Factsheet bio-based soil improvers.
Date: 2018-05-26
Institutions: Directorate-General for Internal Market, Industry, Entrepreneurship and SMEs
Subjects: award of contract, eco-label, environmental impact, green public procurement, organic fertiliser, soil conditioning

FACTSHEET BIO-BASED SOIL IMPROVERS 

Procurement of Innovative Products: Bio-based Products in Procurement 
15-05-2017 

Why bio-based soil improvers? 
What are (bio-based) soil improvers? 
A  soil  improver  is  a  substance  applied  periodically  to 
soil  to  improve  its  fertility1.  Examples  of  conventionally 
used soil improvers are peat and mineral and synthetic 
fertilizer. Bio-based alternatives to these soil improvers 
are  compost,  mulch  and  (non-sewage)  sludge.  Bio-
based  soil  improvers  can  be made  from  various  waste 
streams.  This  factsheet  provides  information  on  bio-
based  soil  improvers  and  how  to  take  these  into 
account in procurement. 

Why  should  organisations  consider  bio-based  soil 
improvers in procurement? 
Organisations  could  consider  bio-based  soil  improvers 
in  procurement  if  they  would  benefit  from  one  or  more 
of  the  capabilities  attributed  to  the  bio-based  soil 
improvers.  Bio-based  soil  improvers  potentially  have 
different  capabilities.  Aspects  to  keep  in  mind  are 
environmental  impact  over  the  life  cycle  of  the  product 
(this  could  be  determined 
through  Life  Cycle 
Assessment  in  accordance  with  ISO  14040)  and  the 
sustainable sourcing of the input material (this could be 
assessed  in  accordance  with  the  sustainability  criteria 
for  biobased  products  from  EN  16751  in  combination 
with  CEN/TR  16957  -  Bio-based  products  -  Guidelines 
for Life Cycle Inventory (LCI) for the End-of-life phase). 
With  this  kept  in  mind,  several  potential  benefits  can 
also be attributed to bio-based soil improvers2.  
  Resource  efficiency:  For  the  production  of  bio-
based  soil  improvers,  usually  waste  streams  are 
used.  Conventional  soil  improvers  are  peat,  which 
is a fossil material, mineral fertilizers which require 
energy  to  mine  and  synthetic  fertilizers,  which  are 
following  an  energy 
made 
intensive  process.  The  switch  to  bio-based  soil 
improvers  will 
resource 
efficiency.  In  addition,  the  market  for  secondary 
raw  materials and  the circular  economy  in  general 
will be stimulated through this transition.  

therefore 

improve 

fossil 

fuels 

from 

emissions  will  in  turn  contribute  to  combating 
climate change.  

  Reduced  environmental  impact:  Bio-based  soil 
the 
the  potential 
improvers  have 
environmental  impact  compared  to  conventional 
soil improvers:   

reduce 

to 

Reduced  GHG  emissions  The  life  cycle  GHG 
emissions  of  different  composting  methods, 
materials  and  substitutes  were  assessed  by 
Boldrin  et.  al.,  (2009).  In  the  case  of  compost 
substituting peat, it was found that a saving in the 
order of 183 kg CO2-eq per tonne of compost was 
achieved.  Substitution of mineral  fertilizers  would 
save  emissions of  the  order  30.3–89.5 kg  CO2-eq 
per  tonne  of  compost.  Source:  Boldrin  et  al., 

(2009),  Composting  and  compost  utilization: 
accounting  of  greenhouse  gases  and  global 

warming contributions.  

o 

o 

o 

from 

Reduced impact from mining of peat. Peat is 
a non-renewable material which needs to be 
extracted 
the  soil.  This  extraction 
results  in  loss  of  natural  ecosystems  and 
subsequent  loss  of  biodiversity  and  species. 
Replacing  the  use  of  peat  with  compost  will 
reduce  peat  demand  and  therefore  mitigate 
the impact of peat mining.   
Reduced 
transport  of  soil 
from 
impact 
improvers.  Majority  of  peat  is  found  and 
the  United  Kingdom  and 
extracted 
Scandinavia. Fertilizers are usually produced 
on a large scale at central facilities. Compost 
and  sludges  are  available  and  processed 
more  locally.  This  difference  in  distribution 
will result in reduced transportation distances 
and therefore reduced GHG emissions.   
Reduced  waste:  By  using  green  waste  and 
sludges as soil improvers, this waste stream 
is diverted and utilised as a resource.  

in 

the 

  Reduced  Greenhouse  Gas  (GHG)  Emissions: 
Depending  on 
the 
production  process  and  the  type  of  conventional 
soil  improver  which  is  replaced;  bio-based  soil 
improvers have the potential to reduce Greenhouse 
Gas  Emissions.  Reduced  greenhouse  gas 

raw  material  used, 

1 Definition adapted from ‘EU GPP Criteria for Gardening products and 
services’.  
2  These  benefits  can  differ  between  products  and  should  always  be 
confirmed by the supplier.  

  Reduced  costs:  The 

initial  costs  of  compost 
compared to peat and sludge compared to mineral 
fertilizer  is  usually  lower.  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.The 
cost  during  management  of  the  crop  depends 
mostly  on 
the  compost  and 
management practices.  

the  quality  of 

 
 
                                                           
 
 
How to take into account the specific capabilities of soil improvers in procurement? 

Procedures and purchasing strategies  
Procurement  within  the  gardening  and  landscaping 
sector  often  implies  procurement  of  services  or  works. 
Soil  improvers  are  likely  to  be  procured  as  part  of  a 
service  or  works  contract  or  form  part  of  a  supply 
contract  for  other  products,  such  as  plants.  The 
capabilities  of  the  bio-based  soil  improvers  could  be 
described  in  terms  of  general  constituents  (which 
addresses  aspects  such  as  resource  efficiency  and 
reduced  environmental  impact)  and  quality  of  the  soil 
improver. The quality of bio-based soil improvers tends 
to vary. Therefore the second criterion on quality of the 
soil improver is included.   

Examples of procurement criteria  
The  EU  Green  Public  Procurement 
(GPP)  has 
developed  core  and  comprehensive  criteria  for  soil 
improvers.  It  is  recommended  that  these  criteria  are 
assessed  on  their  applicability  and  if  relevant  used  for 
the  procurement  of  soil  improvers.  In  this  fact  sheets 
the  criteria  developed  by  the  EU  GPP  are  presented 
and  grouped  into  1)  General  Constituents  and  2) 
Quality  of  the  soil  improver  (EU  GPP  Criteria  for 
Gardening products and Services3).  

1.  General Constituents 
Minimum Requirement 1: The soil improvers to be used 
in  carrying  out  the  service  must  not  contain  peat  or 
sewage sludge.  

Minimum  Requirement  2:  Organic  matter  content  must 
be derived from the processing and/or reuse of waste. 

Minimum  Requirement  3:  Sludges  are  allowed  only  if 
they are identified as one of the wastes according to the 
European list of wastes.  

Additional  information:  Waste  has  been  defined  in 
Council  Directive  2006/12/EC  of  April  2006  on  waste 
and  its  Annex  I.  Sludge  waste  has  been  defined  by 
Commission  Decision  2001/118/EC  of  16  January 
2001.  

Verification:  Tenderers  must  provide 
the  detailed 
composition  of  the  product,  the  origin  of  the  organic 
matter  and  a  declaration of  compliance  with  the  above 
requirements. Products holding a relevant label fulfilling 
the  listed  criteria  will  be  deemed  to  comply.  Other 
appropriate means of proof, such as a technical dossier 
of  the  manufacturer  or  a  test  report  of  an  independent 
body, will also be accepted.  

3http://ec.europa.eu/environment/gpp/pdf/criteria/gardening.pdf  

2.  Quality of the soil improver 
Minimum  Requirement  1:  Maximum  concentrations  of 
heavy metals in the waste before treatment (mg/kg dry 
weight)  must  meet 
requirements  below  on 
hazardous substances. In the final product, the content 
of the following elements shall be lower than the values 
shown below, measured in terms of dry weight:   

the 

Element  Mg/kg (dw) 
Zn 
Cu 
Ni 
Cd 
Pb 
Hg 

300 
100 
50 
1 
100 
1 

Element  Mg/kg (dw) 
Cr 
Mo (*) 
Se (*) 
As (*) 
F (*) 

100 
2 
1.5 
10 
200 

(*) Data relating to the presence of these elements are 
needed  only  for  products  containing  material  from 
industrial processes.  

Minimum  Requirement  2:  In  the  final  product,  the 
content of the glass, metal and plastic (the sum of each 
contribution)  shall  be  lower  than  0.5%  as  measured  in 
terms of dry weight. 

Minimum  requirement  3:  The  concentration  of  nitrogen 
in  the  product  shall  not  exceed  3%  total  N  (by  weight) 
and  inorganic  N  must  not  exceed  20%  total  N  (or 
organic N > 80%).  

Minimum  requirement:  4:  Products  shall  not  adversely 
affect  plant  emergence  and  subsequent  growth,  and 
shall  contain  not  less  than  25%  dry  matter  by  weight 
and not less than 20% organic matter by dry weight 

Minimum requirement 5: Products shall not exceed the 
maximum levels of primary pathogens as follows 
Salmonella: absent in 25g of product 
Helminth Ova: absent in 1.5 g of product 
E.coli: <1000 MPN/g (MPN: most probable number) 

(EN  13650, 

Verification:  Tenderers  must  provide  the  relevant  test 
reports 
ISO  16772  or  equivalent) 
demonstrating  that  the  above  requirements  are  met. 
Products  holding  a  relevant  label  fulfilling  the  listed 
criteria  will  be  deemed  to  comply.  Other  appropriate 
means  of  proof,  such  as  a  technical  dossier  of  the 
manufacturer  or  a  test  report  of  an  independent  body, 
will also be accepted.  

 
 
 
 
 
 
 
 
 
 
 
 
 
                                                           
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
What soil improvers are available? 
The following databases contain information on the availability of bio-based soil improvers: 

  The  ‘Datenbank  FNR’  database  (Germany)  provides  an  overview  of  bio-based  soil  improvers.  Information  on  the 

product, supplier and whether the product is certified is available within the database.  

  The ‘CoE BBE’ database (the Netherlands) provides information on a bio-based soil improver. Information about the 

producer, product characteristics and whether the product is certified is specified. 

  The  ‘Agrobiobase’  database  (France)  provides  an  overview  of  bio-based  soil  improvers,  as  well  as  product 

specifications and whether the product is certified.  

Points of attention 
The following potential barriers and bottle necks have been identified by procurers, policy makers and professionals that 
work  with  bio-based  products  in  procurement.  The  relevance  of  each  of  these  potential  barriers  is  discussed  for  the 
product group ‘soil improvers’: 

  Costs:  the use  of sludge as a  replacement  of mineral fertilizer  and  compost  as  a  replacement  of peat are  usually 
found to reduce purchase 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. Other costs, such as 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.  

  Level  of  development:  The  databases  ‘FNR’,  CoE  BBE’  and  ‘Agrobiobase’  all  provide  a  range  of  bio-based  soil 

improving products. Based on this information, the level of development is considered mature.  

  Availability:  Bio-based  soil  improvers  are  available  in  France,  Germany  and  the  Netherlands,  following  the 
information  on  the  above  mentioned  databases.  An  online  internet  search  also  confirms  availability  in  other 
European countries such as 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.  

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
“The  information  and  views  set  out  in  this  report  are  those  of  the  author(s)  and  do  not  necessarily  reflect  the  official 
opinion of EASME or the Commission. EASME and the Commission do not guarantee the accuracy of the data included 
in this study. Neither EASME or the Commission nor any person acting on EASME's or the Commission’s behalf may be 
held responsible for the use which may be made of the information contained therein.” 

Catalogue number 

ISBN 

DOI 

ET-04-18-607-EN-N 

978-92-79-89449-7 

10.2873/857820 

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Disclaimer: The information and views set out in this report are those of the author(s) and do not necessarily reflect the official opinion of 
EASME  or  the  Commission.  EASME  and  the  Commission  do  not  guarantee  the  accuracy  of  the  data  included  in  this  study.  Neither 
EASME or the Commission nor any person acting on EASME’s or the Commission’s behalf may be held responsible for the use which 
may be made of the information contained therein.