Biochar: Mechanisms and socio-economics of carbon sequestration and soil quality (completed)

Biochar is charcoal from pyrolysis of organic waste. When mixed into soil, biochar is stable, and thus its carbon is removed from the carbon cycle. This mitigates climate change. Due to its alkaline reaction, biochar also increases soil quality by reducing soil acidity. Particularly, in Asia, with its extensive areas of acidic soils, this is very relevant, as soil acidity reduces crop yields. We aim at investigating the potential of biochar from organic waste to sequester carbon and improve soil quality and thus livelihoods.

About the project

This FRIMURF project is closely linked to the NORGLOBAL project Biochar on acidic agricultural lands in South-East Asia: Sequestering carbon and improving crop yield

Both projects involves social and agricultural/environmental components. Social-scientific components include biochar generation
concepts and a life cycle assessment comparing use of biochar to conventional energy production and fertilizer use, specific for tropical
conditions. Life cycle cost assessment will address investments, income, and revenues. The agricultural/environmental part consists of initial chemical
screening of soil-biochar combinations, followed by extensive pot and field trials as well as mechanistic lab studies.
The proposed research addresses the call, as it integrates environmental and development science, with its focus on the potential of biochar to
increase carbon sequestration, while at the same time contributing to sustainable land use. The project is multidisciplinary and integrates social,
agricultural, and environmental sciences. The Indonesian Embassy in Norway supports the proposal.


1. Biochar characterization and effectiveness:

1A. A systematic study of successful and non-successful soil-biochar combinations.
1B. Identify optimal pyrolysis (biochar generation) and optimal feedstocks.
1C. Study long-term stability of biochar in acid tropical soils.
1D. Study effects of biochar on soil acidity, aluminium toxicity, organic matter degradation, nutrient availability / fertilizer need, inhibition of the production of greenhouse gases nitrous oxide and methane.
1E. Biochar mechanisms: GHG binding and microbiology.

2. Biochar generation/implementation:

2A. Develop concepts for successful biochar generation.
2B. Socio-economic environmental impact and life cycle cost analysis over the whole life cycle at the farmer and entrepreneur level.


Biochar: the principle: Biochar is the charcoal product obtained when biomass (preferably organic waste) is heated without access to oxygen (pyrolysis). In contrast to organic material, biochar is stable for hundreds to thousands of years when mixed into soils, and thus represents carbon that is actively removed from the carbon cycle.

Biochar is carbon negative and a source of alkalinity: First, plants assimilate CO2 from the air through photosynthesis and accumulate the C as biomass. Half of this CO2 is returned to the air as biochar is generated, along with energy.

The other half is sequestered, i.e. locked up for long periods, as biochar. The process thus is carbon-negative since atmospheric carbon has been locked into the soil. Biochar is rich in alkaline components (Ca, Mg, K), which may contribute to neutralization of soil acidity and to decreasing the solubility of phyto-toxic metals like aluminium in soils.

Sources of biochar: The best biochar source is organic waste that otherwise either is burned (generating CO2), degraded in an aerobic environment (also generating CO2), or in an anaerobic environment (generating CO2 as well as methane, CH4, an even more potent greenhouse gas (GHG)). No energy crops should be used, and no forest should be cut to generate biochar. An example of a promising source of biochar in Indonesia is rice husk and rice straw, of which 20 and 60 million tons, respectively, are produced annually. Currently there is no other use for these low-nutrition materials than burning and marginal soil improvement with the ashes. Generating
biochar out of this raw material would yield a better soil quality enhancer and additionally it could potentially store 10-40 million tons of carbon per year, which would compensate the annual GHG emissions of Norway (50.8 mill tons of CO2 in 2009, equivalent to 14 mill tons of carbon [Norwegian Pollution Control Authority 2010]).


WP1: Screening of soil-biochar combinations

Responsible: Dr. Neneng, Indonesian Soil Research Institute (ISRI), Bogor, Indonesia

50 acid soils from all over Indonesia will be collected and characterized. Four different biochars will be synthesized under laboratory and/or field conditions and characterized. Various amounts of the biochars will be added to the soils, and shaken for 1 week before pH, CEC, and extractable metals will be measured for the soil-biochar mixtures. In addition a long-term kinetic approach will be included with longer (up to one year) shaking times, as pyrite oxidation is expected to continue for a long time. Thus, initial alkalizing effects of biochar may gradually “fade” and this needs to be tested.
Changes in pH or absence thereof will give valuable and easily-obtained indications on the feasibility of biochar amendment for Indonesian acid soils. Changes in the various soil chemical characteristics will give clues with respect to a mechanistic explanation for the observations. We hypothesize that especially low-CEC soils will be amenable to pH increase upon biochar amendment.

WP 2: Pot and field trials including crop growth and plant uptake of organic pollutants

Reponsible: Achmad Rachman, Research Institute for Swampland Agriculture (BALITTRA), Indonesia, and Robert Bachmann, University of Kuala Lumpur, Malaysia

Three soils and two biochars are selected from WP 1. For one biochar, several pyrolysis temperatures between 400 °C and 900 °C will be tested. Pot experiments will be performed with two crops. Water-holding capacity will be determined for soils with and without biochar amendment, to study the potential effect of biochar on soil structure. Four different treatments are envisioned. Treatment 1,2 and 4 include the recommended amount of NPK fertilizer; treatment 3 includes only half (50%) of recommended fertilizer to see whether biochar reduces the amount of fertilizer needed. In addition, to one of the soils the organic pollutants pyrene  and dieldrin will be spiked to investigate the effect of biochar on pollutant uptake in plants. Soil acidity status will be monitored in the course of the pot experiments.

WP 3: Field trials for various acid soils and various climatic conditions

Responsible: NGI and UMB, Norway, ISRI and UNDP Indonesia, MARDI Malaysia

Field trials will be carried out at four locations in Indonesia and one in Malaysia. Indonesian candidate locations include Sumatra (wet climate), Kalimantan (interest of Australian and Norwegian Embassies- wet climate), West-Timor (semi-arid climate- ongoing UNDP project), East-Java (naturally acidic volcanic soil, acidification due to acid crater lake Kawah Ijen). The Malaysian test will be done at the experimental station of MARDI. The approach at the field trial will be similar to that of the pot experiments (WP 2), but without organic
pollutant spiking. The size of each individual plot will be 50-100 m2. The biochar will be generated close to the field sites using traditional methods, preferably kilns. Different biomass starting materials may be used in different places, dependent on available organic waste sources and the outcome of WP5 (biochar concepts).
After the first test, at least one additional growth cycle will be studied without amending fresh biochar, to study
the prolonged fertility effect of biochar (WP2).

WP 4: Laboratory research on biochar processes

Responsible: UMB, Norway; NGI, Norway, in collaboration with University of Oslo

The following processes will be studied:
- Nutrient availability, solubility of toxic metals and leaching will be investigated by systematic column tests with biochar-amended and non-amended soils (selected from WP1). These tests will give information on the
effect of various biochars on the binding strength and binding kinetics of the macro/micronutrients as well as deleterious Al in soil. NO3-, NH4+, K+, H2PO4-/HPO42-, Ca2+, Mg2+, SO42-, pH, Al3+ and Fe2/3+
will be measured in the eluates. Measured dissolved aluminium concentrations will be compared with
modelled values, using the mechanistic model WHAM/Model VI  and a recently developed empirical model. Also the effect of biochar on dissolved organic matter (DOM) transport, as well as biochar-DOM interactions, will be studied.
- Pesticide and organic pollutant binding to biochar will be investigated by systematic studies of several
pesticides and biochars. We will use our abovementioned POM passive samplers to carry out state-of-the-art sorption tests measuring freely dissolved concentrations.
- Stability in soil, and its influence on biochar characteristics: Selected biochars and biochar-soil combinations
will be subjected to harsh laboratory aging regimes (6 months) to mimic long-term aging. Four different types of aging will be considered:
o Chemical aging at high temperatures (60 °C and 110 °C)
o Biological aging (incubation with a microbial inoculums)
o Physical aging (freeze-thaw cycles- although not directly relevant to Indonesian soils, they do give mechanistic indications on the effect of particle abrasion)
o Field aging (samples from the field experiment- WP 3)
- After aging the samples will be subjected to the following follow-up analyses:
o Long-term chemical stability: Fourier-Transform Infrared Spectroscopy will be used to study changes in the chemical structure (functional groups) between aged and non-aged samples.
o Organic matter degradation: TOC and BC analyses will be performed as described above.
o Nutrient leaching: pH, CEC and extractable metals will be measured for aged and non-aged samples.
o PAH availability: Sorption isotherms of the isotopically labeled PAH 13C-pyrene will be analysed for aged and non-aged samples with POM passive samplers. Also availability of co-generated PAHs in biochar will be measured

WP 5: Concepts for biochar production in farmer communities: processing low-quality biomass to biochar

Responsible: UNDP, Indonesia

We propose to test several pyrolysis temperatures and several organic waste types and characterize the quality of the resulting biochar, so that optimal feedstocks and pyrolysis conditions are identified. To generate biochar for the pot test (WP2) and field tests (WP3), traditional kiln expertise is locally available. We suggest to produce biochar at the site. Alternatively, biochar can be bought from local producers. Organic waste should be used as starting material. It is envisioned to investigate the introduction of pyrolysis at three different levels, for identified target groups:

  • Households
  • Community-based
  • Entrepreneurs

WP 6: Social science: Life cycle assessment (LCA) and life cycle cost analysis (LCC)

Responsible: NGI and NTNU, Norway and UNDP, Indonesia

An initial analysis on the basis of costs for kiln, transport, labour and biomass indicates that biochar generated
on the community level will cost around 30 US$/ton. At an application rate of 10 ton/ha, this means the
investment is around 300 US$/ha. The
extra income from e.g. 50% higher rice yield  is 500-1000 US$/ha per year. Recently material flow analysis of biochar amendment was done with regard to monetary resources (cost), energy and GHG. This study dealt with the western-world situation, and did not budget the various components to an integrated LCA. We propose to carry out a similar analysis for SEAsia, but to expand the study to comprise a full LCA. The lifecycle
inventory will be based on a comparison of biochar to conventional energy production and fertilizer use. The study will use available data sources as the Ecoinvent data base adapted to local conditions.
In order to assess the aggregated environmental impact life cycle impact analysis (LCIA) will be performed at midpoint and end point level. LCIA allows weighing of the potential disadvantages (e.g. damage to ecosystem by PAHs, initial investment cost) towards the advantages (reduced GHG emissions, improved soil quality and crop yield). Life cycle cost assessment (LCC) will be performed separately addressing investments, income, and revenues through the life cycle. Resource cost from the LCIA will be integrated in this analysis.

To support the LCIA and LCC, extension workers will be used to investigate the farmer’s socio-economic
situation. NGI and NTNU, in collaboration with UNDP, will provide the questionnaires, and the Indonesian
institutes will carry out the investigation in the following manner: ISRI Bogor will use their contact network of
regional/local BPTPs, and BPTP staff will go into the field and interview the farmers.


FRIMURF Funding from Research Council of Norway


Social, environmental and agricultural scientists from universities and research institutes in Norway, Indonesia and Malaysia will collaborate. UNDP
Indonesia will lead knowledge transfer, disseminating project findings to local institutes, extension services and farmers. Three PhDs are envisioned in
Norway + Indonesia. Mutual research visits and workshops will ascertain knowledge transfer.

Published June 28, 2012 1:36 PM - Last modified Oct. 31, 2018 2:02 PM


  • Rolf David Vogt
  • Jan Mulder - UmB
  • Gerard Cornelissen - NGI
  • Annik Magerholm Fet - NTNU
  • Alex Heikens - UNDP
  • Johannes Lehmann - Cornell University
  • Anang Firmansyah - BPTP Local Agricultural Center
  • Robert Bachmann - University of Kuala Lumpur
  • Theeba Manickam - Malaysian Agricult Res and Developmt Inst MARDI
  • Åse Lekang Sørensen - DET KGL SELSKAP FOR NORGES VEL
  • Henrik Lindhjem - NINA
Detailed list of participants