Bio-based soil improvers

A soil improver is a substance applied periodically to soil to improve its fertility. Bio-based alternatives
are compost, mulch and sludge and can be made from various waste streams.


Resource efficiency: For the production, waste streams are used. The market for secondary raw materials and the circular economy in general will be stimulated through this transition.
Reduced GHG Emissions: It will contribute to combating climate change.
Reduced environmental impact.
Reduced impact from mining of peat: Replacing the use of peat with compost will reduce peat demand.
Reduced impact from transport of soil improvers: Compost and sludges are available and processed locally.
Reduced waste: By using green waste and sludges as soil improvers, this waste stream is diverted and utilised
as a resource.
Reduced costs: One example found a mixture of peat, bark and brick to cost approximately £25/m3 while a mixture of green compost and bark cost approximately £19/m3.

Potential Barriers

Costs: Application costs and maintenance costs differ and depend largely on the original situation. Application of sludge might be more work than application of mineral fertilizer. However, the application of additional water (in the sludge) might increase yield and reduce the need for irrigation.
Availability: Bio-based soil improvers are available in France, Germany and the Netherlands, Poland, Belgium and Italy.
Quality of the products: The quality of bio-based soil improvers can fluctuate. For this reason it is
recommended that quality controlling criteria, as presented under the second category of procurement criteria
(quality of the soil improver) are incorporated in the tender.