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Comparative life cycle assessment of perennial and annual crop production: impact of farming systems and management practices
No full textInternational audienceThe Intermediate Wheatgrass (IWG) Thinopyrum intermedium (Host) Barkworth & D.R. Dewey, marketed under the trade name Kernza ® has been tested in France with a group of farmers since 2017. The Life Cycle Assessment (LCA) is a recognized methodology to assess the potential environmental impacts and resources consumption associated with a production system. An attributional LCA following ISO 14040/44 was conducted, focusing on static comparisons. The main purpose of this paper was to estimate the “cradle-to-farm gate” environmental effects caused by the cultivation of intermediate wheatgrassin comparison with the main crops produced, among which soft wheat and maize grain stand out. This research has been achieved with 6 farmers, 3 under organic and 3 under conventional production. A comparative assessment was carried out per year and under 3 years of crop rotation to determine contributions to the environmental impact. Several impact categories were evaluated, including global warming potential (GWP), ozone depletion (OD), freshwater eutrophication (FE) freshwater ecotoxicity (FEC) and acidification (AC). Intermediate wheatgrass (IWG) shows significantly better environmental performance per hectare than annual crops due to its perennial nature with limited soil preparation and lower input requirements. Conversely, IWG performs worse per ton due to its relatively low grain yield. IWG results shows higher contribution of mechanical practices than cash crops with 70% for GWP and OD and 20% with FE, AC and FEC due to low use of fertilizers and pesticides over the 3yr. Grain yields of organically grown crops are lower than those of conventionally grown crops, regardless of the crop. Conventional management shows higher environmental impacts than organic per hectare on IWG but also on annual crops in each category. Conversely organic management on IWG conduct to higher GWP and FE per volume due to regular mechanic weeding, inducing fuel consumption, and organic manure applied before sowing. The results on IWG show significant difference on environmental performance per hectare and per ton between establishment year inducing soil preparation, sowing and fertilization and succeeding years with limited practices except weed management and/or mulching
Combining wheat and diverse perennial species: What is the impact on Z.tritici development and the wheat microbiome?
No full textInternational audienceIncreasing biodiversity in agroecosystems, is desirable for maintaining ecosystem functions, including disease regulation. Strip-intercropping is one of the most effective crop diversification strategy used to limit disease development. However, it generally consists of the association of two crops, whereas several ecological studies recommend highest levels of diversity. In this context, a new cropping system called “Agroprairie” has been designed resulting from the association of alternating strips of wheat and diverse prairies (>10 plant species). The aim of this study is to explore the effect of this new cropping system on the regulation of Zymoseptoria tritici the causal agent of Septoria tritici blotch (STB), one of the most damaging leaf diseases of wheat.To achieve this, four wheat cultivars with contrasting susceptibilities to STB, grown in “agroprairies” associated with four types of prairies (with different growth strategies and legume proportions) were investigated to explore the influence of intra- and interspecific diversity on the development of STB. In addition, a reduced number of plots with the most STB-susceptible cultivar was inoculated with Z.tritici to test the resistance of the associated wheat to inoculation. In parallel, to explore the role of microbiome in disease development, rhizosphere and roots DNA from associated wheat and prairies samples was extracted and sequenced using 16S rDNA. Four different STB incidence and severity notations were recorded between flowering and ripening stage. The results showed that agroprairies with the highest biomass and proportion of legumes reduce the incidence of STB compared to wheat monoculture. However, the protection afforded to wheat by prairie strips is lost when Z.tritici is inoculated, which means that this protection may mainly come from a barrier effect. In parallel, preliminary results show that agroprairies modify the composition of the bacterial rhizospheric and root microbiome of wheat, and increase the abundance of known PGPRs
Combining wheat with multi-species prairie strips reduces the development of Septoria tritici blotch
No full textCrop diversification, notably through intercropping, is known for regulating disease development in agroecosystems. However, intercropping usually involves two or three species, limiting its potential to enhance ecosystem multifunctionality. This study investigates the impact of "agroprairies", a cropping system design consisting of alternating narrow strips of wheat and multispecies prairies (~12 species), on the development of Zymoseptoria tritici, the causal agent of Septoria tritici blotch (STB), a major foliar disease in wheat.Two complementary field experiments were conducted. The first one monitored the incidence and severity of STB under natural epidemic conditions across combinations of four wheat cultivars and four prairie mixtures with contrasted functional traits. The second experiment used above-canopy inoculation on a subset of treatments to assess disease dynamics under high disease pressure, independent of physical barrier effects. Rhizosphere microbiomes were analyzed before inoculation to evaluate potential enrichment in taxa associated with plant defense and disease suppression. Under natural conditions, STB incidence and severity were reduced by 52% and 41%, respectively, in two agroprairie types. Prairie biomass and specific leaf area (SLA) were identified as key factors associated with this reduction. When the disease was inoculated above the canopy, this reduction effect disappeared, highlighting the dominant role of physical barriers in disease regulation. However, one agroprairie treatment still reduced disease progression by 18%, suggesting the involvement of additional regulatory mechanisms. Microbiome analysis revealed shifts in bacterial beta diversity and an enrichment of potentially beneficial taxa in the wheat rhizosphere, although no direct link with disease regulation was established
Influence of high temperatures on the European earwig Forficula auricularia s.l. and the parasitoid Mastrus ridens, two natural enemies of the codling moth Cydia pomonella
No full textInternational audienceA key concern for agriculture is that rising temperatures may disproportionately affect pests and their natural enemies, potentially leading to disruptions in their synchronization or population dynamics, thereby compromising biological control. This study examined whether the European earwig, Forficula auricularia sensu lato (Dermaptera: Forficulidae), a generalist predator native to France, and Mastrus ridens (Hymenoptera: Ichneumonidae), a recently introduced parasitoid of the codling moth Cydia pomonella (Lepidoptera: Tortricidae), can tolerate high temperatures and effectively control this pest under such conditions. Our measurements indicated that the parasitoid and predator were unable to complete their development at temperatures starting from 32 °C and 28 °C, respectively, whereas previous research has shown that the codling moth can develop at 35 °C. Unexpectedly, simulations indicated that + 4°C of global warming could reduce M. ridens generations during the summer in southeastern France. Furthermore, although the parasitism rate of M. ridens remained stable between 20 °C and 30 °C, its total fecundity declined at 28 °C, as did the predation rate of F. auricularia at 30 °C. Additionally, we observed that M. ridens susceptibility to two fungicides, sulfur and copper, and a bioinsecticide, azadirachtin, increased significantly with temperature. Our results thus highlight a significant risk of increased codling moth abundance during the hottest months, driven by the absence or reduced effectiveness of their natural enemies. This underscores the urgent need to implement measures to protect these beneficial organisms under climate change, such as creating microclimatic refuges and reducing the use of pesticides
Growing intermediate wheatgrass as a perennial grain crop in the United States: exploring the multifunctionality of agriculture within socio-technical constraints
No full textThe past decade has seen increasing consideration, stakeholder involvement and investments for growing intermediate wheatgrass (IWG) as a perennial grain crop in the upper Midwest, USA. IWG has been presented as a multipurpose crop able to combine multiple agricultural goods and ecosystem services. The objective of this paper is to comprehend the present IWG situation in the Midwest from the standpoint of farmers growing IWG, encompassing their objectives, practices, and the obstacles they confront. Additionally, it will address the notion of multifunctionality within the framework of introducing a minor crop into farming systems. In total, 18 semi-structured interviews were conducted with IWG growers in the Upper Midwestern US. Results revealed that beyond direct agronomic benefits mentioned by farmers, growing IWG was motivated by a broader approach to agriculture. Thanks to its specific features, IWG was for farmers a tool to accomplish various non-commercial dimensions of farming (e.g., environmental conservation, education, community building) and to fulfil their roles as producers, environmental stewards and citizens. In addition, the regional socio-technical system appeared to impose strong constraints on IWG cropping through profitability assessment and processing issues. Cropping practices reflected the balance between uniform technical recommendations and adaptations to the farming system and farmer’s expertise. This paper provides insights into farmers’ perspectives and concerns regarding IWG in the US
Analogues de viande à haute teneur en eau produits à partir de protéines de féverole, de pois jaune et de soja fonctionnel fractionnées à sec : Effets du plan de mélanges et des paramètres d'extrusion sur les propriétés de texture
No full textInternational audienceThis study, using an augmented simplex centroid design (ASC-DoE), assessed how varying ingredient proportions and extrusion parameters affected the texture of high-moisture meat analogs (HMMAs), exploring faba bean (FB) and yellow pea (YP) dry-fractionated protein concentrates as sustainable alternatives, alone or mixed with functional wet-fractionated soybean protein concentrate (SB) for muscle-like texture. Results showed that pre-treatments enhanced functionality and flowability of FB and YP. Hardness, chewiness, and cutting strength were significantly influenced by total target moisture content (TMC), while screw speed was insignificant. Higher melting temperatures improved FB texture but softened YP. Springiness was minimally influenced by TMC and screw speed but significantly by material composition. Higher protein content and melting temperature promoted longitudinal fiber alignment, essential for meat-like textures. Substituting SB with FB and YP replicated HMMA textures, but color matching remained challenging. These findings establish the synergy between protein combinations and the optimization of extrusion process to meet the need for functional, sustainable plant proteins
14 Adapting Integrated Pest Management to Climate Change
No full textInternational audienceIntegrated pest management (IPM) is a holistic approach to pest control that combines various climate-dependent tactics. This chapter first reviews how climate, mainly temperature, influences four of these tactics: mating disruption, biological control using entomopathogens and entomophagous arthropods, and insecticides. Reports of recent failures in these techniques worldwide highlight the urgent need for adaptations to climate change, which are explored in the second section. The third section discusses recent and ongoing research efforts to ensure that IPM remains a viable production strategy in the context of climate change, using the codling moth Cydia pomonella (Lepidoptera:Tortricidae) as a case study
Alternatives aux néonicotinoïdes en culture de betterave : les avancées de la recherche
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Empowering systemic change at a territory scale: a collective learning experiment with stakeholders along the agrifood chain in the Pilat, France
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Présentation du projet et des dispositifs expérimentaux - Synthèse des travaux conduits dans le cadre du projet CASTOR : des Couverts Végétaux Au Service de la Transition agrOécologique et de la Réduction d’intrants
No full textCe document est le premier d’une suite de trois documents sur la synthèse d’un projet de recherche intitulé CASTOR : des Couverts végétaux Au Service de la Transition agrOécologique et de la Réduction d’intrants. Ce projet s’est intéressé au semis de couvert de légumineuses en relais d’une culture. Ce premier livret retrace la démarche de construction des dispositifs expérimentaux dans les parcelles des agriculteurs. Afin de mieux comprendre les pratiques déjà utilisées sur le terrain, une enquête a été mené auprès d’agriculteurs. Une diversité d’itinéraires techniques a pu être documentée avec des choix autour de trois phases clefs : l’implantation, la gestion pendant l’interculture et la destruction du couvert. Aucune pratique de semis de couvert de légumineuses sous une culture de printemps n’était présente dans notre échantillon. Ces différents résultats ont permis de construire les différentes modalités du réseau d’expérimentation de semis d’un couvert de légumineuses en relais d’une céréale à paille