Terra Preta (which means "dark soil" in Portuguese), refers to expanses of very dark soils found in the Amazon Basin.
This lost secret from the Amazon is now being studied extensively by thousands of scientists and a multitude of universities around the globe. Several articles have been written about this sustainable agricultural system that allowed millions of people to thrive on some of the world's worst soils. They study this subject matter under the scientific term biochar, instead of terra preta research. Dr. Lehmann of Cornell University has explained that these soils were formed due to large applications of charred biomass and "These applications were most likely a result of both habitation activities and deliberate soil application by Amerindian populations before the arrival of Europeans (Erickson et al. 2003). Large amounts of bio-char derived carbon stocks remain in these soils today, hundreds and thousands of years after they were abandoned."
Dr. Lehmann also explains that..." The application of bio-char, or biomass-derived black carbon (C)) to soil is proposed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems. Apart from positive effects in both reducing emissions and increasing the sequestration of greenhouse gases, the production of bio-char and its application to soil will deliver immediate benefits through improved soil fertility and increased crop production. Conversion of biomass C to bio-char C leads to sequestration of about 50% of the initial C... Bio-char soil management systems can deliver tradable C emissions reduction, and C sequestered is easily accountable, and verifiable.
Glaser, B., Lehmann, J. and Zech, W. 2002. "Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal - a review", Biology and Fertility of Soils 35 , 219-230.
Hansen, James, Makiko Sato, Pushker Kharecha, David Beerling, Valerie Masson-Delmotte, Mark Pagani, Maureen Raymo, Dana L. Royer, James C. Zachos, "Target Atmospheric CO2: Where Should Humanity Aim?" , In press. [Supporting materials ]. [This key paper by leading climate scientist James Hansen explicitly mentions biochar as an important strategy needed to reduce atmospheric CO2 levels from the current 387ppm to 350ppm].
Lehmann, J. 2007. "A handful of carbon", Nature 447, 143-144.
Lehmann, .J, Gaunt, J. and Rondon, M. 2006. "Bio-char sequestration in terrestrial ecosystems – a review", Mitigation and Adaptation Strategies for Global Change 11, 403-427.
Lehmann J. 2007. "Bio-energy in the black." Frontiers in Ecology and the Environment 5, 381-387.
Lehmann J. and Rondon M. 2006. "Bio-char soil management on highly weathered soils in the humid tropics". In Uphoff N. (ed.) Biological Approaches to Sustainable Soil Systems. CRC Press, Boca Raton , FL. pp.517-530.
Lehmann, J., da Silva Jr., J.P., Steiner, C., Nehls, T., Zech, W. and Glaser, B. 2003. "Nutrient availability and leaching in an archaeological Anthrosol and a Ferralsol of the Central Amazon basin: fertilizer, manure and charcoal amendments", Plant and Soil 249 , 343-357.
Liang, B. , Lehmann, J., Solomon, D., Kinyangi, J., Grossman, J., O'Neill, B., Skjemstad, J.O., Thies, J., Luizão, F.J., Petersen, J. and Neves, E.G. 2006. "Black carbon increases cation exchange capacity in soils", Soil Science Society of America Journal 70: 1719-1730.
Marris, E. 2006. "Black is the new green", Nature 442: 624-626.
Mikan, C.J. and Abrams, M.D. 1995. "Altered forest composition and soil properties of historic charcoal hearths in southeastern Pennsylvania", Canadian Journal of Forestry Research 25, 687-696.
Okimori, Y., Ogawa, M. and Takahashi, F. 2003. "Potential of CO2 emission reductions by carbonizing biomass waste from industrial tree plantation in south Sumatra , Indonesia", Mitigation and Adaptation Strategies for Global Change 8 , 261-280.
Pessenda, L.C.R., Gouveia, S.E.M. and Aravena, R. 2001. "Radiocarbon dating of total soil organic matter and humin fraction and its comparison with 14 C ages of fossil charcoal", Radiocarbon 43 , 595-601.
Schmidt, M.W.I. and Noack, A.G. 2000. ‘Black carbon in soils and sediments: analysis, distribution, implications, and current challenges', Global Biogeochemical Cycles 14 , 777-794.
Seifritz, W. 1993. "Should we store carbon in charcoal?", International Journal of Hydrogen Energy 18 , 405-407.
Shindo, H. 1991. "Elementary composition, humus composition, and decomposition in soil of charred grassland plants", Soil Science and Plant Nutrition 37 , 651-657.
Sombroek, W., Nachtergaele, F.O. and Hebel, A. 1993. "Amounts, dynamics and sequestering of carbon in tropical and subtropical soils", Ambio 22, 417-426.
Steiner, C., Teixeira, W. G., Lehmann J., Nehls, T., Vasconcelos de Macêdo, J. L. V., Blum, W. E. H. and Zech, W. 2007. "Long term effects of manure, charcoal and mineral fertilization on crop production and fertility on a highly weathered Central Amazonian upland soil", Plant and Soil. 291, 275-290.
Warnock, D.D., Lehmann, J., Kuyper, T.W. and Rillig, M.C. 2007. "Mycorrhizal responses to biochar in soil – concepts and mechanisms", Plant and Soil 300, 9-20.
Woods, William I., Newton P. S. Falcão, and Wenceslau G. Teixeira. 2006. "Biochar Trials aim to enrich soil for smallholders". Nature 443:144.
Woolf, Dominic. "Biochar as a Soil Amendment - A review of the Environmental Implications" , January 2008, Swansea University.
Yaman, S. 2004. "Pyrolysis of biomass to produce fuels and chemical feedstocks", Energy Conversion and Management 45 , 651-671.
Yanai, Y., Toyota, K. and Okazani, M. 2007. "Effects of charcoal addition on N2O emissions from soil resulting from rewetting air-dried soil in short-term laboratory experiments." Soil Science and Plant Nutrition 53, 181-188.
International Rice Research Institute: "Black Soil, Green Rice", Rice Today (April-June 2007).
Lehmann, Johannes; Kern, Dirse C.; Glaser, Bruno and Woods, William I. Amazonian Dark Earths: Origin, Properties, Management. Springer, January 2004, 523 pages.
Steiner, Christoph. Slash and Char as Alternative to Slash and Burn - soil charcoal amendments maintain soil fertility and establish a carbon sink . Cuvillier Verlag, Bayreuth. December 2007. [Summary].
Conferences and symposia
Biochar at the UNCCD Side event at the United Nations Climate Change Conference Bali, 13 December 2007
Goodspeed Kopolo; UNCCD (presentation). Harnessing the results in a sustainable loop that enhances adaptation to and mitigation of climate change effort in synergistic ways that also help achieve the Millennium Development Goals.
Prof. Dr. Wolfgang Zech; University of Bayreuth (presentation). An overview of naturally occurring soil carbon, its depletion and how to redress this trend. The origin of Terra Preta soils and how their replication could have the most significant impact on the achievement of the targets of the World Food Summit.
Dr. Christoph Steiner; University of Georgia (presentation). Soil charcoal amendments: maintaining soil fertility, reducing soil vulnerability, and establishing a carbon sink.
Symposium at the Annual Meeting of the American Academy for the Advancement of Science (AAAS) on "Amazonian Dark Earths - New Discoveries" in February 2006.
Symposium and Workshop at the World Congress of Soil Science (WCSS) "Amazonian Dark Earth Soils (Terra Preta and Terra Preta Nova): A Tribute to Wim Sombroek" and Workshop "Bio-char as a Soil Amendment - Research Priorities and Challenges" in July 2006.
On April 29-May 2, 2007, the International Agri-char Initiative (IAI), founded at the WCSS in 2006, held its first international meeting in Terrigal, Australia. Read more about it under http://www.iaiconference.org/. Information about the presentations can be found here.
ABC Science TV: Catalyst, 2007: Agrichar - A Solution to Climate Change? [Streaming video, or Youtube ]. Presents an overview of biochar research, trials and potential in Australia. The film also shows a pyrolysis technology that yields both char and syngas. The syngas powers the pyrolysis process, excess is used for electricity generation. [Transcript here].
BBC Horizon documentary, 2002. "The Secret of El Dorado." 46 minutes. Explores the science behind terra preta soils. Near the end of the programme, the makers show contemporary research and trials with biochar.
Beyond Zero Emissions: Drawing down carbon - Johannes Lehmann of Cornell University talks Biochar. [Podcast: mp3 format, 28 minutes]: Professor Lehmann explains the concept and says we can and should start to implement it right away because it allows us to remove CO2 from the atmosphere.
Beyond Zero Emissions: Australian of the Year 2007, Tim Flannery talks biochar and why we need to move into the renewable age. [Podcast: mp3 format, 26 minutes]: Professor Tim Flannery explains why Terra Preta (Amazonian Dark Earths) and biochar are so important in the climate fight. The potential of the concept is discussed as well as its costs. Flannery is a paleontologist and conservationist, and former director of the South Australia Museum. He is a professor at Macquarie University (Sydney) and was a professor of Australian Studies at Harvard University.
Beyond Zero Emissions: More Carbon for Soils, More Carbon for Crops - Carbon Negative Farming with Biochar . [Podcast: mp3 format, 28 minutes]: Dr Lucas Van Zwieten, senior research scientist of the NSW Department of Primary Industries (DPI), Australia, discusses biochar trials. In a latest series of trials he found a doubling of biomass and grain yields for sweet corn and 'very significant' differences in corn production. Likewise, some biochars have shown "very, very significant reductions in nitrous oxide emissions from the soil; between five- and ten-fold reductions in nitrous oxide emissions." Van Zwieten is currently conducting large scale tests with biochar on sugarcane.
International Biochar Initiative
eGenesis Industries : TERRA-PRETA-BIOCHAR