Tantely Razafimbelo

Tantely Razafimbelo
University of Antananarivo · Laboratory for Radioisotopes

Professor

About

111
Publications
26,164
Reads
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1,811
Citations
Citations since 2016
75 Research Items
1294 Citations
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2016201720182019202020212022050100150200250300350
2016201720182019202020212022050100150200250300350
2016201720182019202020212022050100150200250300350

Publications

Publications (111)
Article
Full-text available
Upland rice production is limited by the low phosphorus (P) availability of many highly weathered tropical soils and P deficiency is likely to become increasingly limiting in future drier climates because P mobility decreases sharply with soil moisture. Good seedling root development will be crucial to cope with the combined effects of low P and wa...
Article
Accurate assessments of soil properties are required to improve fertilizer management practices for crop production. Conventional chemical analysis in the laboratory is costly and time-consuming. Soil color is related to different soil compositions, while soil magnetic susceptibility (MS) has been found to reflect the abundance of magnetic minerals...
Article
Full-text available
The extent to which the central highlands of Madagascar were once covered by forests is still a matter of debate: while reconstructing past environments is inherently difficult, the debate is further hampered by the fact that the evidence documenting land cover changes and their effects on carbon and sediment dynamics in Madagascar has hitherto mai...
Article
Full-text available
Over the past few decades, developments in remote sensing have resulted in an ever-growing availability of topographic information on a global scale. A recent development is TanDEM-X (TerraSAR-X add-on for digital elevation measurements), an interferometric synthetic aperture radar (SAR) mission of the Deutsche Zentrum für Luft- und Raumfahrt, prov...
Article
Full-text available
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...
Article
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...
Chapter
East Africa remains one of the most severely affected regions impacted by food insecurity with an increasing number of undernourished people (NEPAD 2013). The sustainable management of agricultural land and water resources is recognized as essential to achieve global food security. Almost 70% of the population of East Africa rely on agriculture (NE...
Preprint
Full-text available
The extent to which the central highlands of Madagascar were once covered by forests is still a matter of debate: while reconstructing past environments is inherently difficult, the debate is further hampered by the fact that the evidence documenting land cover changes and their effects on carbon and sediment dynamics in Madagascar has hitherto mai...
Article
Full-text available
Efficient phosphorus (P) fertilizer management is highly required for resource-limited farmers to achieve higher yields in typical P-deficient farmlands in sub-Saharan Africa. Although soil P retention has been conventionally used to estimate the possible responses to P fertilizer applied to soils, its applicability has not been clearly confirmed a...
Poster
Full-text available
Le secteur de l'agriculture, de la forêt et des autres utilisations des terres (AFOLU pour l'anglais Agriculture, Forestry and Other Land Uses) est émetteur en gaz à effet de serre mais c'est également un secteur pour lequel des investissements peuvent inverser la tendance. Pourtant les actions concrètes avec des résultats chiffrés sont rares du fa...
Article
Full-text available
Lavaka (gullies) are often considered as the prime indication of a currently ongoing human-induced environmental crisis in Madagascar's highlands. Yet, lavaka are known to have existed long before human arrival and account for the majority of the long-term sediment input into the highland rivers and floodplains. The role of anthropogenic disturbanc...
Preprint
Full-text available
Over the past decades, developments in remote sensing have resulted in an ever growing availability of topographic information on a global scale. A recent development is TanDEM-X, an interferometric SAR mission of the Deutsche Zentrum für Luft- und Raumfahrt providing near-global coverage and high resolution DEMs. Moreover, ongoing developments in...
Chapter
Full-text available
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...
Article
Full-text available
As a proximal soil sensing technique, laboratory visible and near-infrared (Vis-NIR) spectroscopy is a promising tool for the quantitative estimation of soil properties. However, there remain challenges for predicting soil phosphorus (P) content and availability, which requires a reliable model applicable for different land-use systems to upscale....
Article
Full-text available
Phosphorus (P) deficiency is a major yield constraint for lowland rice production in the tropics. As P-fertilizer resources are finite, alternative fertilizer management is needed for sustainable rice production. We examined whether farmyard manure (FYM), a major nutrient source for smallholder farms, can overcome issue in typical P-deficient lowla...
Article
Full-text available
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...
Article
Full-text available
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:...
Article
Rural development projects to develop sustainable agriculture need to be assessed before engagingsmallholder farmers at large scale. Data on agricultural systems to produce food, provide income forsmallholders and reduce greenhouse-gas (GHG) emissions are scarce in Sub-Saharan Africa countries.Here, we assessed the potential of agroecological pract...
Article
Full-text available
Currently, most rice farmers in the central highlands of Madagascar do not apply mineral fertilizer in their fields and we investigated whether a fertilizer micro-dose applied to the seedling nursery could serve as an entry point for intensification. Effects of nursery applications of a micro-dose of mineral (P and NPK) or locally produced sources...
Article
Full-text available
Laboratory visible and near-infrared (Vis-NIR) spectroscopy with partial least squares (PLS) regression can be used to determine the soil carbon (C) content, and the waveband selection procedures can refine the predictive ability. However, individually selected wavebands are not always the same depending on the location, scale, and approach. To sim...
Article
The soil map of Madagascar has not been substantially updated since the 1960s. The number of reported soil profiles that meet the criteria of the Reference Pedon Description – the highest level of data reliability used to ascertain FAO soil unit classification – is also limited for a country-scale soil map. Therefore, we conducted a soil survey in...
Article
Full-text available
Sequestration of soil organic carbon (SOC) in agricultural systems is a key indicator of soil fertility improvement and climate change mitigation at the global scale. In Madagascar, the effect of management conversion from traditional practices to agroecological ones on SOC sequestration remains unclear. The objectives of this study therefore were...
Book
Les sols sont une ressource essentielle à préserver pour la production d'aliments, de fibres, de biomasse, pour la filtration de l'eau, la préservation de la biodiversité et le stockage du carbone. En tant que réservoirs de carbone, les sols sont par ailleurs appelés à jouer un rôle primordial dans la lutte contre l'augmentation de la concentration...
Article
Full-text available
Crop production is limited by low soil fertility in sub-Saharan Africa (SSA), particularly by P deficiency due to strong fixation by Fe and Al oxyhydroxides. Organic amendments are known to increase P availability in fertilizer and in such soils by different mechanisms. This study investigated the effect of adding farmyard manure (FYM) versus miner...
Article
Full-text available
Land degradation and regeneration are complex processes that greatly impact climate regulation, ecosystem service provision and population wellbeing and require an urgent and appropriate response through land use planning and interventions. Spatially explicit land change models can greatly help decision makers, but traditional regression approaches...
Article
Soil color has been conventionally measured using a Munsell soil color chart. Recently launched colorimeters can also measure the color of an object at a reasonable cost. This study was undertaken to evaluate to what extent such low-cost colorimeters (< 500 USD) can be useful for soil color analysis in the laboratory as compared with conventional c...
Article
Full-text available
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...
Article
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...
Technical Report
Full-text available
Report on the views of stakeholders for potential for SOC management to contribute to SOC sequestration for climate change mitigation and adaptation and for the achievement of SDGs, including how these measures can be implemented, which barriers may constrain this, and which knowledge gaps need to be filled.
Technical Report
Full-text available
Report on the key barriers and solutions for the implementation of SOC sequestration options across different geographic zones and what knowledge gaps need to be filled to overcome barriers.
Article
Iron (Fe) toxicity is one of the major mineral disorders affecting rice (Oryza sativa L.) production in Madagascar. This study aimed at linking physiological and agronomic responses of diverse rice genotypes to Fe resistance mechanisms with different nutrient management practices. Twenty‐three local and exotic rice varieties were grown in Fe‐toxic...
Article
Full-text available
As a laboratory proximal sensing technique, the capability of visible and near-infrared (Vis-NIR) diffused reflectance spectroscopy with partial least squares (PLS) regression to determine soil properties has previously been demonstrated. However, the evaluation of the soil phosphorus (P) content—a major nutrient constraint for crop production in t...
Article
Land management and global warming affect the dynamics of soil organic matter (SOM) and nutrients such as nitrogen (N) and phosphorus (P). The effects depend on the type of SOM and on the temperature sensitivity of the SOM mineralization. There is insufficient data on tropical soils, which generally have low nutrient availability, to be able to pre...
Article
Full-text available
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...
Article
Full-text available
Aims Phosphorus (P) deficiency is a major constraint for rice production in the tropics. Field-specific P management is key for resource-limited farmers to increase yields with minimal inputs. We used soil P fractionation analysis to identify the relevant factors controlling P uptake and the responses to P fertilization of rice in flooded and highl...
Article
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...
Article
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'...
Article
La pauvreté du sol en éléments nutritifs disponibles pour les plantes est l’un des facteurs responsables d’une production agricole faible dans les Hautes Terres de Madagascar. La fertilité du sol et la production agricole peuvent être améliorées par le recyclage des biomasses végétale et animale. Nous avons testés deux options techniques basées sur...
Article
Full-text available
Decision-makers need readily accessible tools to understand the potential impacts of alternative policies on forest cover and greenhouse gas (GHG) emissions and to develop effective policies to meet national and international targets for biodiversity conservation, sustainable development and climate change mitigation. Land change modelling can supp...
Conference Paper
Full-text available
Les chercheurs de l'Initiative "4 pour 1000" réunis à Sète les 7 et 8 novembre 2018 lors de l’atelier "La recherche française autour du programme international de recherche de l’initiative 4 pour 1000 : les sols pour la sécurité alimentaire et le climat" ont lancé un appel pour un "programme scientifique ambitieux" pour la mise en œuvre du volet re...
Article
Full-text available
Comprendre les savoirs, savoir-faire et pratiques des paysans reste indispensable pour conduire des 17 programmes de développement agricole efficients et des recherches appropriées. Pourtant, peu d'efforts ont été 18 effectués pour étudier les savoir-faire locaux sur la gestion de la fertilité des sols au Lac Alaotra, Madagascar. 19 Cette étude a p...
Article
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...
Article
Organic carbon saturation in soils refers to the theoretical maximum soil organic carbon (SOC) that can be associated with and stabilized on fine silt plus clay particles (F < 20 μm). We reviewed the literature dealing with SOC distribution between soil fractions to evaluate carbon saturation for tropical soils and estimate the C storage potential...
Article
Full-text available
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...
Article
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...
Article
Full-text available
Comprendre les savoirs, savoir-faire et pratiques des paysans reste indispensable pour conduire des programmes de développement agricole efficients et des recherches appro-priées. Pourtant, peu d'efforts ont été effectués pour étudier les savoir-faire locaux sur la gestion de la fertilité des sols au lac Alaotra, Madagascar. Cette étude a pour obje...