In the Dutch Boskoop area potential organic bioresources are tested for their use as potting substrates. At the research station of Delphy different mixes of substrates are tested to measure the effects on plant growth. Now starting with conifers. But coming years also trials in for example perennials will be carried out. In the Boskoop area the Dutch CLOSECYCLE partners, Delphy and the Greenport Boskoop, brought the partners of the local network together.
Greenport Boskoop is a regional authority in the Boskoop region. It has a lot of experience in advocacy in the region and therefore many contacts with growers, suppliers, governments and the Water Board. In the showcase Delphy and Greenport have regular meetings were CLOSECYCLE is one of the agenda items. In the meetings last years the conversion about peat free substrates and other potential bioresources increased. And the foundation has been layed for the activities of CLOSECYCLE. In the area three interesting local streams are investigated for their possible use. Often in combination with other more know bioresources, as for example miscanthus.
- Vegetable, fruit and potato residues from citizens (bio bin compost); experience in Boskoop is that this stream has improved a lot and is quite interesting for using as potting substrate;
- Sludge from local ditches and canals. Starting with a large dredging project in the polder of Berkenbroek now the sludge is used in the trials for substrates. In the near future two other dredging projects in two local polders will start.
- Dried fraction of cow manure. In cooperation with LTO, the leading business organization for Dutch farmers and horticulturalists, Greenport and Delphy are now investigating the use of processed dried cow manure for potting substrates.
Combinations and mixes of the different substrates are made based on the technical experience of Delphy. But also in close contact with RHP. Dutch potting substrates need to be RHP certified. The objective of RHP quality mark is to increase the security that the substrate complies with the quality requirements concerning for instance water uptake, air content, pH, EC and nutrients. For the Boskoop showcase the contacts and discussion with RHP are very important. New questions arise and solutions for problems and challenges are found.
Network
Both Delphy and Greenport have an already long existing, extensive network. That makes that building the Territorial Biorefinery Network is more easy. But also important. The biorefinery network is not based on some companies, but exists of a lot of partners along the chain of production, processing and use of end products.
Till now the possibilities of the potential of using sludge by tree growers for substrate was not in the picture by both dredgers and tree growers. This is what is now investigated. In the case of the cow manure, LTO dairy farming investigated the processing of the fresh cow manure. Contacts between LTO and Greenport led to investigating the added value of dried cow manure in the tree nursery.
Bringing the right people together is one. But to see what the effects are of using these bioresources in substrates for tree nurseries is the second important step. At the research station, Delphy has welcomed municipalities, water agencies, provinces and tree growers to see and discuss the trials with the different mixtures. During the season, Delphy carries out measurements to make the possible differences visible. At the end of the trial also dry matter content is measured of the different treatments.
Every year the results of the trials are evaluated and a plan for the coming year is developed. Plans for the mixtures and the scale of the trials are made. The results are presented to the growers, municipalities and provinces. But are also used for informing the policy makers about the challenges and barriers in legislation. Especially Greenport Boskoop plays an important and pioneering role in informing and discussing with policymakers.