Assessment of Benefits of Conservation Agriculture on Soil Functions in Arable Production Systems in Europe

Conventional farming (CONV) is the norm in European farming, causing adverse effects on some of the five major soil functions, viz. primary productivity, carbon sequestration and regulation, nutrient cycling and provision, water regulation and purification, and habitat for functional and intrinsic biodiversity. Conservation agriculture (CA) is an alternative to enhance soil functions. However, there is no analysis of CA benefits on the five soil functions as most studies addressed individual soil functions. The objective was to compare effects of CA and CONV practices on the five soil functions in four major environmental zones (Atlantic North, Pannonian, Continental and Mediterranean North) in Europe by applying expert scoring based on synthesis of existing literature. In each environmental zone, a team of experts scored the five soil functions due to CA and CONV treatments and median scores indicated the overall effects on five soil functions. Across the environmental zones, CONV had overall negative effects on soil functions with a median score of 0.50 whereas CA had overall positive effects with median score ranging from 0.80 to 0.83. The study proposes the need for field-based investigations, policies and subsidy support to benefit from CA adoption to enhance the five soil functions.Unión Europea 635201Unión Europea 652615Unión Europea 68927

Roles and Interests of Mycorrhizal Communities in Agricultural and Agroforestry Practices

Mycorrhizal communities are recognized as consisting of powerful microbes that may contribute to plant nutrition and health. They are of major interest in the practical context of finding solutions to production and environmental problems in agriculture. In the context of global change and decrease of nutrient supply, research works on the role of mycorrhizal communities in drought stress responses and nutrient uptake would be welcome. Although the biology of mycorrhizal fungi has been widely studied, there is a lack of knowledge on the impact of agricultural and agroforestry practices on these microbes. Indeed, the role of agricultural practices on mycorrhizal networks is still not well understood. Contributions likely to increase our knowledge on the impact of agroecological practices, in agriculture and agroforestry, on mycorrhizal networks are requested. Such practices include plant cover, diversification of crop succession, mixed crops, and conservation tillage. Identifying practices that may help to develop soil mycorrhizal community networks is of major interest

Observer des plantes à différentes longueurs d’onde pour mieux étudier les maladies transmises par les sols

https://theconversation.com/observer-des-plantes-a-differentes-longueurs-donde-pour-mieux-etudier-les-maladies-transmises-par-les-sols-18657

Biodiversité fonctionnelle fongique : indicateur d'écotoxicité des métaux dans les sols ?

ROUEN-BU Sciences (764512102) / SudocSudocFranceF

De nouvelles technologies pour mieux détecter les maladies des plantes

https://theconversation.com/de-nouvelles-technologies-pour-mieux-detecter-les-maladies-des-plantes-145206De nouvelles technologies pour mieux détecter les maladies des plantes https://theconversation.com/de-nouvelles-technologies-pour-mieux-detecter-les-maladies-des-plantes-145206 1/4 L'expertise universitaire, l'exigence journalistiqu

Relationship between initial soil microbial diversity and the quality of exogenous organic matter: Effect on carbon stability of Soil Organic Matter

International audienceIn a context of global climate change, carbon management is an important point. Therefore, the strategy of sequestration of stable carbon in agricultural soils is the preferred option to offset emissions of greenhouse gases. In addition, from an agronomic point of view, changing agricultural practices by Exogenous Organic Matter (EOM) inputs, allows to significantly increase the organic carbon storage in soils.The objectives of our work were to understand: i) the respective relationship between the chemical composition of Organic Waste Products (OWP) and the diversity of soil microbial communities, and ii) the effect of those communities on the degradation of organic matter.This study concentrated mainly on four organic waste products: green waste compost, green waste-sludge compost, sewage sludge and cattle manure mature. The degradation of these OWP was studied by incubation at 20°C for 6 months, in two agricultural soils that have different microbial diversity status (Permanent Grassland PG, Arable Cropping AC). The OWP were made at constant carbon (4g carbon/kg dry soil).The physicochemical characterization of the organic matter of OWP and the soils was conducted to determine the total carbon and total nitrogen. Furthermore, thermal analysis has been proposed in order to assess their level of stability. Soil functional activity was measured through i) enzymatic activities including cellulase, xylanase, lipase, and alkaline phosphatase and ii) potential metabolic activity of heterotrophic bacteria with BiologTM ecoplate well system (average well color development (AWCD) and Richness (R)). In parallel, the dynamic of carbon mineralization was followed.Thermogravimetric analysis showed different levels of stability between OWP. Indeed, the weight losses between 200 and 760°C was higher in order of importance, for the sewage sludge, green waste-sludge compost, cattle manure and green waste compost. These weight losses occurred mainly in two steps. At 210–320°C range, the peak observed was attributed to the combustion of carbohydrates, which were more important for sewage sludge (41%), even though the thermal degradation of the aromatic structures occurred at 400–679°C for green waste compost (16%). Moreover, the combination of these two results seemed to indicate that organic matter is slightly more transformed in the first case than in the second. These results are in agreement with those obtained on the Van Soest biochemical fractionation of OWP, and with Organic Matter Stability Index (OMSI).Preliminary results during the first 21 days of incubation indicated changes in microbial functions depending on the time of incubation, the nature of OWP and the initial status of microbial diversity of soils. Indeed, the monitoring of the measured variables often indicated significant changes at 8 and 14 days of incubation. Moreover, the microbial community from PG soil was more active than from AC one, if we consider the functional activities or the carbon mineralization. Finally, adding OWP favored carbon mineralization in both soils. However, the effects on microbial functions were more nuanced. In fact, in PG soils, the EOM input did not change functional activities. In contrast, in AC modality, the metabolic activity was generally higher when OWP were added. However, the enzymatic activities were not stimulated by inputs. Green waste-sludge compost was hardly degraded by cultivable bacteria. We found that the metabolic activity (R, AWCD) was low and equivalent to the AC soil. The same result was observed with the dynamic of carbon mineralization.In summary, the first results of this study show that depending on the composition of the microbial communities of both soils and composition of the OWP, microbial activities seem to respond differently and more significantly for the AC soil and for stable OWP. To complete our study, it is necessary to conduct additional measurements on microbial community such as abundance (total DNA, carbon biomass) and diversity (bacterial and fungal DNAs) up to 6 months of soil incubation

Rhizodeposition et stimulation des microorganismes du sol : étude de la variabilité des activités enzymatiques du sol et de la rhizodéposition N, C sous différent couverts de légumineuses.

National audienc

Soil and crop cover: a potential resource of biocontrol agents against pea root rot caused by Aphanomyces euteiches

International audienc

Impact de la rhizodéposition des légumineuses à graines et des légumineuses fourragères sur la dynamique du N, C, P dans les sols et sur les communautés microbiennes du sol (RhizoComm).

International audienc

Identification of Tomato Ve1 Homologous Proteins in Flax and Assessment for Race-Specific Resistance in Two Fiber FlaxCultivars against Verticillium dahliae Race 1

International audienceIn the last decade, the soil borne fungal pathogen Verticillium dahliae has had an increasingly strong effect on fiber flax (Linum usitatissimum L.), thus causing important yield losses in Normandy, France. Race-specific resistance against V. dahliae race 1 is determined by tomato Ve1, a leucine-rich repeat (LRR) receptor-like protein (RLP). Furthermore, homologous proteins have been found in various plant families. Herein, four homologs of tomato Ve1 were identified in the flax proteome database. The selected proteins were named LuVe11, LuVe12, LuVe13 and LuVe14 and were compared to other Ve1. Sequence alignments and phylogenic analysis were conducted and detected a high similarity in the content of amino acids and that of the Verticillium spp. race 1 resistance protein cluster. Annotations on the primary structure of these homologs reveal several features of tomato Ve1, including numerous copies of a 28 amino acids consensus motif [XXIXNLXXLXXLXLSXNXLSGXIP] in the LRR domain. An in vivo assay was performed using V. dahliae race 1 on susceptible and tolerant fiber flax cultivars. Despite the presence of homologous genes and the stronger expression of LuVe11 compared to controls, both cultivars exhibited symptoms and the pathogen was observed within the stem. Amino acid substitutions within the segments of the LRR domain could likely affect the ligand binding and thus the race-specific resistance. The results of this study indicate that complex approaches including pathogenicity tests, microscopic observations and gene expression should be implemented for assessing race-specific resistance mediated by Ve1 within the large collection of flax genotype