to the composting facility. In summer more grass is brought to the composting facility, as in autumn more woody material is delivered.  In contrast to earlier, the input streams are sorted and shredded. The larger parts will be fuel for a waste incineration plant. The smaller material gives a more uniform composting process. 

Instead of one or more big piles of material, now three windrows are made. During the process temperature and moisture are measured. The composting process is more controlled. Johanssen: “together with HortiAdvice we are especially working towards a controlled product without pathogens and nematodes. We have experienced that the water content of the rows is very important. In the process we add therefore now also more water”. Johanssen adds that there is still a long way to go, but steps are made towards better compost and also adoption of compost by farmers.


Market for composts

Till now farmers were reluctant to use the compost. Besides the addition of organic matter, they were afraid of adding also plastics and heavy metals. There is enough manure in Denmark and the farmers experienced no added value of using the compost. The compost was only used as a fertilizer.  But this is also changing now. Especially organic farmers are actively working on soil quality and biodiversity in the soil. They see that compost can help in the process of soil improvement.  

Recently, Johanssen joined a webinar with organic growers. A very crucial remark was made there: “when using the compost for soil improvement in treenurseries, you have to look for the long term effects. Maybe we have to approach it as forestry, were you are building on long term soil improvement”.

Together with HortiAdvice Scandinavia a trial was developed to apply compost in treenurseries and vegetable cultivation. Follow the news to see the results in 2022!