Compost activator

Biochar creates the Terra Preta effect. It provides a habitat for microorganisms and acts as a reservoir for water and nutrients. It absorbs nutrients and water like a sponge and releases them as needed, much like an open fridge from which the plants can take what they need. Thanks to the buffering effect of the biochar, over-fertilisation when replenishing the soil is virtually impossible. Our biochar is included in the following Sonnenerde products: our Terra Preta Schwarzerde, our Terra Preta soil concentrate Schwarzerde Konzentrat, our hemp soil Hanferde, our soil activator Bodenaktivator, our compost activator Kompostaktivator, our urban tree fine substrate Stadtbaum Feinsubstrat, our urban tree concentrate Stadtbaum Konzentrat.

Pieces of wood are a natural component of our compost and do not constitute a quality defect. All our products are screened using a trommel screen during processing. A specific mesh size is used to remove coarser particles. However, individual pieces of wood may remain in the product if their diameter is smaller than the respective mesh size. This is due to technical constraints and is also a reflection of our conscious commitment to gentle, nature-friendly processing.

We firmly believe that plastics have no place in nature and therefore have no place in our soils either. That is why we invest a great deal of time, money and energy into keeping our products free from contaminants. We deeply regret it when, despite our best efforts, very occasional plastic particles find their way into our products.

In this regard, we would like to give you a brief insight into some of our quality assurance measures:

Selection of raw materials: We use only regional tree and shrub cuttings, as well as controlled sludge (e.g. from jam production and milk processing), to produce our compost. We have made a conscious decision not to use the contents of organic waste bins, as these contain vast quantities of packaging materials, plastic bags and other contaminants.

Inspection on delivery: Unfortunately, it is a widespread social problem that waste is often carelessly discarded in the natural environment. Consequently, tree and shrub cuttings are sometimes contaminated with plastic. The raw materials delivered are always checked by our staff for contaminants. Obvious contaminants such as plastic flower pots or similar items are sorted out by hand before processing. In cases of severe contamination, acceptance is consistently refused.

Technical processing: Despite careful raw material selection and inspection, we cannot entirely prevent isolated pieces of plastic from entering the raw material mix for our compost. To separate these particles before processing into the final product, the finished compost is sieved using a defined mesh size.

External quality controls: Our composts is inspected several times a year by external, independent testing bodies. A key component of these inspections is the sampling and laboratory analysis of the compost. The test results are published on our website to ensure the greatest possible transparency. The analysis also examines the compost for contaminants (see ‘Table 3: Test results for dietary fibre’). Compliance with the Austrian Compost Ordinance is certified in Chapter ‘4. Compost Assessment’ through classification into Quality Class A+ (our organic compost Bio Kompost) or Quality Class A (conventional compost). Plastics in particular are extremely difficult to separate due to their material properties (e.g. low weight, low resistance to mechanical stress, non-magnetic…). Even more intensive technical processing of our compost to separate the last, very isolated plastic particles (according to compost test results < 0.2%) is by no means proportionate to the associated environmental impacts (e.g. CO2 emissions from the additional energy consumption). As a company committed to environmental sustainability, we could not condone this. Furthermore, to our knowledge, there is currently no process that allows for the complete separation of plastics. We therefore ask that any plastic parts found be removed by hand. We would also be delighted to invite you to visit our premises in person to see for yourself. Once a year (on 1 May), as part of our open day, we even offer free guided tours with our CEO Gerald Dunst, during which all our work processes are demonstrated and explained. As a company dedicated to the sensible recycling and recovery of biogenic waste on a daily basis, we take our responsibility towards nature very seriously!