Biochar as an adaptation strategy for climate change

Biochar is the carbon-rich solid product that remains following the pyrolysis of organic agricultural waste. When mixed in to soil, biochar: 1) remains stable, and thus its carbon is sequestered (greenhouse gas (GHG) mitigation), 2) suppresses emissions of other GHGs, nitrous oxide and methane (GHG mitigation), 3) utilises agricultural waste and generates energy (climate change adaptation) 4) increases soil fertility of degraded tropical lands potentially increasing harvest yields (climate change adaptation and poverty reduction) and 5) is able to strongly sorb contaminants thus remediating soil. In this project implementation and socio-economic issues of the application of biochar to degraded Indonesian soils was investigated. The mechanisms of how and whether biochar is able to improve crop yield were investigated using controlled field trials on a strongly acidic soil. A substantial increase in yield was observed for maize when two different biochars were amended at two different doses. A liming effect and a nutrient addition effect, mainly of potassium, were observed to be responsible for the increase in yield. More basic fundamental biochar related research was carried out through several laboratory-based experiments. Several problematic organic and inorganic pollutants were chosen as model compounds in order to investigate binding to biochar. The sorption of the legacy pesticides hexachlorocyclohexanes (HCH) to several biochars was determined, with differences arising due to isomer stereochemistry and biochar type. Per- and polyfluoroalkyl substances (PFAS) and heavy metal contaminated soils were treated with designer biochars that were intended for use as remediation sorbents. Activation and iron enrichment had a large positive effect of remediation efficacy for the PFAS and heavy metal contaminated soils, respectively. Biochar amendment to soil in order to sequester PCBs and reduce bioavailability to passive samplers and plants was successfully demonstrated. Parallel experiments were carried out in order to investigate the sorption, bioavailability, bioaccessibility and ecotoxicity of pyrene, PCB 52, and p,p´-DDE in polluted soil. Biochar was able to reduce bioaccessibility and ecotoxicity through a strong sorption. Social research identified the barriers and opportunities for implementation of biochar in Indonesia and a life cycle assessment comparing the use of biochar to conventional energy production and farming. Economic factors were addressed via a cost-benefit analysis to assess whether different biochar technologies are favourable compared to composting considering social benefits compared to costs. The project was a collaboration between the Norwegian Geotechnical Institute (NGI), the Norwegian University of Life Sciences (NMBU), the Technical University Trondheim, Norway (NTNU), Menon Economics, the Danish Technical University (DTU), The United Nations development program (UNDP) and the Indonesian Soil Research Institute (ISRI). Several spin-off projects resulted from the work. The first of which was an Indonesian contribution to the Biochar for Sustainable Soils project, where around thirty farmers were trained in biochar making in two districts on Java and Sumatra. The second was the use of biochar in Brazilian soils to improve pasture crop growth.

In Indonesia, working at the grass root level meant that the research carried out in the project can be used directly by the farmers who need methods to improve their crop productivity. This will in turn have a large positive effect on the general wellbeing of people living in Indonesia. The farmers in Indonesia have gained new skills and knowledge related to the use of biochar to improve the quality of their soils. It is hoped that these results will be used on a national level to improve livelihood. The Norwegian team has been successful in increasing their mechanistic knowledge related to the reason behind the increased crop growth in Indonesia. This objective was achieved via controlled field trials. In addition the Norwegian team has made significant progress towards showing that biochar can be used as a material for the remediation of contaminated soil and water for legacy hydrophobic organic contaminants. This could lead to the establishment of a new market in this area.

Biochar is the carbon-rich charcoal produced from pyrolysis of organic agricultural waste. When mixed in to soil, biochar: 1) remains stable, and thus its carbon is sequestered (GHG mitigation), 2) suppresses emissions of other GHG, nitrous oxide and methane (GHG mitigation), 3) utilises agricultural waste and generates energy (climate change adaptation) and 4) increases soil fertility of degraded tropical lands potentially increasing harvest yields (climate change adaptation and poverty reduction). In this project we will investigate implementation and socio-economic issues as well as energy aspects around biochar technologies. To begin with and to provide a fundamental basis, we will look at mechanisms behind biochar's GHG mitigation potential as well as its beneficial effect on soil fertility. In order to assure implementation can be investigated we will extend our collaborations with UNDP Indonesia. Social research aspects will look at biochar generation concepts identifying barriers and opportunities and a life cycle assessment comparing the use of biochar to conventional energy production and farming. Socio-economic factors will be addressed via a cost-benefit analysis to assess which biochar technologies and use options give the highest social benefits compared to costs. Potential risks of unintended impacts of biochar use will also be addressed. Social, environmental and agricultural scientists from universities and research institutes in Norway and Indonesia will work together. UNDP will lead knowledge transfer to the grass root level (farmers). The proposed research will allow a significant scientific and mechanistic depth, highly benefitting from current smaller biochar projects the applicants are running in Zambia and Brazil (Norad), Uganda and Tanzania