Mystery Soil of the AmazonMystery Soil of the AmazonAmazon Basin, BrazilAmazon Basin, Brazil

Soil MineralsSoil Minerals

Climate ChangeConfronting

OxisolOxisolpredominant Amazon soilspredominant Amazon soils

acidicacidicnotoriously infertilenotoriously infertile

very low carbonvery low carbonpoor nutrient capacitypoor nutrient capacity

Terra PretaTerra Preta

Local farmers prize Local farmers prize Terra PretaTerra Preta• yields three times greater than yields three times greater than

adjacent infertile tropical soilsadjacent infertile tropical soils• sustained fertility in intensive usesustained fertility in intensive use• dug up and sold as potting soildug up and sold as potting soil

““dark earth” dark earth” ((PortuguesePortuguese))

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Small PatchesSmall Patches average: 20 hectares (50 acres)average: 20 hectares (50 acres) up to 350 hectares (865 acres)up to 350 hectares (865 acres) near settlements & on bluffsnear settlements & on bluffs cultural debriscultural debrisanimal & fish bonesanimal & fish bones embedded pottery sherdsembedded pottery sherds

AgeAge800 - 4000 years800 - 4000 yearsradio-carbon dating (charcoal)radio-carbon dating (charcoal)recent research: 6000 yearsrecent research: 6000 years

““dark earth” dark earth” ((PortuguesePortuguese))

Amazon Basin, BrazilAmazon Basin, Brazil

Soil MineralsSoil Minerals

Aerial SurveysAerial Surveys10% of total land area10% of total land areaable to feed 5-10 million peopleable to feed 5-10 million people

Terra PretaTerra Preta

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High Microbial ActivityHigh Microbial Activity““microbial reef”microbial reef”Soil Food WebSoil Food WebHigh diversity, high stabilityHigh diversity, high stabilityNitrogen-fixing bacteriaNitrogen-fixing bacteria

High NutrientsHigh NutrientsCation Exchange Capacity (CEC)Cation Exchange Capacity (CEC)Calcium (+)Calcium (+)Phosphorus (-)Phosphorus (-)Nitrogen (+ / -)Nitrogen (+ / -)

High CarbonHigh Carbonup to 9%up to 9%compared with .5% in other soilscompared with .5% in other soilssometimes over 20%sometimes over 20%two to six feet deeptwo to six feet deepmost carbon is charcoalmost carbon is charcoal

““dark earth” dark earth” ((PortuguesePortuguese))

Amazon Basin, BrazilAmazon Basin, BrazilCharcoalCharcoal

Soil MineralsSoil Minerals

reduced carbonreduced carbon

Terra PretaTerra Preta

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How did Amazon natives create these How did Amazon natives create these remarkably fertile and productive soils?remarkably fertile and productive soils?

How did these soils sustain their How did these soils sustain their remarkable productivity for five centuries?remarkable productivity for five centuries?

What can we learn from these soils to What can we learn from these soils to sustain soil productivity today?sustain soil productivity today?

Can this way to create these tropical soils Can this way to create these tropical soils give insights to improve temperate soils?give insights to improve temperate soils?

Can this sequester carbon in soilCan this sequester carbon in soilto help reverse global warming?to help reverse global warming?

CharcoalCharcoalSoil MineralsSoil Minerals

reduced carbonreduced carbon

Terra PretaTerra Preta

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suck COsuck CO22

fixed intofixed into

transform intotransform into

boost soil fertilityboost soil fertility

photosynthesisphotosynthesis

restore restore Soil BiologySoil Biologygrow moregrow more

pyrolysispyrolysis

inoculateinoculate

out of Earth’s atmosphereout of Earth’s atmosphere

CarbohydratesCarbohydratesplant biomassplant biomass

BiocharBiocharsequestered carbonsequestered carbon

positive feedback

loop

In tropical Amazon,In tropical Amazon,replacing replacing slash & burnslash & burn

with with slash & charslash & charcan create can create sustainable soil fertilitysustainable soil fertility

initiateinitiate permanent agriculture permanent agriculture end end rainforest destructionrainforest destruction

Organic FarmerOrganic FarmerOrleans, MassachusettsOrleans, Massachusetts

Robert WellsRobert Wells

ConfrontingConfrontingClimate ChangeClimate Change

Can this work Can this work in our “temperate” climate?in our “temperate” climate?

our question is:our question is:

Any strategy to increase arable land,Any strategy to increase arable land,and improve productivity & yieldand improve productivity & yield

on existing arable landon existing arable landshould receive research priority.should receive research priority.

Terra PretaTerra Pretaheavy Amazon clayCape Cod beach sand

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suck COsuck CO22

fixed intofixed into

transform intotransform into

boost soil fertilityboost soil fertility

photosynthesisphotosynthesis

restorerestore Soil BiologySoil Biologygrow moregrow more

pyrolysispyrolysis

inoculateinoculate

out of Earth’s atmosphereout of Earth’s atmosphere

CarbohydratesCarbohydratesplant biomassplant biomass

BiocharBiocharsequestered carbonsequestered carbon

positive positive feedbackfeedback

looploop

Can this work Can this work in our “temperate” zone?in our “temperate” zone?

our question is:our question is:

click tocontinue

ConfrontingConfrontingClimate ChangeClimate Change