14 research outputs found
Pratiques culturales adaptĂ©es pour rĂ©ussir lâimplantation des cultures intermĂ©diaires
Ce numĂ©ro est constituĂ© dâarticles issus du colloque CIMS : Des Cultures IntermĂ©diaires Multi-Services pour une production agroĂ©cologique performante, organisĂ© le 4 octobre 2017 Ă Auzeville.Succeeding in cover crop establishment means usually an early drilling, in order to face difficultconditions in summertime (soil moisture, straw in the seedbedâŠ). An early establishment after theharvest or even during this operation can be an example. The cover crops are sometimes sown, earlierin the preceding crop with several objectives: help the crop development with companion crops,anticipate the cover crop establishment with perennial species in less dry conditions than insummertime. Manufacturers selling drills, stubble cultivators or mechanical weeding machines purposedifferent solutions to establish cover crops. The best equipment is not present in most of farms becausefarm equipment is chosen for crop establishment and not for cover crop establishment, for economicalreason. The intercropping period is managed in order to find a compromise between different objectives.An early drilling of cover crops has to face different agronomical issues, more or less importantdepending on the fields: lack of water in the soil, excessive temperature, weeds or slugs management,following crop seedbed creation
Pratiques culturales adaptĂ©es pour rĂ©ussir lâimplantation des cultures intermĂ©diaires
La réussite des cultures intermédiaires passe souvent par un semis précoce, de maniÚre à pouvoir
compenser les aléas inhérents à leur implantation en été en conditions parfois sÚches et dans un lit de
semences pailleux. Un semis rapide aprĂšs la moisson ou mĂȘme sous mulch pendant la moisson rĂ©pond
Ă cet objectif. On voit mĂȘme apparaĂźtre des pratiques innovantes oĂč des couverts vĂ©gĂ©taux sont
implantés encore plus précocement, dans la culture précédente, avec plusieurs objectifs (apporter des
services Ă la culture avec des plantes compagnes, anticiper lâimplantation du couvert en conditions
moins sĂšches avec des espĂšces Ă cycle plus long). Au niveau des Ă©quipements, les constructeurs de
matériels de semis, déchaumage ou désherbage mécanique offrent maintenant de nombreuses
solutions pour lâimplantation de cultures intermĂ©diaires. Les Ă©quipements les plus performants ne sont
cependant pas présents dans la plupart des exploitations car les investissements restent avant tout
conditionnés par leur usage pour implanter des cultures de vente et non des cultures intermédiaires. La
gestion de la pĂ©riode de lâinterculture est toujours une question de compromis entre des objectifs
diffĂ©rents. Lâimplantation prĂ©coce des couverts se heurte ainsi Ă diverses contraintes agronomiques,
plus ou moins fortes selon les parcelles (stress hydrique et thermique estival, gestion des adventices,
ravageurs et limaces, prĂ©paration de lâimplantation de la culture suivanteâŠ).Succeeding in cover crop establishment means usually an early drilling, in order to face difficult
conditions in summertime (soil moisture, straw in the seedbedâŠ). An early establishment after the
harvest or even during this operation can be an example. The cover crops are sometimes sown, earlier
in the preceding crop with several objectives: help the crop development with companion crops,
anticipate the cover crop establishment with perennial species in less dry conditions than in
summertime. Manufacturers selling drills, stubble cultivators or mechanical weeding machines purpose
different solutions to establish cover crops. The best equipment is not present in most of farms because
farm equipment is chosen for crop establishment and not for cover crop establishment, for economical
reason. The intercropping period is managed in order to find a compromise between different objectives.
An early drilling of cover crops has to face different agronomical issues, more or less important
depending on the fields: lack of water in the soil, excessive temperature, weeds or slugs management,
following crop seedbed creation
MERCI: a simple method and decision-support tool to estimate availability of nitrogen from a wide range of cover crops to the next cash crop
International audienceBackground and aims Cover crops can efficiently increase nitrogen (N) recycling in agroecosystems. By providing a green-manure effect for the next crop, they allow reduced mineral fertilisation. We developed a decision-support tool, called MERCI, to predict N available from cover crop residues over time, from a single measurement of fresh shoot biomass.Methods We coupled a large experimental database from France with a simulation experiment using the soil-crop model STICS. More than 25 000 measurements of 74 species of cover crops as a sole crop or bispecific mixtures were collected. Linear regression models, at the species, family or entire-database level depending on the data available, were built to predict dry biomass, N amount and C:N ratio. Dynamics of N mineralized and leaching from cover crop residues were predicted at 24 contrasting sites as a function of the biomass, carbon (C):N ratio and termination date. Results Correlations between fresh biomass, dry biomass and N amounts in experimental data were strong (r = 0.80-0.96), and predicted N amounts in fresh shoot biomass were relatively accurate. Percentages of N mineralized and leached simulated bySTICS were explained mainly by the C:N ratio, site and number of months after termination, but to different degrees.Conclusion MERCI is an easy and robust decision support tool for predicting N release in the field, and could thus be adopted by advisors and farmers to improve management of nutrient recycling in temperate arable cropping systems
SystÚmes de culture innovants : une nouvelle génération de réseau expérimental et de réseau de compétences
Face aux Ă©volutions de lâagriculture, aux enjeux complexes et incertains, la conception innovante (Meynard, 2006) doit favoriser le dĂ©veloppement dâune capacitĂ© dâanticipation et dâexploration. Pour y contribuer dans le domaine des systĂšmes de culture en grandes cultures et polyculture-Ă©levage, le programme CASDAR 7103 SystĂšmes de culture innovants sâest concrĂ©tisĂ© par : â un rĂ©seau expĂ©rimental de 27 systĂšmes de culture innovants testĂ©s au champ dans 17 dispositifs, des ressources pour lâexpĂ©rimentation avec des guides, des cadres dâanalyses, des outils de caractĂ©risation et dâĂ©valuation. Aujourdâhui, il a Ă©tĂ© Ă©largi Ă 70 systĂšmes de culture innovants dans le cadre du RMT SdCi ; â un rĂ©seau de compĂ©tences en conception â Ă©valuation, avec quatre ateliers de conception qui ont produit 45 systĂšmes de culture Ă©conomes en phytosanitaires, efficients en Ă©nergie et gaz Ă effet de serre ou favorisant la biodiversitĂ©. Son dĂ©ploiement a Ă©tĂ© rĂ©alisĂ© dans le cadre de formations dâagents de dĂ©veloppement et dâagriculteurs (STEPHY, Certiphyto, DephyĂ©cophyto, âŠ), en Ă©largissant Ă dâautres filiĂšres (viticulture, lĂ©gumes, horticulture, arboriculture) et a pu dĂ©boucher sur des expĂ©rimentations ; â le dĂ©veloppement dâun rĂ©seau de conseillers en accompagnement des agriculteurs dans la transition vers le dĂ©veloppement durable, avec une dĂ©marche dâanalyse rĂ©flexive en groupe des situations de conseil, et plus largement ensuite avec la production et lâĂ©dition du vademecum « Agroseil » (Cerf et al., 2012), de mĂȘme que la formation « Conseiller demain » du GIS Relance agronomique. Le dĂ©veloppement de tels rĂ©seaux de compĂ©tences dĂ©pendra aussi de la capacitĂ© Ă renouveler les dispositifs de recherche â dĂ©veloppement â formation ⊠pour une agriculture innovante et plus durable.To face evolutions of agriculture, complex and uncertain stakes, innovative conception (Meynard, 2006) must favor development of an anticipated and exploratory abilities. To contribute to this in arable and mixed cropping systems, the CASDAR 7103 program was materialized by: â an experimental network of 27 cropping systems tested in field in 17 plans, with experimental resources such as guides, analysis frames and tools of characterization and evaluation. It widened today to 70 innovative cropping systems in the âinnovative cropping systemsâ Joint Network of Technology (JNT); â a conception and evaluation competence network, with four conception workshops which produce 45 cropping systems low in pesticides, efficient in energy and greenhouse gas emission or in favor of biodiversity. Its deployment wad realized thanks to formations of development employees and farmers (STEPHY, Certiphyto, DephyĂ©cophyto, âŠ) in expanding to others fields (vineyard, legumes, horticulture, arboriculture) and in new experimentations; â the development of an advisor network going with farmers in transition to sustainable development, with an approach of reflexive analysis of the advise situations in groups, and then by extension with the production and edition of the vademecum « Agroseil » (Cerf et al., 2012), as well as the formation « Advise tomorrow » of the GIS Relance agronomique. The development of such competence networks will depend also on the abilities to renew the research â development â formation plan ⊠in order to reach an innovative and sustainable agriculture