Christian HARTMANNPascal JOUQUET

Michel GRIMALDI

UMR BIOEMCO (becoming ‘IEES Paris’) Team ‘BIOPHYS’

Soil Bio-physical Structural Management

Before explaining why we want to use biological activity to mange I would like to present the context: 1. our UMR : mixed research unit2. our regional partnership in South-East Asia…

UMR = a scientific question…

i i EESEES Paris Paris

Biophys team

Main focuses:

In tropical landscapes subject to intense changes in land use

1.Describing biophysical processes that structure soil (aggregation vs. disaggregation)

2.Evaluating effects of changes in biophysical processes on soil ecosystem services (primary production; regulation of water fluxes and soil erosion; regulation of climate; …)

i i EES EES ParisParis

Institute of Ecology and Environmental Sciences - Paris

Biophys team

Axis 1: Landscape and soil dynamics as a result of LAND-USE changes

Field observations in long-term observatories

• Drivers of land-use changes• Agricultural practices effects on:– vegetal cover diversity and fragmentation;– biodiversity of plants and soil fauna;– soil surface conditions: crusting, infiltrability, erodibility.

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LAND USES Changes

Vegetal mosaicBiodiversity

Soil surface states

AXIS1

Institute of Ecology and Environmental Sciences - Paris

Biophys team

Axis 2: Biophysical PROCESSES of SOIL structuration and resulting hydro-structural properties

Field and laboratory experimentations

Analysis of interactions between soil engineers (roots and macroinvertebrates) and soil composition, structureand hydrodynamic properties,at soil horizon andfunctional domains rhizosphere, drilosphere,…) scales.

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Shrinkage curve

Soil engineers

PRO CES SES

Soil composition and structure

LAND USES Changes

Soilhydro-structural

properties

AXIS1

AXIS2

Institute of Ecology and Environmental Sciences - Paris

Laboratoire Géosciences Environnement Toulouse

BIOEMCO; IRD makes the link with local partners that have the willing of improving the well being ofpeople

Et au sein de l’UMR on a un le groupe biophys…. Maintaing soil ressources…

-Knowledge transfer (academic research, lab, instruments…)

-Well being of people and ressources of the country

PARTNERSHIP ==> OUTCOME FOR THE COUNTRY

Laos: NAFRI & NUOL

Thailand: LDD & KKU

IRD ==> partnership (national partners)

-Knowledge transfer (academic research, lab, instruments…)

-Well being of people and ressources of the country

PARTNERSHIP ==> OUTCOME FOR THE COUNTRY

==> SOIL RESSOURCES & FARMERS

WHY SOIL RESSOURCES?

(and not food production for example…)

Soils….

A limited ressource,

wisely developped….

through agriculture !

Big success for food production!

IN THE PAST 50 YEARS…….IN THE PAST 50 YEARS…….

+12%

+117%

+200%

World’s cultivated

land

Irrigated area

Agricultural

production

Increments in the past 50 years

High ecological and environmental cost…

• Soils of varying degradation status (low to high) show increasing degradation trends (GLADIS, 2011):

Soil degradation status and trendsSoil degradation status and trends

– Water and wind erosion

– Nutrient and SOM depletion

– Acidification– Salinisation– Compaction – Contamination

SYSTEMS AT RISK SYSTEMS AT RISK (SOLAW)(SOLAW)

B

- A series of land and water systems now face the risk of progressive breakdown of their productive capacity (driven by demographic pressure and unsustainable agricultural practices).

Till now, objective was food self sufficiency

= studies mainly focused on optimizing crop yield (increase fertilizer, irrigation)

Impact on groundwater quality ?

?

From now,

objective sould also be ‘maintaining soil ressources’…

0

1

10

1 10 100 1000Na/

Cl

Chloride (mg/L)

rainfall

Na-plagioclaseweathering

KCl addition(or Na adsorption)

CULTIVATED

FOREST

evapotranspiration

Variations of 2-3 orders of magnitude in Cl, NO3

How to explain such variations ?

Chloride (mg/L)

Comparison pristine vs irrigated agriculture

Importance of soil type on Nitrogen balance

Red soil

(Feralsol)

Black soil

(Vertisol)

Example of Turmerick (irrigated cash crop)

Need to combine monitoring & modeling for understanding N behavior in soil = integrated approach

What are the important parameters ? How to measure them at reasonable cost ?

A limited,

Soils….

…ressource.

non-renewable,

already degraded,

What to do now???

Change our practices:-avoid wasting,-increase recycling…

But most of the soils are already degraded…..

How to do the job?

Using engineers!

Soil and ecosystem engineers…

THE KEY SOIL ENGINEERSTHE KEY SOIL ENGINEERS……

Some examples of Biogenic structuresBiogenic structures

Bioturbation by soil engineers

Formation of biostructures: Biopores & Biogenic aggregates (galeries) (casts, mounds…)

Water infiltration, retention& quality Flood & erosion control

Fertility & productivityGreenhouse gas emission

Modification of soil structureHydrodynamic, SOM decomposition, nutrient cycling

Ecosystem services

21st century farmers have two options…

Firstoption:

THE KEY SOIL ENGINEERSTHE KEY SOIL ENGINEERS……

Second option:

Soil Bio-physical Structural Management(SBSM)

And this is where

becomes an INOVATIVE project…

We want to link natural sciences with economic and social sciences….

After more than 100 yrs of intensification,50 yrs of incredible success in food

production for farmers,

How to shift to soil ressource and environment management?

They are economical factors,And even cultural factors….

Economical factors….

We are asking farmers to abandon a set of techniques that were efficient and take the risk of loosong everything….

Cultural factors….

We will lack of proteins…. And we know all risks

associated with animal breeding…

Eating insects is logical, and is also appreciated!

But even cartesian westerners who do not take any risk will

not easily consider insect as…

How to convince farmers ????

But two tropical countries are different..

But….is this a relevant question????

What kind of research would be useful for farmers, or at least take into account the farmers’ view point?

This is why SBSM needed to be organised in India, to discover and learn from Indian experience…

Experience in the labs and in the fields.

Scientists know the natural processes, but we need to know also ‘agriculture’ and even ‘culture’…

Conclusion….

But solving practical,and necessary complex problems,

we need to launch interdisciplinary researches, effectively interconnected

with synergetic actions.

We have all skills in our own science.

SBSM brings together people who have never worked together and who have

complementary skills between natural and ‘human’ sciences….

The goal is to propose a draft of research project; it still is a challenge….

Thank you for your attention…