Model calculates mixtures with peat alternatives

October 31, 2023

The use of peat in potting soil and substrate is under pressure. That is why producers are looking for alternative ingredients. The aim is for professional substrate to consist of 35% renewable raw materials by 2025 and at least 90% by 2050. Producers off course want to know what properties such a new substrate has. That is why the Greenhouse Horticulture and Flower Bulbs Business Unit of Wageningen University & Research is developing a model with which a producer can calculate the composition of a mixture online.

The model allows the composition of a substrate to be entered: the user can indicate the ratio per ingredient. The model then calculates, among other things, the levels of nitrogen, phosphorus, potassium, PH, EC, the dry bulb density and the amount of organic substances. This allows producers to develop a substrate that is as peat-free as possible and still has good cultivation properties.

WUR already had an Excel model for calculating the properties of a substrate. This outdated model is being updated and converted into a new form (Python), so that it can also be used online and can be more easily expanded with new possible ingredients. That online version will be published in 2024. The updated model now contains calculations for 18 different substrate mixtures.

Next year, some members of the Club of 100 - which co-finances the research - will test the online version. In addition, WUR will validate the model: the substrates are actually examined for this. The model and online version will be ready in 2024.