Composition des prairies temporaires :a lever of resilience and enhancement
.jpg)
In addition to contributing to the reduction of inputs, integrating temporary grasslands into a rotation is a powerful and inexpensive lever for the food autonomy of ruminant livestock.
Unfortunately, two factors tend to limit the optimal valorization of these grasslands :
- The seasonality : In systems where these are mainly grazed, grasslands generally do not meet the herd's nutritional needs during winter or periods of high heat.
- The climate change : Average changes in climatic variables (precipitation, atmospheric CO2 levels, temperature, etc.), increased variability, and interactions between these variables can compromise the productivity of temporary grasslands both in terms of quantity and quality of the grass produced[1].
Reflection on the composition of temporary grasslands, aligned with local specificities, can nevertheless address these two issues. This article presents the different parameters to consider when composing a resilient grassland, as well as a list of grassland species and varieties adapted to grazing in winter and/or known for their climate resilience.
Introductory Concepts
Multi-species grasslands
This term refers to temporary grasslands composed of a mixture of at least 3 species, from two different plant families [2] (most often grasses and fabaceae). From a certain level of persistence (3 years) and diversity (6 species (and varieties) from at least 3 botanical families for grazed grasslands (2 families for mown grasslands), it is even called "Diverse Flora Grassland" (DFG) [3]. Such species and varietal diversity primarily makes these ecosystems more resilient to extreme climatic events [4], but it also generally offers better growth distribution, better persistence, and good nutritional complementarity.
Species selection criteria
When composing a temporary grassland, choosing the species to plant can be a delicate decision. It must be motivated by various criteria.
- The first is the desired production period, it is indeed important to define beforehand whether one wants to valorize grass growth :
- At the beginning of spring, or at the end of spring / beginning of summer.
- Then via a regrowth in summer or a regrowth in autumn.
- The second criterion is the mode of grassland use, so species must be selected according to whether they are better suited for grazing or mowing, and in the latter case for silage, baling or green feeding. Similarly, it is necessary to consider the persistence of a species and its sensitivity related to the local pedoclimatic context and the grassland lifespan.
- The third criterion to consider is the speed of establishment of the species chosen; the faster a plant establishes, the less sensitive it will be to weed competition.
- Finally, one of the last main criteria is the nutritional value of the species concerned. The yield of a grassland is generally expressed in DM (Dry Matter Tons) per unit area, its energy value in UF (UFL for Milk Forage Unit, and UFV for Meat) and its protein content in PDIE (Digestible Proteins in the Intestines allowed by Energy) or PDIN (allowed by Nitrogen) or sometimes via the BPR (Rumen Protein Balance).
Variety selection criteria
Management flexibility
For a temporary grassland, this term refers to the period during which the farmer can graze it in the year following its establishment (from a sufficiently advanced growth stage until heading). The longer this period, the greater the management flexibility of a variety.
Ploidy
The ploidy of a variety refers to its number of chromosomes : Most species are naturally diploid (their chromosomes are paired and associated as homologous pairs : noted 2n). However, breeding has produced tetraploid varieties (two similar pairs for each chromosome : noted 4n), these varieties have the following traits :
- They are richer in water.
- Their stems are thicker and less numerous.
- Their leaves are wider and longer.
- Their seeds are larger.
By extension, tetraploid varieties are often more resistant to climatic hazards than diploids, and also more adapted to grazing due to lower dry matter content [5].
Regrowth and alternation
- Regrowth is the ability of a plant to produce new ears after an exploitation (mowing, grazing, etc.) that removed those from the previous growth. In grasses, ear growth promotes dry matter production, facilitates mowing but decreases nutritional value. Conversely, for grazing, species and varieties with low regrowth are preferred to maximize leaf production, which is more palatable and nutritionally valuable.
- Alternativity of a variety refers to its tendency to produce ears in the year of sowing. Similarly, varieties with low alternativity are preferred for pastoral systems. [5]
Dormancy
The state of the plant during which vegetative development (growth) is halted during winter; this vegetative rest allows plants to better withstand winter stresses (frost, low temperatures, snow cover, etc.). The dormancy period of a variety is generally quantified by a score ranging from 1 (very dormant) to 12 (non-dormant), notably for alfalfa [6].
Disease resistance
Finally, selecting varieties resistant to diseases can be a real lever for grassland productivity and resilience.
Grassland species
Below is a list of species that can be integrated into long-term temporary grasslands (+ over 3 years) with, when available, information on the selection criteria presented above.
Grasses (Poaceae)
Perennial Ryegrass (Lolium perenne) [7]
_-_cultivated.jpg)
Persistence : 3 to 6 years.
Use : Mowing and grazing.
Seeding rate : 20 to 30 kg/ha pure stand and 10 to 15 kg/ha in mixture.
Additional info : Growth stops with heat (>25°C), tolerant to excess water. Often associated with white clover.
Notable varieties : The varieties "Careva" (2n) and "Byzan" (4n) are the most productive in summer/autumn. [8]
Hybrid Ryegrass (Lolium ×hybridum Hausskn.) [9]
Persistence : 3 to 4 years.
Use : Mowing and grazing.
Seeding rate : 20 to 30 kg/ha pure stand and 10 to 15 kg/ha in mixture.
Additional info : Sensitive to drought, good early spring growth. Often associated with clover violet.
Notable varieties : The variety "Palmata" is the most persistent, and "Baradil" the least disease sensitive. [8]
Orchardgrass (Dactylis glomerata) [10]
Persistence : 4 to 8 years.
Use : Mowing and grazing.
Seeding rate : 15 to 20 kg/ha pure stand.
Additional info : Very drought resistant, good energy and protein content. Sensitive to excess water and cold, heavy heading the first year. Often associated with alfalfa. Late establishment but good regrowth in summer and autumn.
Notable variety : The variety "Archibaldi" has the earliest vegetation start (03/24). [8]
Tall fescue (Festuca arundinacea) [11]
Persistence : 6 to 10 years.
Use : Mowing and grazing.
Seeding rate : 15 to 25 kg/ha pure stand and 3 to 15 kg/ha in mixture.
Additional info : Adapted to all soil types, cold and heat, slow establishment, good regrowth in summer and autumn, resistant to trampling and excess water. Loss of palatability at advanced stage: a varietal choice factor.
Notable varieties : The variety "Rorante" has the earliest vegetation start (03/05), and "RGT nougat" is the most palatable. [8]
Meadow fescue (Festuca pratensis) [12]
Persistence : 4 to 5 years.
Use : Mowing and grazing.
Seeding rate : 15 to 25 kg/ha pure stand and 3 to 15 kg/ha in mixture.
Additional info : Species adapted to winter excess water, slow establishment and low regrowth. Sensitive to drought but not to heat (growth stops at 30 - 33°C).
Notable variety : "Prayola" is the earliest and most productive variety. [8]
Festulolium (×Festulolium loliaceum) [13]
Persistence : 3 to 5 years.
Use : Mowing and grazing.
Seeding rate : 15 to 25 kg/ha pure stand and 3 to 15 kg/ha in mixture.
Additional info : Hybrid between ryegrass and fescue, can take characteristics of either depending on varieties.
Notable variety : The variety "Hipast" is currently the most productive and persistent on the market. [8]
Timothy (Phleum pratense) [14]
Persistence : 3 to 5 years.
Use : Mowing and grazing.
Seeding rate : 3 to 7 kg/ha.
Additional info : More adapted to cold or mountainous areas, grows later in spring and in mild winter : grazable in winter. Good resistance to acidic and/or flooded soils. Possible Priming and slow establishment.
Notable variety : The variety "Cantal" is the earliest and most disease resistant. [8]
Crested brome (Bromus catharticus) [15]
.jpg)
Persistence : 3 to 5 years.
Use : Mowing and grazing.
Seeding rate : 50 to 60 kg/ha pure stand and 20 kg in association with legumes.
Additional info : Sensitive to cold, excess water and trampling in wet soils. Earlier vegetation start than Siberian brome.
Notable variety : /
Siberian brome / Alaska brome (Bromus stichensis) [15]
Persistence : 3 to 5 years.
Use : Mowing and grazing.
Seeding rate : 40 to 45 kg/ha pure stand and 20 kg in association with legumes.
Additional info : More cold resistant, sensitive to excess water and trampling in wet soils. Less alternating and less regrowing than crested brome, grows earlier in spring.
Notable variety : /
Kentucky bluegrass (Poa pratensis) [16]
.jpg)
Persistence : 4 to 8 years.
Use : Mowing and grazing.
Seeding rate : 15 to 25 kg/ha pure stand and 5 to 15 kg/ha in mixture.
Additional info : Adapted to dry climates and overgrazing. Tolerates extreme weather and fills in gaps after such hazards. Slow initial development and low nutritional value.
Notable variety : /
Legumes (Fabaceae)
White clover (Trifolium repens) [17]
Persistence : 4 to 5 years.
Use : Mainly grazing.
Seeding rate : 2 to 4 kg/ha for 15 to 20 kg of grasses in mixture.
Additional info : Not very drought tolerant, but rather heat resistant.
Notable variety : The variety "Triffid" is the most vigorous after winter. [8]
Hybrid clover (Trifolium hybridum) [17]
Persistence : 2 to 4 years.
Use : Grazing and mowing.
Seeding rate : 10 to 15 kg/ha pure stand and 2 to 4 kg/ha for 15 to 20 kg of grasses in mixture.
Additional info : Cold resistant, and tolerant to compacted, wet, and asphyxiated soils. Not very drought tolerant.
Notable variety : /
Red clover (Trifolium pratense) [17]
Persistence : 2 to 3 years.
Use : Grazing and mowing.
Seeding rate : 12 to 15 kg/ha for 8 to 12 kg of grasses in mixture.
Additional info : Adapted to acidic soils, sensitive to drought, unsuitable for silage.
Notable variety : The variety "Corvus" is the most persistent. [8]
Bird's-foot trefoil (Lotus corniculatus) [17]
Perenniality : 2 to 4 years.
Use : Grazing and mowing.
Seeding rate : 12 to 15 kg/ha with 8 kg of grasses in mixture.
Additional information : Suitable for dry soils, non-bloating plant, slow establishment and low aggressiveness, sensitive to trampling.
Notable varieties : /
Black medick / Hop trefoil (Medicago lupulina) [17]
Perenniality : 1 to 4 years.
Use : Grazing and mowing.
Seeding rate : 15 to 20 kg/ha pure, 2 to 4 kg/ha with 15 to 20 kg of grasses in mixture.
Additional information : Non-bloating species, allows valorization of low potential soils, slow establishment, sensitive to excess water.
Notable variety : /
Sainfoin / esparcet (Onobrychis viciifolia)
_-_geograph.org.uk_-_832203.jpg)
Perenniality : 2 to 3 years.
Use : Grazing and mowing.
Seeding rate : 40 to 50 kg/ha pure.
Additional information : Drought and cold resistant but sensitive to excess water. Poorly suited to mixtures due to low aggressiveness. Unsuitable for clay and acidic soils. Highly melliferous species.
Notable variety : The "Perdrix" variety is the most perennial and disease resistant.[18]
Alfalfa (Medicago sativa) [17]
Perenniality : 3 to 5 years.
Use : Mowing only if pure stand (too bloating to be grazed).
Seeding rate : 15 to 20 kg/ha pure, 10 to 15 kg/ha with 12 to 14 kg of grass in mixture.
Additional information : Sensitive to excess water and acidic soils, highly drought resistant, high yields and good valorization in wrapped silage. Unsuitable for ensiling (low energy content).
Notable variety : The "Luzelle" variety is one of the most winter cold resistant with a dormancy rating of 2.1.
Other families
Ribwort plantain (Plantago lanceolata) [19]
Perenniality : 3 years.
Use : Mainly grazing.
Seeding rate : 1 to 3 kg/ha with 15 to 20 kg of grasses in mixture.
Additional information : Very drought resistant, also resistant to hydromorphic soils. Proven antiparasitic effect on small ruminants, high seed cost (10 to 16€ / kg).
Notable varieties : The main variety used is "Cérès tonic".
Forage chicory (Cichorium intybus) [20] [21]
Perenniality : 3 to 4 years.
Use : Mainly grazing, due to low dry matter content.
Seeding rate : 1 to 5 kg/ha in mixture with grasses and legumes.
Additional information : Very drought resistant, adapted to summer grazing, contains vermifuge substances. High regrowth rate : a varietal selection factor.
Notable varieties : /
Further reading
To select one or more grassland varieties based on multiple criteria, consult the Herbe-Book database.
Visit the website of EILYPS, consulting and expertise company in livestock :
Sources
- ↑ J.-F. Soussana, “Grasslands and climate change”, Fourrages, 215, 171-180, 2013. https://afpf-asso.fr/index.php?secured_download=2052&token=c16b0ba6e27c1efb0d74a94026afe433
- ↑ R. Brochier, ARVALIS Plant Institute. Multi-species grasslands, a solution to achieve forage autonomy. 2017. https://www.arvalis-infos.fr/les-prairies-multi-especes-une-solution-pour-atteindre-l-autonomie-fourragere-@/view-12178-arvarticle.html#:~:text=Une%20prairie%20multi%2Desp%C3%A8ces%20se,des%20gramin%C3%A9es%20et%20des%20l%C3%A9gumineuses.
- ↑ V. Goutiers et Al. INRAE, Capflor® : a tool to design diverse flora grasslands, 2016. https://www.researchgate.net/profile/Laurent-Hazard-2/publication/313078685_CapflorR_un_outil_pour_concevoir_des_melanges_de_prairies_a_flore_variee/links/588f8e53aca272bc14bc5a1e/CapflorR-un-outil-pour-concevoir-des-melanges-de-prairies-a-flore-variee.pdf
- ↑ F. Isbell, D. Craven, J. Connolly, et al. Biodiversity increases the resistance of ecosystem productivity to climate extremes. Nature 526, 574–577 (2015). https://doi.org/10.1038/nature15374
- ↑ 5.0 5.1 SEMAE Pedagogy, Seed sector educational resources. Grassland Species and Variety Choice : 2/7 Variety Selection. Accessed February 2022. https://www.semae-pedagogie.org/sujet/plantes-prairiales-choix-varietes-fourrageres/
- ↑ Herbe'Actifs, SEMAE grassland and forage magazine: seed and plant interprofessional, Variety choice for alfalfa. 2012https://herbe-actifs.org/especes/choisir-variete-luzerne
- ↑ GNIS, Alliance élevage, Perennial ryegrass, 2017. https://www.alliance-elevage.com/informations/article/le-ray-grass-anglais
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 SEMAE, GEVES, Arvalis, AFPF, Herbe-book : the online database of forage varieties. Accessed February 2022. https://www.herbe-book.org/
- ↑ SEMAE (GNIS), Choice of forage species and varieties : hybrid ryegrass, accessed February 2022. http://www.plantesfourrageres.org/pages/rgh01.htm
- ↑ SEMAE (GNIS), Choice of forage species and varieties : orchardgrass, accessed February 2022. http://www.prairies-gnis.org/pages/dactyl1.htm
- ↑ Herbe'Actifs, SEMAE grassland and forage magazine: seed and plant interprofessional, Tall fescue, 2020. https://herbe-actifs.org/especes/fetuque-elevee
- ↑ Herbe'Actifs, SEMAE grassland and forage magazine: seed and plant interprofessional, Meadow fescue, 2020. https://herbe-actifs.org/especes/fetuque-des-pres
- ↑ M. Deraedt et al., AFPF, Agronomic recommendations for seed mixtures for grasslands in France, 2014.http://www.fourragesmieux.be/Documents_telechargeables/Plaquette_AFPF_Melanges.pdf
- ↑ SEMAE (GNIS), Choice of forage species and varieties : timothy, accessed February 2022. http://www.plantesfourrageres.org/pages/fleole.htm
- ↑ 15.0 15.1 A. Besnard et al. ARVALIS, Main forage species and management elements, 2012. http://www.editions-arvalis.fr/file/galleryelement/pj/6b/9b/af/9d/___74242245860781531882.pdf
- ↑ E. Moismann, J. Lehmann, AFPF, Use of Kentucky bluegrass (Poa pratensis L.) for creating long-term grasslands, 1996. https://afpf-asso.fr/article/utilisation-du-paturin-des-pres-poa-pratensis-l-pour-la-creation-de-prairies-de-longue-duree
- ↑ 17.0 17.1 17.2 17.3 17.4 17.5 Herbe'Actifs, SEMAE grassland and forage magazine: seed and plant interprofessional, Each use its species, 2012. https://herbe-actifs.org/agronomie/chaque-utilisation-son-espece
- ↑ D. Suter, R. Frick, H-U. Hrischi, Agroscope, Liste 2019-2020 des variétés recommandées de plantes fourragères. 2019 https://www.agrarforschungschweiz.ch/fr/2019/01/liste-2019-2020-des-varietes-recommandees-de-plantes-fourrageres/
- ↑ CEDAPA (Centre for studies for more autonomous agricultural development). Establishing ribwort plantain in grasslands. 2017. http://www.cedapa.com/wp-content/uploads/2018/10/Implanter-du-plantain_finie.pdf
- ↑ CEDAPA, Choice of species and grassland varieties, Accessed February 2022. http://www.cedapa.com/wp-content/uploads/2013/10/vari%C3%A9t%C3%A9-et-esp%C3%A8ces.pdf
- ↑ IDELE, Introducing chicory into multi-species grazing grasslands, 2018. http://idele.fr/fileadmin/medias/Documents/Optialibio/Optialibio_Fiche_Chicoree_20170125.pdf
