Améliorer la biodisponibilité du phosphore : comment valoriser les compétences des plantes et les mécanismes biologiques du sol ?

Les ions orthophosphates (Pi) représentent les seules formes de phosphore (P) utilisable par les cultures. Dans les sols, ils sont généralement présents à de faibles concentrations dans la solution, en raison des nombreux processus géochimiques contraignant leur mobilité et disponibilité. Les plantes et les micro - organismes associés, au travers de relations rhizosphériques, symbiotiques et par la prédation des populations microbiennes, modifient considérablement la quantité de P que la plante est capable d'acquérir tout au long de sa croissance (biodisponibilité). Cette revue décrit les différents processus (modifications des racines, rôle du pH, des anions organiques, des enzymes, de la microfaune et de la macrofaune) qui peuvent modifier la biodisponibilité du P dans la rhizosphère. Des pistes pour mieux valoriser le potentiel intrinsèque des végétaux et de l'écologie des organismes du sol et optimiser l'acquisition de P des cultures à partir du sol sont proposées. (Résumé d'auteur

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Publisher Copyright: © 2021, The Author(s).Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.Peer reviewe

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

Critical review of anionic exchange resin membranes for in situ measurement of ion availability and fluxes

National audienc

How are nematode communities affected during a conversion from conventional to organic farming in southern French vineyards?

The rate of conversion from conventional vineyards to organic farming practices is increasing. Organic farming improves some soil properties, although some organic practices have negative effects on soils. The objective of this work was to study the long-term effects of organic farming through the use of soil nematodes as bio-indicators of soil processes. Our experimentation was conducted in a commercial vineyard where plots belonged to two types of viticulture: conventional viticulture and organic viticulture (for 7, 11 and 17 years). The nematode community structure and nematode indices were determined. The main result was that organic practices increased soil nematode density. An increase in the available resources, as measured by a higher enrichment index (EI), led to an increase in the microbial feeder density and mainly opportunistic fungal-feeding nematodes. A greater density of plant-feeding nematodes was attributed to the presence of a grass cover. The functioning of the soil was shifted with the decomposition channel of the soil organic matter becoming more fungal than bacterial. Even though changes were observed in the nematode community structure following the conversion, the maturity index (MI), the plant-parasitic index (PPI) and the structure index (SI) remained constant. Consequently, the organic practices did not improve the soil food web length or complexity even though the biological activity, as measured by microbial biomass and total nematode density, increased

Biodiversity-based cropping systems: A long-term perspective is necessary

International audienc

How are nematode communities affected during a conversion from conventional to organic farming in southern French vineyards?

The rate of conversion from conventional vineyards to organic farming practices is increasing. Organic farming improves some soil properties, although some organic practices have negative effects on soils. The objective of this work was to study the long-term effects of organic farming through the use of soil nematodes as bioindicators of soil processes. Our experimentation was conducted in a commercial vineyard where plots belonged to two types of viticulture: conventional viticulture and organic viticulture (for 7, 11 and 17 years). The nematode community structure and nematode indices were determined. The main result was that organic practices increased soil nematode density. An increase in the available resources, as measured by a higher enrichment index (EI), led to an increase in the microbial-feeder density and mainly opportunistic fungal-feeding nematodes. A greater density of plant-feeding nematodes was attributed to the presence of a grass cover. The functioning of the soil was shifted with the decomposition channel of the soil organic matter becoming more fungal than bacterial. Even though changes were observed in the nematode community structure following the conversion, the maturity index (MI), the plant-parasitic index (PPI) and the structure index (SI) remained constant. Consequently, the organic practices did not improve the soil food web length or complexity even though the biological activity, as measured by microbial biomass and total nematode abundance, increased

How are nematode communities affected during a conversion from conventional to organic farming in southern French vineyards?

The rate of conversion from conventional vineyards to organic farming practices is increasing. Organic farming improves some soil properties, although some organic practices have negative effects on soils. The objective of this work was to study the long-term effects of organic farming through the use of soil nematodes as bioindicators of soil processes. Our experimentation was conducted in a commercial vineyard where plots belonged to two types of viticulture: conventional viticulture and organic viticulture (for 7, 11 and 17 years). The nematode community structure and nematode indices were determined. The main result was that organic practices increased soil nematode density. An increase in the available resources, as measured by a higher enrichment index (EI), led to an increase in the microbial-feeder density and mainly opportunistic fungal-feeding nematodes. A greater density of plant-feeding nematodes was attributed to the presence of a grass cover. The functioning of the soil was shifted with the decomposition channel of the soil organic matter becoming more fungal than bacterial. Even though changes were observed in the nematode community structure following the conversion, the maturity index (MI), the plant-parasitic index (PPI) and the structure index (SI) remained constant. Consequently, the organic practices did not improve the soil food web length or complexity even though the biological activity, as measured by microbial biomass and total nematode abundance, increased