1 / 5

Unraveling the Mystery of Terra Preta: Amazon's Dark Earth

Explore how indigenous tribes created fertile Terra Preta soil in the Amazon, sustaining productivity for centuries. Discover its high carbon content, sustainable fertility, and potential for reversing climate change with biochar. Learn how biochar enhances soil fertility, increases nutrient availability, and promotes plant growth, making it a vital tool for sustainable agriculture.

efrenm
Download Presentation

Unraveling the Mystery of Terra Preta: Amazon's Dark Earth

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Soil Minerals Terra Preta Terra Preta de Indio Carbon Charcoal Mystery Soil of the Amazon “dark earth” (Portuguese) How did the native Amazon tribes create these remarkably fertile and productive soils? Amazon Basin, Brazil reduced carbon • Local farmers prize terra preta • dug up and sold as potting soil • yields up to three fold as great as surrounding infertile tropical soils • sustained fertility in intensive use • 1867: Ballard S. Dunn, Confederate exile • book:Brazil: Home for Southerners • lauds high fertility of Amazon dark soil • High Carbon (SOM) content • up to 9% • compared with .5% in other soils • sometimes over 20% • one to two meters deep Terra Preta Ferralsol Conservation Grassland Minnesota How have these remarkable soils sustained their fertility and productivity for five centuries? • 1879: explorer Herbert Smith • tales of Amazon in Scribner's Monthly: • “extraordinary fecundity of cane fields… • “stalks ten feet high… big as a wrist… • "rich ‘terra preta’… best in Amazon… • “fine, dark loam… often two feet thick" • Small Patches • average: 20 hectares (50 acres) • 350 hectares (865 acres) reported • near settlements & on bluffs • embedded pottery sherds • animal & fish bones, cultural debris • Age: 800-4000 years • radio-carbon dating (charcoal) • recent research: 6000 years What can we learn from these remarkable soils to sustain soil fertility and productivity today? • High nutrient content • Calcium & Phosphorus • Nitrogen • Cation Exchange Capacity (CEC) Can this method to create tropical soils provide insights to improve temperate climate soils? • 1966:WimSombroek(Dutch;1944-2003) • published his book:Amazon Soils • first scientific study of terra preta • Made from Ferralsol or Acrisol • predominant soils in Amazon • acidic, notoriously infertile • poor nutrient capacity 1992:Sombroekpublishes his first book on terra pretafor carbon sequestration Can this method to sequester carbon in soil help us reverse global warming and climate change? • High Microbial activity • “microbial reef” • nitrogenous bacteria (nitrogen fixing) • Aerial Surveys • up to 10% of total land area • able to feed 5-10 million people 2002:Sombroek forms Terra Preta Nova to use char on farms as a carbon sink 2007:first international biocharconference click to continue click to continue click to continue click to continue click to continue click to continue

  2. Terra Preta is biochar a nutrient? Increased Fertility • higher Phosphorus & Calcium • higher Nitrogen • increased nutrient availability • lower acidity • higher pH buffering • water retention • physical structure • biological habitat (microflora & fauna) In normal soil, biochar breaks down very slowly (oxidation,weathering& digestion) – over centuries, rather than months Biochar isn’t consumed by soil life Biochar freshly made is sterile, with no biological activity – no microbes click to continue click to continue click to continue Adding only biocharto soil retards plant growth for up to two years Fertilizers must be added with biochar terra preta biochar acrisol typical Amazon soil infertile Biochar is a sponge to hold water & nutrients, and a substrate to provide habitat & housing for microbes

  3. Terra Preta Global Research 2001 biocharbenefits cation exchange capacity increased (Glaser) water-holding capacity 18%increase (Glaser) biomass growth 266%increase (Steiner 2nd year) 324% increase (Kishimoto & Sugiura) plant nitrogen uptake doubled (Steiner) farm chemical runoff reduced (Yelverton) click to continue click to continue

  4. Terra Preta Research 3-Year Field Trials Rice & Sorghum 366% 267% 881% Christoph Steiner1; W. G. Teixeira2; Johannes Lehmann3; W. Zech1 1 Institute of Soil Science, Univ. of Bayreuth, Germany 2 Embrapa Amazonia Ocidental, Manaus, Brazil 3 Dept of Crop and Soil Sciences, Cornell Univ., USA click to continue click to continue

  5. Bark Biochar & Fertilizer Terra Preta Research biochar + NPK biochar + NPK NPK control control NPK Effect of bark biocharand fertilizer on plant growth and soil properties in south Sumatra Yamato 2004 unpublished click to continue

More Related