1. Diagnosis runoff concept Julie Maillet-Mezeray, Benoît Réal Arvalis-Institut du Végétal, France EU Stakeholder Workshop, 26th April 2012, Brussels

2. Flow theme Different water pathways  Datas needed to assess water pathways Existing audit methodology Decision support tools to help decision making

3. Linking water pathway and mitigation measures Soil surface Permeability disruption Leaching Surface Run off Lateral seepage or drainage Different water flow paths Possible ways of transfer for potential pollutants BMP options adapted to type of water flow path

4. Focus on run off Ingredientes are more often quantified in run off water than in drainage water. Concentration of ingredientes are higher in run off water than in drainage water. Run off

5. 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

6. 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 solutions 1.Soil management 2.Cropping practices 3.Adapting PPP and timing 4.Vegetative buffer 5.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®

7. 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

8. Soil: Texture, permeability of the surface horizon, coarse fragments and shrinkage cracks Substrate: Depth, break in permeability and inclination Landscape: Slope and sinkholes Buffer zones Adjustments: Drainage and drain performance Meteorological data Cultivation data Crop, date sown and crop rotation Tillage pan Type of water flow in 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)

9. Field observations: concentrated runoff Source : G.Le Hénaff - IRSTEA 2012 Source : G.Le Hénaff - IRSTEA

10. Field observations: runoff by capping

11. Field observations on buffer zones Source : G.Le Hénaff - IRSTEA

12. Local conditions, local results No risk Drainage Surface runoff, erosion Catchment of la Nonette Catchment of agripéron Adapte mitigation measures to pathways

13. Solution 1 Audited field scale Double sow in talweg Establish a buffer in talweg Solution 2 Catchment 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

14. Solution 1 Collecting at the end Implant a buffer zone edge of the field Solution 2 Preventing at source Double sow along talweg Implant a buffer along talweg Scale of diagnosis case study

15. 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

16. 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

17. Integrating crop practices Soil managementNo-tillDisk tillagePloughing Vegetation cover Covered limited cover No cover

18. Concentrated runoff Yes generated in the audited field No Yes Coming from uphill (generated on a field up in catchment) Concentrated SlightlyClearly concentrated Concentrated in Wheel tracks Concentrated in corner Concentrated in access area Straight 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 water Need 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 observed Prevent 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

19. 19 Diagnosis tool to locate and size buffer zones Regulatory context coming in EU: buffer along rivers with a narrow strip May not be sufficient when need to protect important ressources (drinking water, …) in a catchment Need for a two steps local diagnosis to verify presence and efficacy of riparian buffers if necessary, to propose the implementation of a complementary buffering device: widening of riparian buffers implementation of in-field buffers implementation of buffer along "non-compulsory" brooks and upstream ditches 1 2 3

20. Different scales for the diagnosis Catchment Area

21. Conclusion Field audit needed Methodology available Help tool to support audit: decision trees in progress Practical, acceptable, implementable