1. Presentation

Characterization of the technique

Description of the technique:

François Dumoulin	CA 60	francois.dumoulin(at)agri60.fr	Fresnoy le Luat (60)
Lionel Jouy	Arvalis	l.jouy(at)arvalisinstitutduvegetal.fr	Boigneville( 91)
Aimé Blatz	INRA	aime.blatz(at)colmar.inra.fr	Colmar (68)
Sébastien Minette	CRA Poitou-Charentes	sebastien.minette(at)poitou-charentes.chambagri.fr	Lusignan (86)
Nicolas Munier-Jolain	INRA	nicolas.munier-jolain(at)dijon.inra.fr	Dijon (21)
Pascal Farcy	INRA	pascal.farcy(at)epoisses.inra.fr	Epoisses (21)
Julien Halska	INRA	julien.halska(at)grignon.inra.fr	Epoisses (21)

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Alternate winter crops and spring crops in the rotation. The sequence will ideally include crops sown in each of the following periods: 1. late summer/early autumn (e.g. rapeseed) ; 2. late autumn/winter (soft wheat, durum wheat, winter barley, winter peas) ; 3. late winter/early spring (barley, spring peas) ; 4. spring (corn, beet, sunflower). It is preferable to have a slightly higher proportion of winter crops than spring crops. Strong alternations such as 2 winter crops followed by 2 spring crops are possible. Choose varied crops depending on the pedo-climatic context of the plot. Note, this page does not concern delayed sowing nor early sowing, which have dedicated pages.

Example of implementation:

Switching from a Winter rapeseed / Soft winter wheat / Winter barley rotation to Winter rapeseed / Soft winter wheat / Spring barley, and/or introducing spring peas: Winter rapeseed / Soft winter wheat / Spring barley / Spring peas

Details on the technique:

Works mainly with weeds with a narrow emergence window, influenced by the possibility to work the soil at different times of the year. Little effect on thistles.

Influence of the possibility to work the soil at different times of the year.

Implementation period On established crop

Possibility to perform strong alternations (e.g. 2 spring crops // 2 winter crops).

Spatial scale of implementation Plot

Application of the technique to...

All crops: Sometimes difficult to generalize

It is sometimes not possible to introduce diversified crops. Adapt according to the potential of certain crops (crops sown in late spring on soils with low available water capacity, or without irrigation) or relative to the days available for sowing (hydromorphic soils for late winter-early spring crops).

All soil types: Sometimes difficult to generalize

Diversification of crops is sometimes difficult and must be adapted to soil characteristics (low available water capacity, hydromorphy, workability, ... ) which do not always allow a wide choice of crops. The presence of irrigation can facilitate the introduction of different crops (spring crops). This technique is well suited to soils with medium to high available water capacity, non-hydromorphic and with fairly rapid drying in spring.

All climatic contexts: Sometimes difficult to generalize

The pedo-climatic context can limit the possibilities of diversifying sowing dates, especially in regions with marked spring water deficit (e.g. Southwest France).

Regulation

The nitrate directive requires sowing a cover crop before spring crops in vulnerable zones. This can hinder the adoption of these crops. Conversely, rotational agri-environmental measures (MAE) encourage diversified rotations through subsidies.

Nitrate directive

Rotational MAE

2. Services provided by the technique

3. Effects on the sustainability of the cropping system

"Environmental" criteria

Effect on air quality: Increasing

phytosanitary emissions: DECREASE

GHG emissions: UNKNOWN

Effect on water quality: Increasing

pesticides: DECREASE

Effect on fossil resource consumption: Variable

fossil energy consumption: VARIABLE

Other: No effect (neutral)

Air : Limiting the use of herbicides.

Water : Limiting the use of herbicides.

Fossil energy : Crop alternation allows additional mechanical weedings, possibly increasing fuel consumption. It also allows the introduction of legumes, thus enabling significant savings on nitrogen fertilizers and the fossil energy required for their production.

Landscape quality, wild animal populations : Increase

Varied landscape (color, crop type), increase and diversification of habitat areas for wildlife.

"Agronomic" criteria

Productivity: Variable

Increase in yields of each crop by maintaining or improving the physico-chemical fertility of the soil and better control of bio-aggressor development. Depending on previous effects (reduction for a given crop of weed pressure), thus improvement or preservation of the potential yield of each crop. However, introduction of diversification crops, less productive in terms of biomass produced/ha.

Soil fertility: Increasing

Crops explore the soil differently, do not extract the same mineral elements, and crop diversity promotes diversity of soil microbial populations.

Water stress: No effect (neutral)

Functional biodiversity: Increasing

Each crop favors certain wild species to varying degrees. By diversifying crops to vary sowing dates, biodiversity is promoted. However, the existence of long intercrops in rotations can result in more intense and regular soil work, which may harm soil macrofauna.

Other agronomic criteria: Decreasing

Populations of bioagressors (diseases, insects) : Decrease

A network of diversified crops in a territory can limit the spread of certain bioagressors. Similarly, species diversification on a plot limits the development and multiplication of crop diseases or pests (e.g. powdery mildew, foot lodging, nematodes, broomrape, sclerotinia). The presence of summer crops allows soil work to effectively combat slugs.

"Economic" criteria

Operational costs: Decreasing

Less herbicides, pesticides (rotation effect) and nitrogen (when introducing legumes).

Mechanization costs: Variable

Introducing new crops may require acquiring specific equipment (seeder, stubble cultivator). But work peaks can be leveled, limiting equipment size and sometimes required traction power.

Margin: Variable

For each crop, variable evolution of costs and yield increase, thus variable margin evolution. In the rotation, introduction of sometimes less profitable crops. Need to consider gross and direct margins over the entire sequence.

Other economic criteria: Variable

Fuel consumption: variable

Varies depending on chosen crops.

Market opportunities : Decrease

Diversity in sowing periods generally leads to species diversity. It can be difficult to find markets for some of these species.

"Social" criteria

Working time: Variable

Depending on chosen crops and the need to increase mechanical weeding.

Peak period: Decreasing

Reduction of "work overload" periods (e.g. autumn) by spreading tasks but different distribution over the year (fewer "quiet" periods), but fragmentation of some operations (spraying for example) which may increase tool preparation and travel time.

Observation time: Increasing

Due to the diversity of crops to monitor.

Need for farmer training : Increasing

It is necessary to learn how to manage new crops. Moreover, for some diversification crops there is not always local reference (neighboring farmers, advisors competent on specific crops).

4. Favored or disadvantaged organisms

Favored bioagressors

Organism	Impact of the technique	Type	Details

Disadvantaged bioagressors

Organism	Impact of the technique	Type
White amaranth	MEDIUM	weeds
Prostrate amaranth	MEDIUM	weeds
Hybrid amaranth	MEDIUM	weeds
Reflecting amaranth	MEDIUM	weeds
Theophraste's abutilon	MEDIUM	weeds
Wind grass	MEDIUM	weeds
Thalius' rockcress	MEDIUM	weeds
Common mugwort	MEDIUM	weeds
Intermediate barbarée	MEDIUM	weeds
Tripartite bident	MEDIUM	weeds
Irregular calepine	MEDIUM	weeds
Bristly cardamine	MEDIUM	weeds
Corn marigold	MEDIUM	weeds
Nîmes hawkweed	MEDIUM	weeds
Jimsonweed	MEDIUM	weeds
Red digitgrass	MEDIUM	weeds
Common fennel	MEDIUM	weeds
Field gromwell	MEDIUM	weeds
Cock's-foot panic	MEDIUM	weeds
Field passerage	MEDIUM	weeds
Drave passerage	MEDIUM	weeds
Whorled bristlegrass	MEDIUM	weeds

Favored Auxiliaries

Organism	Impact of the technique	Type	Details

Disadvantaged auxiliaries

Organism	Impact of the technique	Type	Details

Favored climatic and physiological accidents

Organism	Impact of the technique	Details

Disadvantaged climatic and physiological accidents

Organism	Impact of the technique	Details

5. For further information

More effective alternatives to herbicides
-Gloria C. (Réussir Grandes Cultures)

Réussir grandes cultures, 19/09/2008, Press article, 2008

article

Cleaner plots with less herbicides
-Mischler P., Lheureux S., Dumoulin F., Menu P., Sené O.

Agrotransfert Resources and Territory / Chambers of Agriculture Aisne, Oise and Somme, Technical brochure, 2007

link to brochure

Integrated production and weeds
-Pernel J.

Agrotransfert Resources and Territory / Chambers of Agriculture of Picardy / ENITA Clermont-Ferrand, University work, 2008

Engineering thesis

Crop protection strategies saving phytosanitary products
-Gran-Aymerich L.

Ministry of Agriculture and Fisheries, ENSA Montpellier, Technical brochure, 2006

Design and multicriteria evaluation of cropping system prototypes within Integrated Weed Management in field crops.
-Munier-Jolain N. (INRA) ; Deytieux V. (INRA) ; Guillemin J.P. (Agrosup Dijon) ; Granger S. (Agrosup Dijon) ; Gaba S. (INRA)

Innovations Agronomiques 3, 75-88, Peer-reviewed article, 2008

link to article

6. Keywords

Bioagressor control method: Cultural control

Mode of action: Avoidance

Type of strategy regarding pesticide use: Redesign

Annexes

Est complémentaire des leviers

Collecting small straw during harvest

Défavorise les bioagresseurs suivants

Growing species with varied planting periods

Contents