Storage of greenhouse foliage with biodegradable materials

Since greenhouse waste streams are typically generated at the same time, an effective storage solution is required. Proper storage will enable the gradual blending of smaller waste fractions into regular composting processes. The expertise of farmers and compost facilities is crucial in evaluating the use, suitability, degradation, and compostability of bio-based materials within various composting processes, completing the showcase. However, compostability remains a challenge. In addition, these foliage residues become available in a short period of time in the fall.

To explore short- to medium-term storage strategies, a pilot trial was launched in June 2025 at the research station, focusing on the preservation of cucumber vines through small scale and large scale silage. Throughout the trial, internal temperatures are monitored continuously and at the end, parameters such as pH and ammonia levels will be measured to assess preservation quality.

By trying to store the material over a longer period, the material can be used for composting on a later moment. The method of ensilling or wrapping the material in bales is considerd.

Optimising plant waste flows through storage solutions

Cucumber cultivation illustrates a major logistical challenge: at the end of the growing season, over 90% of the plant material becomes available within a very short time. Currently, only a small portion of this biomass is composted. As greenhouse agriculture transitions toward more circular and sustainable practices, immediate composting of all plant residues is impractical and could create logistical problems.

One of the central questions within the CLOSECYCLE project, conducted at the research station, is whether it is possible to store plant material effectively and initiate composting after storage. If feasible, this would allow the material to be used over a longer period, rather than all at once. Different storage techniques will be explored to support this phased approach to composting.

Pilot study: Silage of cucumber vines

To explore short- to medium-term storage strategies, a pilot trial was launched in June 2025 at the research station, focusing on the preservation of cucumber vines through silage. For this study, bokashi buckets were used to test different combinations of materials:

Control: cucumber vines only
Cucumber vines with 10% and 20% chicory roots added for their high sugar content, which enhances fermentation and lowers pH
Cucumber vines with a silage additive (TMR+) which improves fermentation quality and inhibits mold development

Throughout the trial, internal temperatures are monitored continuously and at the end, parameters such as pH and ammonia levels will be measured to assess preservation quality.

Toward scalable circular solutions

In August, the research entered a new phase with the launch of a large-scale silage trial. Around 2 tons of cucumber plant residues were ensiled to test the method under practical, real-world conditions. The batch was divided into two treatments:

One part was ensiled with the TMR+ additive
The other part was ensiled without any additive

The effectiveness of preservation, ease of handling, and quality of the stored material will be compared across treatments.