Dutch nursery growers visit Soilcom trials

13 October 2021 - Published by Hanne Lakkenborg Kristensen
Written by Delphy.


On the 24th of September Delphy organised a field day at her Research Nursery. 120 growers visited the Soilcom compost trails. There was an explanation of the Soilcom project and the added value of compost. Delphy showed the application of compost in soils. As well as the application of compost in pots. 

Last two years Delphy was testing the application of various composts on top of the soil in a field of Boxwood. Boxwood is a fast growing crop with a high nutrient requirement, sensitive roots and shallow rooting.

This year Delphy also started a pot trial. Plants were potted in different potting soil compositions. The compost was mixed with the potting soil in two different amounts: 20% and 40%. A standard potting soil has been used as a reference. The following crops were used for this demo: Hydrangea paniculata and Juniperus chinensis 'Stricta'. These crops show strong root growth and salt tolerance. Growers are very interested in reducting the amount of peat in the potting soil. Growers, visiting the field day, could see the good crop color and root development. Tthe results exceeded their expectations.  They concluded that the pots with 40% compost were much heavier in weight.  For some markets this can even be an advantage.

In Holland the use of compost in potting soil is permitted within the RHP certification mark. With a maximum of  20%. Higher is not permitted.  The demo makes it clear that higher doses are possible for certain, less sensitive, crops.