Dr. Saran P. Sohi
- Leader: Soil Science, UKBRC
- Home Page:
Read my biochar "Perspective" in Science (23rd Nov 2012) via my publications page, on the University website (full text).
I was recruited to lead soil science research in the UK Biochar Research Centre, Edinburgh, at its inception in late 2008. I moved to Edinburgh in February 2009, and our Centre launched on April 1st.
The purpose of my work is to deliver UKBRC a sound mechanistic understanding of biochar function in soil, and gain from this the predictive capacity required to 'prescribe' biochar in ways that firstly are safe, and secondly offer the best possible results in terms of soil and crop performance at previously untested locations. The resolution and certainty of the understanding that we seek is driven by the need to assign financial value to biochar products reflecting (a) benefit to the agricultural enterprise, and (b) achievement of societal goals such as carbon storage, management of diffuse pollution, and mitigation of trace gas emission from agriculture. My work is inextricably linked to those of my colleagues who lead research into the optimising pyrolysis processes for the conversion of biomass into biochar, estimation of carbon-equivalent gains offered by pyrolysis-biochar systems, and scoping associated socio-economic issues including land-use.
The practical tools that we have established and published provide rapid assays for the screening of biochar according to five key functional properties in soil. As well as being able to establish the full (wide) range of properties exhibited by bicohar (publication forthcoming), they provide for the optimisation of the use and performance of biochar in contrasting locations and circumstances, addressing specific constraints to crop production. The dynamics of biochar properties have been investigated in this process too - and it may be possible to manipulate the timeframe over which benefits from biochar are delivered in the soil. Simultaneously, we seek to exploit the findings from our published mesocosm work, to develop products that exploit interactions found to occur between biochar and plant roots.
In undertaking directed, purposeful testing of biochar and biochar products in a range of environments (Ghana, China, Brazil, etc.), we also triangulate between laboratory work and controlled field experiments, notably the longest running UK field experiment with biochar, established in conjunction with Rothamsted Research in 2009. There we instigated an isotope-tracer experiment can hlep establish how the stabilisation of root-derived carbon (organic compounds from root exudation) are affected by the presence of biochar.
We are thus well advanced in a strategic programme of research, where a set of novel screening tools support a systematic evaluation of how alternate biomass conversion technologies and a sliding-scale for pyrolysis variables, which dictate the nature of biochar products. The knowledge that is gained here, combined with an understanding of how different plants interact with biochar (cereal crops, perennial grasses, bioenergy crops) are guiding the products that we are using in trials.
Soil Science research in UKBRC Edinburgh currently involves one post-doctoral researcher, one research scientist and a number of PhD students (some in conjunction with SRUC. formerly SAC). We link to a network of international collaboraors and guide a number of student research projects at MSc and BSc level.
My own research background is in the elucidation of soil organic matter dynamics from modelling measured dynamics of key physical fractions, the topic of my PhD and eight years post-doctoral work at Rothamsted Research, the BBSRC research institute based in Harpenden, Hertfordshire. Biochar should not be considered a distinct soil science discipline, and I seek to ensure that knowledge and experience gained from study and simulation of other recalcitrant organic matter fractions - and their interaction with more labile components - is not ignored in seeking understanding of biochar function. By way of example, existing understanding of the contrasting dynamics and interaction of soil fractions was used, in combination with simulation and isotope tracers, to assess the effect of charcoal in terra preta soils on the turnover of other soil carbon. This was my introduction to biochar soil science, and a consequence of collaborative research instigated at Cornell University, NY, where I worked in the group of Johannes Lehmann during 2005.
Relevant Research Areas:
- Biochar and international development
- Biochar and the soil ecosystem
- Biochar function
- Biochar standards
- Field experiments
- A biological perspective: Impacts of biochar on the health of cereal crops
- Ageing patterns for biochar in the field
- An assessment of the benefits and issues associated with the application of biochar to soil
- Biochar Risk Assessment Framework (BRAF)
- Biochar and plant-soil interactions
- Biochar in growing media: A sustainability and feasibility assessment
- Biochar screening toolkit
- Biochar: Socio-economic and biophysical “fit”
- Calibrating a method to compare biochar carbon stability
- Carbo-BioCrop: Carbon balance under perennial bioenergy crops
- EU COST Action
- Establishing effects of biochar on carbon dynamics in the field
- Interreg IVB North Sea Region: Climate Saving Soils
- MSc / BSc Module: Novel Strategies for Soil Carbon Storage
- Scottish Biofuel Programme
- Sustainable Urban Carbon Capture - Engineering Soils for Climate Change (SUCCESS)
- Use of biochar in management of organic amendments in grassland agriculture
- Use of biochar in phosphorus recycling and recovery
Shepherd JG, Sohi SP and Heal KV. 2016. Optimising the recovery and re-use of phosphorus from wastewater effluent for sustainable fertiliser development. Water Research DOI:10.1016/j.watres.2016.02.038
Bachmann HJ, Bucheli TD, Dieguez-Alonso A, Fabbri D, Knicker HE, Schmidt H-P, Ulbricht A, Becker R, Buscaroli A, Buerge D, Cross A, Dickinson D [...] Masek O, Mumme J, Carmona M, Calvelo R, Rees F, Rombolà AG, de la Rosa JM, Sakrabani R, Sohi SP, Soja G, Valagussa M, Verheijen FGA, Franz F. 2016. Toward the standardization of biochar analysis: The COST Action TD1107 interlaboratory comparison. Journal of Agricultural and Food Chemistry 64: 513–527
Han Y, Cao X, Ouyang X, Sohi SP, Chen J. 2015. Adsorption kinetics of magnetic biochar derived from peanut hull on removal of Cr (VI) from aqueous solution: Effects of production conditions and particle size. Chemosphere 145: 336–341
McClean GJ, Meredith W, Cross A, Heal KV, Bending GD, Sohi SP. 2015. The priming potential of environmentally weathered pyrogenic carbon during land-use transition. GCB Bioenergy doi:10.1111/gcbb.12293
Sohi, S.P., McDonagh, J., Novak, J., Wu, W., Miu, L.-M. 2015. Biochar Systems and System fit. Biochar for Environmental Management (Eds Lehmann, J., Joseph, S.), 2nd Edition, Routledge, London.
Crombie, K., Mašek, O., Cross, A., Sohi, S.P.. 2014. Biochar–synergies and trade‐offs between soil enhancing properties and C sequestration potential. GCB Bioenergy doi: 10.1111/gcbb.12213
Angst, T.E., Six, J., Reay, D.S., Sohi, S.P. (2014) Impact of pine chip biochar on trace greenhouse gas emissions and soil nutrient dynamics in an annual ryegrass system in California. Agroecosystems and the Environment 191:17-26
Verheijen, F.G.A., Graber, E.R., Ameloot, N., Bastos, A.C., Sohi, S.P., Knicker, H. (2014) Biochars in soils: new insights and emerging research needs. European Journal of Soil Science 65:22–27
Jeffery, S., Bezemer, T.M., Cornellisen, G., Kuyper, T.W. Lehmann, J., Mommer, L., Sohi, S.P., Van De Voorde, T.F.J., Wardle, D.A., Van Groenigen, J.W. (2013) The way forward in biochar research: targeting trade-offs between the potential wins. GCB Bioenergy doi:10.1111/gcbb.12132
Prendergast-Miller, M., Duvall, M., Sohi, S.P. (2013) Biochar−root interactions are mediated by biochar nutrient content and biochar impacts on soil nutrient availability. European Journal of Soil Science 65:173-185
Angst, T.E. (2013) Evaluating the Impacts of Biochar on the Fate and Dynamics of Dairy Manure in Agricultural Soil. PhD thesis, University of Edinburgh, School of GeoSciences, 237pp.
Carter, S., Shackley, S., Sohi, S.P., Suy, T.B. and Haefele (2013) The impact of biochar application on soil properties and plant growth of pot grown lettuce (Lactuca sativa) and cabbage (Brassica chinensis). Agronomy, 3:408-418
Sohi, S.P., Gaunt J.L., Atwood, J. (2013) Biochar in growing media: A sustainability and feasibility assessment. A project commissioned for the Sustainable Growing Media Task Force. Defra project SP1213. Defra, London, 84pp
Angst, T.E., Patterson, C.J., Reay, D.S., Anderson, P., Peshkur, T.A., Sohi, S.P. (2013) Biochar diminishes nitrous oxide and nitrate leaching from diverse nutrient sources. Journal of Environmental Quality 42:672-82
Angst, T.E., Sohi, S.P. (2013) Establishing release dynamics for plant nutrients from biochar, GCB Bioenergy, 5:221-226
Cross, A., Sohi, S.P. (2013) A method for screening the relative long-term stability of biochar, GCB Bioenergy, 5:215-220
Sohi, S.P. (2013) Pyrolysis bioenergy with biochar production – greater carbon abatement and benefits to soil, GCB Bioenergy, 5:i-iii
Crombie, K., Mašek, O., Sohi, S.P.. Brownsort, P., Cross, A. (2013) The effect of pyrolysis conditions on biochar stability as determined by three methods, GCB Bioenergy, 5:122-131
Sohi, S.P. (2012) Carbon storage with benefits, Science, 338: 1034-1035
Shackley, S., Carter, S., Knowles, T., Middelink, E., Haefele, S., Sohi, S., Cross, A., Haszeldine, S. (2012), Sustainable gasification-biochar systems? A case-study of rice-husk gasification in Cambodia, Part I: context, chemical properties, environmental and health and safety issues, Energy Policy, 42: 49-58.
Shackley, S., Sohi, S.P., Ibarrola, R.E., Hammond, J., Masek, O., Brownsort, P., Cross, A., Prendergast-Miller, M., Haszeldine, S. 2012, Biochar, Tool for Climate Change Mitigation and Soil Management. In: R Meyers (ed.), Encyclopedia of Sustainability Science and Technology, Springer Verlag, New York, pp. 913-961 http://dx.doi.org/10.1007/978-1-4614-5770-1_6
Prendergast-Miller M.T., Duvall, M., Sohi, S.P. (2011) Localisation of nitrate in the rhizosphere of biochar-amended soils. Soil Biology and Biochemistry 43: 2243-2246
Mašek, O., Brownsort, P., Cross, A., & Sohi, S. (2011). Influence of production conditions on the yield and environmental stability of biochar. Fuel. doi:10.1016/j.fuel.2011.08.044
Cross, A., Sohi, S.P. (2011) The priming potential of biochar products in relation to labile carbon contents and soil
organic matter status, Soil Biology & Biochemistry, 43: 2127-2134
Shackley S, Carter S, Sims K and Sohi S P 2011 Expert perceptions of the role of biochar as a carbon abatement option with ancillary agronomic and soil-related benefits, Energy & Environment 22(3): 167-187
Hammond J, Shackley S, Sohi S P and Brownsort PA 2011. Prospective life cycle carbon abatement for pyrolysis biochar systems in the UK. Energy Policy 39, 2646-2655.
Oliver, I., Cross, A., Searl, A., Shackley, S., Smith, C., Sohi, S. The State of Scotland's Soil: Emerging Issues, SEPA, 2011
Karve P, Shackley S, Carter S, Anderson P, Prabunhe R, Cross A, Haszeldine S, Haefele S, Knowles T, Field J, Tanger P (2011), Biochar for Carbon Reduction, Sustainable Agriculture and Soil Management (BIOCHARM). A Report for the APN (Asia Pacific Network for Climate Change Research).
Ahmed SJ, Hammond J, Rodrigo IE, Shackley SJ, Sohi SP and Haszeldine RS 2010. The potential of biochar deployment in Scotland: A preliminary assessment , UKBRC working paper 7.
Prendergast-Miller M and Sohi SP 2010. Investigating biochar impacts on plant roots and root carbon. Poster presented in the Organic Matter Stabilization and Ecosystem Functions session at Soil Organic Matter Conference, Cote d'Azur, France (Sept. 2010).
Hammond J, Shackley SJ, Sohi SP and Brownsort PA 2010. Life Cycle Analysis for Pyrolysis Biochar Systems in the UK. Poster presented in the 3rd Annual conference of International Biochar Initiative (IBI), Rio De Janeiro, Brazil.
Prendergast-Miller, M. and Sohi, S.P. (2010) Charcoal effects on plant roots: implications for biochar. Poster presented at the 2nd UKBRC Conference, Rothamsted, UK.
Shackley SJ and Sohi SP (eds) 2010. An assessment of the benefits and issues associated with the application of biochar to soil. Department for Environment, Food and Rural Affairs, London, UK.
Sohi SP, Lopez-Capel E, Bol R & Krull E. 2010. A review of biochar and its use and function in soil. Advances in Agronomy 105: 47-82
Lehmann J, Czimczik CI, Laird D & Sohi SP. 2009. Stability of biochar in soil ecosystems. In: CJ Lehmann and S Joseph (Eds), Biochar for Environmental Management: Science and Technology, Earthscan, London pp183-205
Sohi SP, Shackley SJ, Haszeldine RS, Manning D and Mašek O 2009. Biochar, reducing and removing CO2 while improving soils:A significant and sustainable response to climate change. Evidence submitted to the Royal Society Geo-engineering Climate Enquiry, UKBRC Working Paper 2
Sohi SP, Shackley SJ, Mandy M, Pratt K, Lopez-Capel E,Haszeldine RS, Gaunt J, Masek O, Manning D, Cook J and Carter S 2009. Biochar: An Emerging Technology for Climate Change Mitigation?, Workshop proceedings, UKBRC Working Paper 1
Liang B, Lehmann J, Sohi SP, Thies JE, O’Neill B, Trujillo L, Gaunt JL, Solomon D, Grossman J, Neves EG, & Luizão FJ. 2010. Black carbon affects the cycling of non-black carbon in soil. Organic Geochemistry 41: 206–213
Lehmann J, Skjemstad J, Sohi SP, Carter J, Barson M, Falloon P, Coleman K, Woodbury P & Krull E. 2008. Australian climate–carbon cycle feedback reduced by soil black carbon. Nature Geoscience 1:832-835
Lehmann J & Sohi SP. 2008. Comment on “fire-derived charcoal causes loss of forest humus”. Science 321:1295c