Diagnosis runoff concept

Julie Maillet-Mezeray, Benoît Réal Arvalis-Institut du Végétal, France

EU Stakeholder Workshop, 26th April 2012, Brussels

Flow theme

Different water pathwaysDatas needed to assess water pathways

Existing audit methodology

Decision support tools to help decision making

Linking water pathway and mitigation measures

Soil surface

Permeability

disruption

Leaching

Surface Run off

Lateral seepage or

drainage

Different water flow pathsPossible ways of transfer for potential pollutantsBMP options adapted to type of water flow path

Audit methodology

Diagnosis tool to prevent the contamination of water by pesticides at field scale

Diagnosis tool to locate and size buffer zones

Based on french approach (ARVALIS – Institut du végétal + CORPEN + IRSTEA)

Optimized among Prowadis partners, focusing on runoff

Audit methodology at plot scale

During both spring and winter time

Based on CORPEN methodology

1

Method

Assess effect of practices

Identification of water circulation and exposed water

-

Data collection

Risk assessment

sol argileux

sauf sol argileux

Propose adapted solutions1. Soil management2. Cropping practices3. Adapting PPP and timing4. Vegetative buffer5. Wetlands

Landscape, farm description, types of soil, geology… with the farmer Hydrology categorisation at the

plot scale

Linking water circulation at plot scale within the

catchment

2

3

4

5

Tillage practices, application periods and PPP Used

Developed by ARVALIS-Institut du végétal : : AQUAPLAINE®

Identify water circulation (step 2)

• Surface runoff (capping, simple surface run off and impermeable surface layer)

Related to permeability of the first layer

• Run off by saturation• Leaching• Lateral seepage• Drainage

Related to permeability into the soil

Soil:Texture, permeability of the surface horizon, coarse fragments and shrinkage cracksSubstrate:Depth, break in permeability and inclination

Landscape:Slope and sinkholesBuffer zones

Adjustments:Drainage and drain performance

Meteorological data

Cultivation dataCrop, date sown and crop rotationTillage pan

Type of water flowin the soil

Direction in which the water is flowing

Effect of practices on water flow

++

Soil saturation

period

+Intensity of water flow

Data to integrate (step 2)

Field observations: concentrated runoff

Sour

ce :

G.L

e H

énaff

- IR

STEA

2012

2012

Sour

ce :

G.L

e H

énaff

- IR

STEA

Field observations: runoff by capping

Field observationson buffer zones

Source : G.Le Hénaff - IRSTEA

Local conditions, local results

0 2 4 6 8 Km

No risk

DrainageSurface runoff, erosion

Catchment of la NonetteCatchment of agripéron

Adapte mitigation measures to pathways

Example 1

Example 2

Solution 1Audited field scale

Double sow in talweg

Establish a buffer in talweg

Solution 2Catchment scale

Stop runoff in the hops

Enlarge the ditch and create a retention pond

along the pathway

Scale of diagnosis case study

2012

JMM - ARVALIS

Solution 1Collecting at the end

Implant a buffer zone edge of the field

Solution 2Preventing at source

Double sow along talweg

Implant a buffer along talweg

Scale of diagnosis case study

Support risk assessment

Catchment + field diagnosis observations

DETERMINE RISK SITUATION

1. Assessment of runoff risk regarding soil caracteristic and landscape

• Restrictions of Infiltration• Saturation excess• Specific for concentrated run off

2. Assessment of runoff risk including practices

3 Assessment of efficiency of buffer zones

Decision trees parametrization

Rest

Description of the characteristic of the soil- clayey and loamy soils (>35% clay, <30% sand)- swelling clays >25%- capping soils

Description of risk level and bunch of proposals

medium (2 to 5%) steep (>5%) medium (2 to 5%) steep (>5%) medium (2 to 5%) steep (>5%)low medium medium high high highI2 I3 I3 I5 I6 I6

Low risk of transfer.

Assess effect of practicesProbably

potentially handle by low

cost BMP :

Medium risk of run off

Assess effect of practices

Use as much practices as

possible: practices on field as well as

lanscape management

if potato : barbutte, dicker + buffer

zones

Medium risk of run off

Assess effect of practices

Use as much practices as possible: practices

on field as well as lanscape

managementif potato : barbutte,

dicker + buffer zones

High risk of run off + erosion

Assess effect of practices

Use as much practices as

possible: practices on field

as well as lanscape

managementif potato :

barbutte, dicker + buffer zones

High risk of run off + erosion

Assess effect of practices

Use as much practices as possible: practices on field as

well as lanscape management

if potato : barbutte, dicker + buffer zones

High risk of run off + erosion

Assess effect of practices

Use as much practices as possible: practices

on field as well as lanscape

managementif potato : barbutte,

dicker + buffer zones

Low

Field adjacent to water body

Medium- clayey and loamy soils (>35% clay, <30% sand)- swelling clays >25%- capping soils

- other textures- no capping of soil

I1

Permeability of the topsoil (infilration rate)High

shallow (0 to 2%)Slope (aggravating runoff)

No risk of transfer by run off.

No need to bother about agricultural

practice.Do whatever you

want.

Low risk of transfer.

Assess effect of practicesProbably

potentially handle by low cost BMP :

I2low

Medium risk of run off

Assess effect of practices

Use as much practices as

possible: practices on field as well as

lanscape management

if potato : barbutte, dicker + buffer

zones

shallow (0 to 2%) shallow (0 to 2%)zero

No drainage

- sandy and sandy loam soil (<35% clay, >65% sand) OR high gravel contents (>50%)- loamy and silty soils (sand + silt >65%) with good aggregate structure and high organic matter content (>3%)- no swelling clays (<25%), no capping

mediumI4

Integrating crop practices

Soil management No-till Disk tillage PloughingVegetation coverCoveredlimited coverNo cover

Concentrated runoff

Yes generated in the audited field

No Yes

Coming from uphill (generated on a field up in

catchment)

Concentrated

Slightly Clearly concentratedConcentrated in

Wheel tracksConcentrated in

cornerConcentrated in

access areaStraight to slope (through talweg)

Straight to slope (trough talweg)

Need to prevent concentrated run

off up in catchment

Make audit of the field where

run off generated

Need to prevent generation of

concentrated run off in wheel tracks

Need to prevent generation of

concentrated run off coming in corner,

specially if in direct contact with waterNeed to collect it

specially if in direct contact with water

Check outlet of concentrated run

off .If going down on

road can contaminate water

further down

Double sowing ? straight to slope

Gully can be observedPrevent at sources

Intercept on its way down

Measure related to Landscape

management to be applied

Buffer may be useful to

intercept run off.

See measure : Manage wheel tracks,Run across the slope

if possible, Practice double

sowing in some area, Enlarge headland

Buffer zones in corner if corner is not

hydromorphic

See measure : Manage field access area

Buffer straight to slope buffer

Different scales for the diagnosis

Catchment

Area Region: Decision making unit for stakeholders

Catchment: Investigation unit to understand transfer and implement suitable action plan

Fields: Units to understand the movement of excess water: In different locations in the catchmentAt different period of time

Farm: Decision making unit

Conclusion

Field audit needed

Methodology available

Help tool to support audit: decision trees in progress

Practical, acceptable, implementable