Crop association in arable crops Carbon cycle and GHG Climate resilience Biodiversity Soil regeneration

Presentation

Characterization of the technique

Description of the technique :

Jean Pierre Sarthou	INRA	sarthou(at)ensat.fr	Castanet-Tolosan (31)
Julien Halska	INRA	julien.halska(at)grignon.inra.fr	Dijon (21)

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The technique consists of not applying pesticides (or a type of pesticide, for example insecticides) nor fertilizers on a few meters wide (1 to 30) at the edge of the crop, depending on the tools used. Insecticide treatments should be avoided first to reduce the pressure on insects (notably auxiliaries and pollinators) and birds (which feed on insects). The absence of fertilizer inputs and herbicide spraying is beneficial for field margin flora. The concerned plots must present a low risk of weed infestation. This practice should only be applied once at the same location during the rotation, be associated with increased monitoring of flora and an adapted weed control program.

Example of implementation : Winter soft wheat: a strip of wheat sown early at the field edge and untreated would limit the development of aphids by favoring auxiliaries such as Hymenoptera parasitoids and Syrphids (at the end of the cycle). However, beware of the risk of BYDV (barley yellow dwarf virus) in barley.

Details on the technique :

Monitor the evolution of flora and entomocenosis (phytophagous, pests or not, and especially auxiliaries).

Implementation period On established crop

Only once at the same location in the rotation.

Spatial scale of implementation Plot

The technique primarily concerns plots most likely to host nests, along grassy strips, hedges, fallows, paths (ideally with crops of spring on one side and winter crops on the other).

Application of the technique to...

All crops : Easily generalizable

The main bibliographic source (Ibis network sheet) only mentions this practice on cereals. However, it seems applicable to other crops. In Switzerland, it is subject to a regulatory measure that applies to rapeseed, sunflower, cereals, and seed legumes.

All soil types : Easily generalizable

All cultivated soils are likely to accommodate the measure, a specific flora may develop over time on each type, whose evolution must be closely monitored.

All climatic contexts : Easily generalizable

Regulations

POSITIVE influence

The widths of Non-Treated Zones along watercourses vary depending on the pesticide concerned and the presence of grassy strips. Widths vary from 5 to 50 meters.

Order of September 12, 2006, relating to the marketing and use of products referred to in Article L.253-1 of the Rural Code, which defines the widths of Non-Treated Zones

Effects on the sustainability of the cropping system

Environmental criteria

Effect on air quality : Increasing

phytosanitary emissions : DECREASE

GHG emissions : DECREASE

particulate emissions : DECREASE

Effect on water quality : Increasing

N.P. : DECREASE

pesticides : DECREASE

Effect on fossil resource consumption : Decreasing

fossil energy consumption : DECREASE

Other : No effect (neutral)

Pollutant transfer to water (N, P, phyto ...): Decrease

Via reduced use and the buffer zone represented by the extensive crop strip (which limits pollutant transfer to surface waters).

Pollutant transfer to air (N, P, phyto ...): Decrease

Via reduced use and the buffer zone represented by the extensive crop strip vis-à-vis neighboring plots or nearby watercourses, by distancing and reducing the treated area.

Fossil energy consumption: Decrease

Modest decrease.

GHG emissions: Decrease

Modest decrease via fuel savings (CO2) and fertilizer savings (N2O).

Biodiversity : Increase

Agronomic criteria

Productivity : Decreasing

Production is slightly reduced on the untreated and unfertilized edge. The seed bank of weeds may be enriched, which can have consequences on the productivity of the cropping system.

Production quality : Decreasing

There is a risk of reduced harvest quality on the untreated and unfertilized zone.

Soil fertility : Increasing

At the level of the extensive crop strip and subject to adapted management (simplified tillage, residue return, which favors soil fauna, increases porosity and thus the useful water reserve).

Water stress : Decreasing

At the level of the extensive crop strip and subject to adapted management (simplified tillage, residue return, which favors soil fauna, increases porosity and thus the useful water reserve).

Functional biodiversity : Increasing

The absence of treatments favors the development of insects, notably pollinators and auxiliaries, soil macrofauna and soil microorganisms. Their development is however strongly linked to the nature and intensity of soil tillage.

Other agronomic criteria : Variable

Risk of weeds development : Increase

The absence of herbicide treatments allows weeds to develop and feed the seed bank.

Economic criteria

Operating costs : Decreasing

Savings on inputs on cereals for an extensive crop strip 12 m wide by 100 m long without pesticides (4 fewer passes) nor fertilizers (three fewer passes): 29 to 25 euros

Mechanization costs : Decreasing

Input savings on cereals for an extensive crop strip 12 m wide by 100 m long without pesticides nor fertilizers (7 fewer passes in total): from 4 to 9 euros.

Margin : Variable

Depending on the difference between yield loss and input savings. The effect also depends on the proportion of the plot concerned by the technique (in our detailed example in other fields, 50 to 70 euros loss for a 55% reduced yield, i.e. 13 to 25 euros less net margin). The smaller this proportion, the less the effect on the crop margin. The effect on the rotation depends on the effect on the weed seed bank.

Other economic criteria : Variable

Fuel consumption: Decrease

Fuel savings on cereals for an extensive crop strip 12 m wide by 100 m long without pesticides nor fertilizers (7 fewer passes in total): 0.5 euros

Social criteria

Observation time : Increasing

Slight increase because bio-aggressors (especially weeds) must be specifically monitored on the untreated and unfertilized zone.

Favored or disadvantaged organisms

Disadvantaged bio-aggressors

Organism	Type	Details
Tomato moth	pest, predator or parasite
mite	pest, predator or parasite
stem weevil	pest, predator or parasite
terminal bud weevil	pest, predator or parasite
beet leafhopper	pest, predator or parasite
wheat leafhopper	pest, predator or parasite
corn leafhopper	pest, predator or parasite
wheat flower gall midge	pest, predator or parasite
pea gall midge	pest, predator or parasite
cockchafer	pest, predator or parasite
slug	pest, predator or parasite
pollen beetle	pest, predator or parasite
cutworm	pest, predator or parasite
autumn aphid	pest, predator or parasite	An early sown and untreated wheat strip at the field edge would limit aphid development by favoring hymenopteran auxiliaries.
black bean aphid	pest, predator or parasite
pea green aphid	pest, predator or parasite
green and pink potato aphid	pest, predator or parasite
green and pink potato aphid	pest, predator or parasite
potato aphids	pest, predator or parasite
crucifer aphids	pest, predator or parasite
aphids vectoring severe yellowing	pest, predator or parasite
aphids vectoring moderate yellowing	pest, predator or parasite
bean moth	pest, predator or parasite
corn borer	pest, predator or parasite
house centipedes	pest, predator or parasite
wireworm	pest, predator or parasite
flax and cereal thrips	pest, predator or parasite
pea thrips	pest, predator or parasite
pea moth	pest, predator or parasite

Favored auxiliaries

Organism	Impact of the technique	Type	Details
Spiders	MEDIUM	Natural enemies of bio-aggressors	Certain species
Predatory and granivorous ground beetles	MEDIUM	Natural enemies of bio-aggressors
Fungi (auxiliary)	MEDIUM	Natural enemies of bio-aggressors	Untreated zones for fungicides.
Green lacewings and antlions	MEDIUM	Natural enemies of bio-aggressors	Adults need flowering plants.
Ladybirds	MEDIUM	Natural enemies of bio-aggressors	Certain species
Insectivorous birds	MEDIUM	Natural enemies of bio-aggressors
Predatory birds	MEDIUM	Natural enemies of bio-aggressors
Parasitoids	MEDIUM	Natural enemies of bio-aggressors
Predatory or granivorous bugs	MEDIUM	Natural enemies of bio-aggressors	including mirids
Rove beetles	MEDIUM	Natural enemies of bio-aggressors
Predatory hoverflies	MEDIUM	Natural enemies of bio-aggressors	If melliferous plants are present in the extensive crop strip.

For further information

Absence of treatment at cereal field edges
-Ibis

Ibis, Technical brochure, 2011

link to the brochure A large part of the information in the sheet comes from this document.

Integrated technical itineraries for winter soft wheat in Picardy
-Mischler P. (AlternatecH) ; Lieven J. (CA Aisne) ; Dumoulin F. (CA Oise) ; Menu P. (CA Somme)

Chamber of Agriculture of Picardy, AlternatecH, INRA, Picardy Region, Technical brochure, 2006

link to the brochure Provides the reference for aphid management by hymenopteran auxiliaries.

Field margin plants
-Conservatoire des espaces naturels du Languedoc-Roussillon, Association Geyser, Chambers of Agriculture of Aude, Gard, Hérault, Lozère, Regional Chamber of Agriculture Languedoc-Roussillon, Regional Federation of Hunters, DIREN, Languedoc-Roussillon Region

Technical brochure, 2011

link to the brochure

Keywords

Bio-aggressor control method : Cultural control

Mode of action : Action on initial stock

Type of strategy regarding pesticide use : Redesign

Appendices

Favorise les auxiliaires

Défavorise les bioagresseurs suivants

Creating Extensive Buffer Strips

Contents