Terra Preta recipes are not creating Terra Preta: What is missing ?

Wenceslau TeixeiraEmbrapa Solos

Manaus – Brazil

Assumptions

Terra Preta in this talk means - the antropic horizons found in the Amazon -

called - Terra Preta de Índio (Amazonian Dark Earths)

- The (receipts) properties that we are trying to mimic is mainly to improve agronomic quality of

soils

Dark soil horizons Terras Pretas

Tipically A horizons darkened by organic substances

Classified by

Color (low values > 4 - typically 3)Carbon content (organic)

Width Concentration of exchangeable bases

Phosphorus levels

Terra Pretas

• Alquimia dos microorganismos ?

X

Melanização de horizonte enriquecido

(o horizonte AB ou BA é o mais rico em P e outros

nutrientes em muitos perfis)

In Brazil Antropic A horizons are found in the soilArgissolos (Acrisols)Latossolos (Ferralsols)Espodossolos (Spodosols)Neossolos Flúvicos (Neossolos Quartzarenicos (Aluvisols)Gleissolos (Gleysols)Plintossolos (Plintosols)

Contudo deve atender o critério de > 250 ppm de P2O5 (ácido cítrico)

The european Terras Pretas

Plaggic Anthrossols

must have a plaggic horizon > 50 cm depth, containing artefacts, having texture of sand to loam. Munsell colours with values 4 or less (moist) or 5 (dry) and chroma of 2 or less (moist). Carbono is 0.6% or more and P2O5 (citric acid) > 250 mg kg-1.

Until know is not proved to have plaggen epipedons in the Amazon

Examples of Plaggic An throsols of Oldenburg, Germany - Source: Luise Giani - Oldemburg Univsität

Sambaquis Frequently they contain burial remains covered by dark soil and rare lithic artifacts.

The sambaquis are believed to have been intentionally built by a population that inhabited the region for over 6000 years.

Frequently the sambaquis show dark horizons but not only in the top horizon, but also dispersed in a complex stratigraphic sequence. The mechanism of stabilization of the carbon in the sambaquis is not clear, but probably is involved in the heating of organic material (pyrolysis) and large amounts of available calcium from the shells. Those horizon resembling, at least in some aspects, similar process involved in the formation of the A chernozems (from a geological parent material rich in carbonates).

Dark layers in an sambaqui. Source Paulo De Blasis.

Sambaquis (antropic shell monds)

The sambaquis are found mainly along the Brazilian coast and are predominantly constituted of piled up mollusk shells and sediments in very complex stratigraphic configurations.

Dark horizon in the shell mounds - SantaCatarina

Fluvial Sambaqui - São Paulo

Photo: Claudia Plens - MAE

TERRA PRETA DE ÍNDIO

TPI – proxima ao rio Urubu

TPI – próxima ao Rio Preto da EvaLatossolo Amarelo - Manaus

Terra Preta de Índio in the fertile

floodplains

Costa do Marrecão - Manacapuru

Terra Preta de Índio

The profiles are crazy

- The age are not like normal soil

profile in antropic horizons

Probably P leaching (AB / BA are the

richest ones)

P change from P-Ca / P-Fe and F-Al

Iron is reduced (Total analyses)

How old are TPI profiles ?

CHARCOAL - BIOCHAR• Adding biochar to the soil - for what ?

• - to stock carbon in a recalcitrant form

• - to create charges (CEC / AEC) ?

• - to create soil fertility ?

- to create habitat to microorganisms ?

• - as source of carbon to microorganism ?

• - to improve water holding capacity ?

• to improve fertilizers efficiency

• to reduce pesticides effects

• to improve yields

Investigating Antropic soil horizons

Dealing with high soil variability in small scale

horizontaly

vertically

Classical statistical approach

Geostatistical approach

Different sources of nutrients enhanced variability

Vegetal residues

Trunks, bunches, leaves (palm leaves)

“Paú –system ”

Charcoal and ashes

Animal residues

Bones,

fish bones,

blood and skins

Manure

Others sources

- human bodies

- feaces and urine

- mineral sources (clay material for ceramic , rock (lithic artifacts),

Fonte: Woods W.

Fonte: Lima H.

Investigating Antropic soil horizons

Dealing with high soil variability in small scale

horizontaly

vertically

Classical statistical approach

Geostatistical approach

Charcoal - Biochar

What is it ?Agronomical effects ?

15 years of field investigation in the Central Amazon

- Zech, Glaser, Lehmann, Steiner, Teixeira,Arruda, Falcão

TERRA PRETA MEETING - 2002

Charcoal composition

Ash composition

Physical properties changed by using charcoal applications

- Dispersed clay- Enhance soil water retention- Enhance specific soil surface

- Agregation and habitat for soil biota

Which caracteristics of TPI we want o mimic in our new TP sites ?

Soil fertility ?Soil resilience ?

Soil carbon stocks ?

What is the definition of soil fertility ?

Soil fertility in the tropics

Not only add fertilizers (mineral or organic) but also to enhance the soil capacity to hold them

Enhance Cation Exchange CapacityK+, Na+, Ca++, Mg++, Anion Exchange Capacity

SO4--, HPO4-, NO3-

The Panema Hypothesis -

TPI Cultural artefact (not intentionally done for agriculture) but it was done not create by human living

The Project Caldeirão – modeling the formation and evolution of Amazonian Dark Earths

MP 2 – Projeto 02.09.01.014.00.00 - As Terras Pretas de Índio da Amazônia: o entendimento de sua formação e evolução. I

The Caldeirão Research Station – TPI site

Solimões river

Floodplains

Small anfitheather

Fonte: Teixeira

How to Modeling dynamic and complexes processes as TPI formation and evolution ?

Multidiscisplanary dataHow to integrate those data in a model to fit a complex process

like

TPI formation and evolution

One possibility is to use

General systems theory

The receipt will depend of taste of the gasts

Our gasts are plant roots

Rice, Cacao - likes soupsGuarana - Papaia - doesnt like soups

Charcoal is a not the main course

The main course will be nutrients

Not so many salt not so much only the necessary !

Genereal systems theory - approach

Thank you for your attention

Wenceslau TeixeiraEmbrapa Solos

E-mail: wenceslau@cnps.embrapa.brTel: 55 (21) 21794583