Establishment of a Flowering Grass Strip to Promote Biodiversity
Among the habitats favorable to beneficial insects and biodiversity possible, there is the establishment of a herbaceous and flowered cover.
Objective
Also called "beetle banks," grass strips are true reservoirs for ground beetles and pollinators[1].
It is possible to maximize the presence of insects beneficial insects by choosing a composition of the herbaceous and flowered cover adapted to the pedoclimatic and economic context of each farm. The composition must however be diverse and mainly based on dicotyledonous plants from various and diverse families[2]. This mix of flowering plants is interesting because it will allow flowering to be spread out as long as possible[3]. During the breeding period (May-June), the herbaceous cover provides a great diversity of insects that are fundamental for the success of broods[4][5].
Functioning
Grasses protect ground-dwelling insects such as ground beetles thanks to their ground coverage (tufted upright form).
Legumes favor dipterans such as syrphids, hymenoptera (wild and domestic bees).
Apiaceae (e.g., caraway) or Asteraceae (e.g., common dandelion) are favorable to a diverse family of insects such as micro-wasp parasitoids (predators of many pests: flea beetles, aphids…)[6].
Expert's word
"Among beneficial insects, it is mainly the larvae that consume or parasitize pests. Adults need pollen and nectar to lay eggs. Flowers are therefore essential to promote natural pest regulation." David Granger, Project Manager for agriculture, wildlife and game damage at the French Office for Biodiversity.
Annual/Biennial mixture
Durability: 1 to 3 years.
Advantages
- Economic: Low-cost and easily available seed.
- Biodiversity: Quickly established refuge. Shelter and cover quickly functional. Production of nectar and pollen in summer and seed supply in wintering period.
Disadvantages
- Economic: Obligation of more frequent reseeding, every 1 to 3 years.
- Biodiversity: Period of vacancy (between destruction of old cover and sowing of new one). Difficult to obtain extended flowering.
Example species
Phacelia, cabbage, Alexandrian clover, buckwheat, millet, sunflower, sorghum, oats, moha, clover, vetch, minette, rye, triticale…
Point of interest
Do not hesitate to sow late in spring to limit competition with weeds and pests.
Perennial mixture
Durability: 5 to 7 years minimum.
Advantages
- Economic: Only one sowing needed for several years. No particular intervention except in case of scrub encroachment (once every 2 to 5 years).
- Biodiversity: Durable refuge over time. Shelter and cover at every time of the year. Extended nectar and pollen production.
Disadvantages
- Economic: Expensive seed and may be difficult to find.
- Biodiversity: Cover takes a long time to establish (2 to 3 years to be fully effective).
Example species
Agglomerated orchardgrass, alfalfa, tall fescue, yarrow, garlic mustard, tall oats, hogweed, crown vetch, dame's rocket, oxeye daisy, meadow clover, sweet clover, clover…
Point of interest
Autumn sowing favors cover establishment.
These 2 types of mixtures are quite complementary at the territorial scale.
Which mixture to choose?
Some species are to be avoided in seed production basins such as wild carrot, wild chicory and wild parsnip (risk of seed lot contamination). For perennial mixtures, it is recommended to choose seeds with the local plant label guaranteeing plants of regional origin. These plants will therefore be better adapted to the pedoclimatic conditions of the farm. It is also the assurance that the flora is well adapted to populations of so-called indigenous or native beneficial insects.
To help you choose the composition of a herbaceous zone to promote beneficial insects of crops, you can refer to this document: (https://arena-auximore.fr/wp-content/uploads/2014/10/Annexes.pdf Optimizing biological control of pests in arable farming systems - Auximore).
To go further
It may be interesting to:
- Mix types and forms of cover on the same linear: alternate grass strip, flower fallow, miscanthus, etc.
- Associate shrubs or a hedge with herbaceous covers.
- Add feeding stations (bucket for supplementary food supply to birds) to promote survival of field birds.
- Add piles of wood or branches on the habitats. These elements will be very favorable for insect overwintering. Moreover, these small mounds are favored by male birds during territorial displays.
Sources
- ↑ Thomas M.B., Wratten S.D., Sotherton N.W.; 1991. Creation of ‘island’ habitats in farmland to manipulate populations of beneficial arthropods: predator densities and emigration. Journal of Applied Ecology, 28, 906-917
- ↑ Wäckers F.L., van Rijn P.C.J.; 2012. Pick and mix: Selecting flowering plants to meet the requirements of target biological control insects. In: Biodiversity and Insect Pests: Key Issues for Sustainable Management (Eds. G.M. Gurr et al.). John Wiley & Sons, Ltd, Chichester, 139–165.
- ↑ Tschumi et al.; 2016. Flower strips for beneficial insects limit pests in arable crops
- ↑ Aebischer N.J., Green R.E., Evans A.D.; 2000. From science to recovery: four case studies of how research has been translated into conservation action in the UK. Pages 140-150 in: J.A. Vickery, P.V. Grice, A.D. Evans & N.J. Aebischer (eds.) The Ecology and Conservation of Lowland Farmland Birds. British Ornithologists’ Union, Tring.
- ↑ Bro. E; 2016. The Grey Partridge. Biology, ecology, management and conservation. Biotope, Mèze, 304p
- ↑ Casdar Muscari (2015-2018), Ministry of Agriculture and Food.
Annexes
- Redirect Modèle:Pages liées
