Planting frost-sensitive species in intercropping
Preferably establish frost-sensitive species in intercrop covers to avoid having to intervene mechanically or chemically for their destruction.
Presentation
Characterization of the technique
Example of implementation:
Establishing mustard between a winter soft wheat and a spring barley: sowing late August / early September broadcast, at a rate of 10 kg/ha.
Details on the technique:
Rolling the intercrop promotes its destruction by frost.
Application of the technique to...
Implementation period During the intercrop period
Spatial scale of implementation Plot
All crops: Sometimes difficult to generalize, the establishment of frost-sensitive catch crops requires an early harvest of the previous crop (winter cereal straw, rapeseed, protein crops…) to allow sufficient development before the first frosts.
All soil types: Easily generalizable, the establishment of frost-sensitive catch crops can potentially be applied to all soil types. It is of particular interest on hydromorphic soils where the passage for destruction can be difficult due to limited load-bearing capacity.
All climatic contexts: Sometimes difficult to generalize, the choice of frost-sensitive catch crops is of interest in regions where winter temperatures are low enough to allow cover destruction. Conversely, very early low temperatures in the season may not allow sufficient cover development before destruction.
Regulation
The 4th action program of the Nitrate Directive requires full soil cover in winter, which implies the establishment of catch crops on plots not occupied by winter or perennial crops.
Effects on the sustainability of the cropping system
"Environmental" criteria
Effect on air quality: Variable
Phytosanitary emissions: DECREASE
GHG emissions: VARIABLE
Effect on water quality: Increasing
N.P.: DECREASE
Pesticides: DECREASE
The presence of a cover crop during the intercrop period helps limit the risk of transfer of nitrogen, phosphorus, phytosanitary residues, and soil particles to water during this period. Moreover, the choice of frost-sensitive species avoids the use of herbicides for cover destruction.
The establishment and destruction of the cover lead to higher fuel consumption than maintaining bare soil during the intercrop period. But loosening of the profile by the cover may allow reduced tillage for the next crop establishment. Also, the establishment and destruction of the cover cause GHG emissions linked to fuel consumption but also allow carbon storage (if cover develops). The balance is therefore "variable" at the crop scale.
"Agronomic" criteria
Productivity: Variable, if destruction is too late, the catch crop may cause depressive effects on the following crop (water and nitrogen availability). Some catch crops may also have an allelopathic effect on the following crop. But if destruction is early enough and the cover choice appropriate, the cover has a neutral to positive effect on the following crop.
Soil fertility: Increasing, nitrogen captured by the cover during its development is gradually released after its destruction. Part will be directly available for the following crop. The cover also improves phosphorus and potassium availability for the following crop (element remobilization).
Water stress: Variable, water uptake during cover development may increase water deficit.
Functional biodiversity: Increasing, domestic plant biodiversity is enhanced by the establishment of species different from main crops. Moreover, the catch crop provides favorable cover for many animal species (birds, small game, micro and macrofauna...).
Disease pressure:
Establishing catch crops helps "break" rotations and thus disease cycles (e.g. fusarioses, take-all) in cereal rotations. However, the cover may also increase disease pressure if the established species are hosts of the same pathogens as the main crops (establishing crucifers in rotations with high rapeseed return frequency for example).
Pest pressure:
Establishing catch crops can reduce or regulate the presence of certain pests (e.g. nematodes of beet // mustard and radish anti-nematodes). However, the cover may also increase the presence of some pests (slugs, sawflies, flea beetles, aphids) by providing refuge and food.
Soil structuring:
The development of the cover's root system promotes soil restructuring. Moreover, choosing frost-sensitive species can avoid passes for destruction at a time when soil load-bearing capacity is limited.
"Economic" criteria
Operating costs: Increasing. Depending on the species or species mix chosen, seed costs can vary from €10 to €100/ha. Choosing frost-sensitive species avoids herbicide costs related to destruction.
Establishment and destruction of the cover also lead to higher fuel consumption than maintaining bare soil during the intercrop period. But loosening of the profile by the cover may allow reduced tillage for the next crop establishment. Furthermore, choosing frost-sensitive species avoids fuel consumption related to cover destruction.
Mechanization costs: Variable.
Establishment costs can vary from €0/ha (sowing at harvest under the cut) to €60/ha (no-till). However, choosing frost-sensitive species avoids mechanization costs related to cover destruction.
Margin: Decreasing.
Nitrogen returns for the following crop after cover destruction generally do not cover the costs related to its establishment. The overall short-term margin will therefore be reduced. However, "long-term" effects are difficult to quantify and are generally not included in margin calculations (restructuring, erosion limitation, soil life, ...). The cover can also be valorized (harvest, fodder, ...).
"Social" criteria
Working time: Variable
Depending on the mode of establishment, the workload may be more or less than that related to false seedbed preparation during the intercrop period.
Favored or disadvantaged organisms
Favored bioagressors
| Organism | Technique impact | Type | Details |
|---|---|---|---|
| Rapeseed flea beetle | MEDIUM | pest, predator or parasite | Possible presence on covers with crucifers |
| Slug | LOW | pest, predator or parasite | |
| Small flea beetle | MEDIUM | pest, predator or parasite | Possible presence on covers with crucifers |
| Crucifer aphids | MEDIUM | pest, predator or parasite | Possible presence on covers with crucifers |
Disadvantaged bioagressors
| Organism | Technique impact | Type | Details |
|---|---|---|---|
| Cyst nematode | MEDIUM | pest, predator or parasite | Specific mustard varieties "anti-nematodes" |
| Take-all | LOW | pathogen (bioagressor) | By establishing mustard between 2 cereal straw crops |
For more information
- Catch crops - CRA Centre, IBIS Sheet No. 2, Technical brochure, Link to the brochure.
- Catch crops - Better managing the intercrop for agronomic and environmental benefits - Sébastien Minette (CRA Nouvelle Aquitaine) CA Poitou-Charentes, Technical brochure, 2009. Link to the brochure.
- Catch crops - Sébastien Minette (CA Nouvelle Aquitaine), CA Deux-Sèvres, Technical brochure, 2014, Link to the brochure.
- Catch crops, a lever for soil fertility - Barthelmebs C., Barbot C., Kraemer C., Rohrbacher P. (CA 67), Agrimieux Sheet, Technical brochure, 2009. Link to the brochure
Appendices
S'applique aux cultures suivantes
Favorise les bioagresseurs suivants
Défavorise les bioagresseurs suivants
