Eric Blanchart

Institute of Research for Development | IRD · 210 - Functional Ecology and Biochemistry of Soils and Agroecosystems (Eco&Sols)

Upland rainfed rice cropping in the highlands of Madagascar is strongly limited by poor Ferralsol mineral fertility. There is an urgent need to identify efficient and sustainable fertilization practices that improve soil fertility without inducing pest proliferation. For that purpose, using a field trial for 2 successive years, we tested the effect...

Soils are now recognized as key components in the design of sustainable agricultural practices within the agroecological framework. They are the place of many ecological functions achieved by living organisms interacting with each other and which support the sustainable provision of agrosystem services. In the context of the transformation of agric...

While long-term organic fertilizer (OF) applications tend to decrease copper (Cu) and zinc (Zn) availability in agricultural soils, earthworm bioturbation has been reported to have the opposite effect. Thus, the consequences of OF amendments in earthworm-inhabited soils on Cu and Zn bioavailability to earthworms are still under debate. Here, we ass...

Les sols hébergent une importante biodiversité. Ils sont essentiels pour nourrir l'humanité et jouent un rôle fondamental dans les cycles biogéochimiques de la planète. Alors qu'à l'échelle du globe, un tiers des sols sont dégradés, comprendre les processus écologiques qui s'y déroulent pour mieux les préserver et les restaurer est un enjeu majeur....

A basic understanding of the fertilization resources (FR) characteristics is required to drive soil functions following the FR application, and to improve crop productivity. The datasets presented include the FR characteristics, i.e. their nutrient contents and biochemical quality, and their effects on soil in carbon (C) and nitrogen (N) mineraliza...

Les sols hébergent une importante biodiversité. Ils sont essentiels pour nourrir l'humanité et jouent un rôle fondamental dans les cycles biogéochimiques de la planète. Alors qu'à l'échelle du globe, un tiers des sols sont dégradés, comprendre les processus écologiques qui s'y déroulent pour mieux les préserver et les restaurer est un enjeu majeur....

Aim Macroinvertebrates comprise a highly diverse set of taxa with great potential as indicators of soil quality. Communities were sampled at 3,694 sites distributed world‐wide. We aimed to analyse the patterns of abundance, composition and network characteristics and their relationships to latitude, mean annual temperature and rainfall, land cover,...

Agroforestry systems (AFS) are recognized as one of the practices with high potential to store carbon in soils. In the Itasy region, AFS were introduced to improve farmers’ livelihoods by diversifying income sources and to address problems related to soil degradation. Previous studies in the region have shown the potential of AFS to store organic c...

Within agroforestry systems, trees greatly contribute to soil carbon (C) sequestration. We still know little about how this contribution varies according to tree species. Here, we quantified the soil C content derived from three main tree species, Eucalyptus robusta, Coffea arabica and Citrus clementina, used in rainfed rice-based agroforestry in t...

Agricultural practices significantly affect soil biodiversity and functions, altering biogeochemical cycles and potentially compromising food production. Increased employment of sustainable agricultural practices is of growing policy concern and requires a better understanding and quantification of how agriculture affects soil functioning. We condu...

Plant diversification is one of the main ways to ecologically intensify agroecosystems to improve their sustainability and resilience. Rotations and/or a mixture of crops can mitigate pest and weed infestation, reduce diseases , and improve soil fertility and crop productivity. However, rainfed rice yields in the Malagasy highlands remain low despi...

A positive Priming Effect (PE) is defined as an acceleration of the decomposition of soil organic matter (SOM) by a fresh organic matter (FOM) input. But in the literature many studies present this phenomenon as an extra loss of carbon from SOM to the atmosphere. SOM is actually a mixture of pools with different turnover rates, and microorganisms g...

Plant diversification through crop rotation or agroforestry is a promising way to improve sustainability of agroecosystems. Nonetheless, criteria to select the most suitable plant communities for agroecosystems diversification facing contrasting environmental constraints need to be refined. Here, we compared the impacts of 24 different plant commun...

Free-living nematodes have beneficial effects on plant growth and nutrition. Exploring how agricultural practices modulate these beneficial effects is still challenging. A study was conducted in Ferralsols from Madagascar from one unmanaged grassland and 16 upland rainfed rice fields, representative of different agricultural practices: rotation, ag...

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 provid...

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 provid...

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 provid...

With the development of agroecology, soil plays a particularly important role in the design of sustainable agricultural practices. The soils are the place of many processes operated by living organisms interacting with one another. Soil biodiversity performs various processes which determine the main aggregated functions and finally agrosystem serv...

We conducted a greenhouse experiment in mesocosms for 28 days to assess the effects of the endogeic earthworm Pontoscolex corethrurus on plant-available soil phosphorus (P) and rice (Oryza sativa) P nutrition in a Malagasy Ferralsol. To assess plant-available soil P, we determined the L-value by measuring the specific activity of P taken up from th...

Agroecology is based on the optimization of ecological processes occurring in agrosystems, especially by improving beneficial interactions among organisms. Recent studies have provided evidence that the ability of plants to interact with free-living soil organisms can be influenced by plant breeding. The upland rice breeding programme in the Highla...

The effects of earthworm inoculation and cropping systems on upland rice systems were examined over a four-year period in the Highlands of Madagascar. Each year, endogeic earthworms Pontoscolex corethrurus (Rhinodrilidae) were inoculated (EW+) at a density of 75 ind m−2 or were not inoculated (EW0). Inoculation was tested in three cropping systems:...

The Paris Climate Agreements and Sustainable Development Goals, signed by 197 countries, present agendas and address key issues for implementing multi-scale responses for sustainable development under climate change—an effort that must involve local, regional, national, and supra-national stakeholders. In that regard, Continental Carbon Sequestrati...

Soil aggregation and its effects on soil C storage have been addressed in thousands of research articles over the last 40 years. Research has been mostly focused on the resistance of aggregates to mechanical disruption and the role of organic matter in aggregate stabilization. On the other hand, relatively little attention has been paid to identify...

Soil ag gre ga tion Soil or gan isms C cy cling A B S T R A C T Soil ag gre ga tion and its ef fects on soil C stor age have been ad dressed in thou sands of re search ar ti cles over the last 40 years. Re search has been mostly focused on the re sis tance of ag gre gates to me chan i cal dis rup tion and the role of or ganic mat ter in ag gre gate...

Une belle exposition montée en 1990, exposée en 1998 lors du XVIe Congrès Mondial de Science du Sol à Montpellier, a continué de voyager après les années 2000. Elle s'est retrouvée à Alès en 2018 pour une exposition pour les jeunes et grand public. Deux scientifiques du sol, invités à donner leur opinion sur le contenu des panneaux, ont réalisé com...

Avec le développement de l'agroécologie, le sol prend une place importante dans la réflexion sur la mise en place de pratiques agricoles durables. Le sol est le siège de nombreux pro-cessus opérés par des organismes vivants agissant de façon interactive. Ces processus sont indispensables pour la durabilité des services rendus par les agrosystèmes....

La sensibilisation du grand public, et en particulier des plus jeunes, à l’importance des sols pour notre environnement et le fonctionnement de nos sociétés, est une des clefs de leur préservation. Le programme de recherche GESSOL « Gestion durable des sols » du ministère en charge de l’écologie a élaboré et diffusé, entre 2010 et 2018, une brochur...

Cover photo

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, a...

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

This PDF file includes: Materials and Methods Supplementary Text Figs. S1 to S6 Tables S1 to S4 References

To optimize the nutrient management of upland rice production on tropical ferralsols, a greenhouse experiment was established using the multi-nutrient omission approach. A reciprocal soil origin-rice cultivar transplant experiment was also conducted to better understand the relative contributions of the soil origin and the rice cultivar in rice nut...

In Mid-West Madagascar, rainfed rice cultivation expanded on uplands in response to lowlands saturation. Yet, rice yields remain low due to low soil fertility, high pest, weed and disease pressure and little access to external inputs. Increasing managed biodiversity within crop rotations may help improving yield while contributing to restore ecolog...

During collecting trips to Madagascar in the last decade several Acanthodrilidae sensu lato species were collected. The newly acquired material expresses high variability of the excretory system containing meroic, holoic vesiculate and holoic avesiculate species. The possible relationships of the Malagasy acanthodrilids is discussed and five specie...

Revealing belowground-aboveground relationships (BAR) is essential to drive ecological processes to address agriculture dysfunctions, especially in the management of aboveground plant diseases. Earthworms are one of the most important soil organisms involved in BAR, and silicon (Si) has been identified as a crucial element regulating aboveground pl...

L’agroécologie est, de manière croissante, évoquée au cœur des discussions internationales sur le devenir des systèmes agricoles et alimentaires dans le monde, en apparaissant comme une des réponses pertinentes aux grands défis globaux en matière de développement économique et social et d’environnement, largement reflété́ dans les Objectifs de Déve...

Aims: In Madagascar, agroecological practices to increase and sustain upland rice productivity are based on an intensification of soil ecological processes. Study Design: The effects of earthworm presence and identity (Pontoscolex corethrurus, Dichogaster saliens, or no earthworms), residue presence and identity [Crotalaria grahamiana (Fabaceae), D...

Comment, depuis plusieurs décennies, la recherche scientifique contribue-t-elle au développement des pays du Sud ? À travers plus de 100 succès emblématiques de la recherche en partenariat, cet ouvrage nous plonge au coeur des grandes questions de développement : oeuvrer pour des sociétés plus justes, lutter contre les maladies, faire face aux risq...

En 2017-2018, en Guyane française, la réserve naturelle des Nouragues a collaboré avec l'équipe du projet LongTIme (Labex CEBA) pour favoriser le partage des recherches en cours auprès des habitants du territoire. Suivi de missions, échanges avec les chercheurs, organisation de rencontres, création d'outils pédagogiques et réalisation d'un document...

L'année 2015 a été déclarée Année Internationale des Sols par les Nations Unies. A cette occasion, un événement de sensibilisation du grand public et du jeune public, à la connaissance des sols, a eu lieu à Madagascar du 8 au 19 décembre 2015. Cette opération a été co-organisée par l'IRD (UMR Eco&Sols) et le LRI (laboratoire des RadioIsotopes de l'...

Soils are biosystems whose functions and services are determined by the dynamics and activity of living organisms and environmental parameters, whether they are natural or of anthropic origins. Soil microorganisms consist of the following four major groups of energy and nutritional activities involved in the functioning of biogeochemical cycles: ch...

Soil bacterivorous nematodes are key plant mutualists that increase nutrient availability for plants either by enhancing the mineralization of organic compounds (the “mineralization pathway”) or by increasing plant lateral root branching following shifts in internal plant metabolism, and subsequently leading to a higher volume of soil prospected by...

L’agriculture climato-intelligente (Climate Smart Agriculture) vise à lutter contre le changement climatique et à s’y adapter tout en combattant l’insécurité alimentaire. À Madagascar, différentes pratiques agricoles ont été testées depuis une vingtaine d’années par des organisations non gouvernementales et des institutions de recherche afin d’accr...

Soil bacterivorous nematodes are key plant mutualists that increase nutrient availability for plants either by enhancing the mineralization of organic compounds (the "mineralization pathway") or by increasing plant lateral root branching following shifts in internal plant metabolism, and subsequently leading to a higher volume of soil prospected by...

The priming effect (PE) in soil, when induced by a fresh carbon supply, is believed to result from two different mechanisms, "stoichiometric decomposition" and "nutrient mining", and contributes to either long-term SOM stabilization or depletion. Understanding how to affect the balance between both mechanisms can provide valuable insight into agroe...

Climate smart agriculture is presented as a solution to alleviate food insecurity, mitigate climate change and contribute to climate change adaptation. In Madagascar, different sustainable agricultural practices were implemented in the last 20 years by many non-governmental organizations in order to increase crop yields, maintain soil fertility and...

Depuis le milieu du XX e siècle, du fait de la forte croissance démographique, les sols et la végétation des zones tropicales et méditerranéennes subissent d'importantes dégradations. Actuellement, plus de 20 % des terres cultivées sont dégradées chimiquement, physiquement et biologiquement. En effet, malgré la mise en oeuvre de grands projets tels...

The priming effect in soil is proposed to be generated by two distinct mechanisms: ‘stoichiometric decomposition’ and/or ‘nutrient mining’ theories. Each mechanism has its own dynamics, involves its own microbial actors, and targets different soil organic matter (SOM) pools. The present study aims to evaluate how climatic parameters drive the inten...

Investigation of earthworms collected in Madagascar resulted in the discovery of two new species belonging to the endemic family Kynotidae: . Kynotus sihanakus and . Kynotus sakafotsy spp. nov. In addition to the description of both new species, . Kynotus voeltzkowi Michaelsen, 1897 and . Kynotus schistocephalus Michaelsen, 1897 were recorded for t...

We tested the ability of root-adhering soils (RAS) from eight rice cultivars to attract a bacterivorous nematode (Acrobeloides sp.) living in a poor-nutrient soil in Madagascar. We showed that the ability of rice to attract bacterivorous nematodes in its rhizosphere is variable among cultivars. FOFIFA 172 was the cultivar with the highest attractio...

This poster relate how microbial (bacterial an fungal) diversity is implicated in priming effect mechanisms along two different climate gradients, allowing to discriminate annual temperature from rainfall effect, in Malagasy Highlands.

In a mesocosm field experiment in the highlands of Madagascar, we explored the potential way to manage earthworms and service plant residues in a way beneficial to rainfed rice crop production