Papers by Christophe Jourdan
Nutrient and carbon dynamics in agroecosystems from a rhizosphere biogeochemistry perspective
HAL (Le Centre pour la Communication Scientifique Directe), Sep 26, 2018
Contribution of tree and crop roots to soil carbon stocks in a Sub-Sahelian agroforestry parkland in Senegal
Agriculture, Ecosystems & Environment, Aug 1, 2023
Integration of biotechnologies for rubber tree improvement. What about rootstock clones
Breeding and dissemination of planting material for rubber plantations are closely linked to prop... more Breeding and dissemination of planting material for rubber plantations are closely linked to propagation methods. Since the progress made by shifting from multiplication by seed to propagation by budding, the development of new techniques, such as micropropagation, has been awaited. New varietal types such as self-rooted plants, rejuvenated budded clones, genetically modified organisms, and rootstock material were developed from microcutting and somatic embryogenesis techniques at the research level. The development of rootstock clones adapted to the selected scion clones is likely to be the most promising approach to improve significantly rubber tree for various agronomical traits such as tree growth, tolerance to wind damage, root diseases and drought conditions. Both the recalcitrance to micropropagation techniques and the long-term process of evaluation and clone recommendation have hampered rapid progress in rubber tree, but nowadays, new research advances have to be considered. The root architecture modelling, genomics and post-genomics approaches, molecular breeding have been integrated to optimize the prediction in genetic improvement programme of several estate crops like oil palm. The integration of biotechnologies for rubber tree improvement must be considered to accelerate the development of rootstock material. That will be decisive for assessing the degree to which new technologies are taken on board in modern rubber growing. The involvement of growers and agro-industrialists. (Resume d'auteur)
Le pH en image. Cartographie spatio-temporelle du pH dans la rhizosphère à l’aide de capteurs fluorescents, les optodes
HAL (Le Centre pour la Communication Scientifique Directe), Oct 10, 2016
Agronomic performances and environmental impact of biodegradable films as an alternative to polyethylene mulches in vineyards
HAL (Le Centre pour la Communication Scientifique Directe), Sep 15, 2014
HAL (Le Centre pour la Communication Scientifique Directe), Jun 20, 2022
HAL (Le Centre pour la Communication Scientifique Directe), Jul 17, 2022
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Root distributions and traits in a semi-arid agroforestry parkland dominated by Faidherbia albida: potential impacts on soil C and nutrients stocks?
Impact of soil depth and plant species on root litter decomposition kinetics in a sub-sahelian agroforestry parkland
HAL (Le Centre pour la Communication Scientifique Directe), Aug 23, 2021
Nutrient cycling in agroecosystems – a rhizosphere biogeochemistry perspective
HAL (Le Centre pour la Communication Scientifique Directe), Nov 6, 2016
Horizontal and vertical variations of root distribution and traits, soil physical, chemical and microbial properties associated with CNP cycles in a young alley-cropping system under Mediterranean climate
HAL (Le Centre pour la Communication Scientifique Directe), May 16, 2022
Root distribution and traits assessment according to depth in a subsahelian agroforestry system and potential impact on soil C stocks
HAL (Le Centre pour la Communication Scientifique Directe), Jun 26, 2022
Mission to the RSUP Pulau Burung coconut plantation (Sumatra/Indonesia) 3rd November to 14th December 1997: Research on the factors limiting the yields of the PB121 hybrid coconut variety
This joint mission by an entomologist and a physiologist specialized in the study of root systems... more This joint mission by an entomologist and a physiologist specialized in the study of root systems, undertaken in November and December 1997, confirmed that attacks by Sufetula caterpillars are partly responsible for the low coconut yields at RSUP in Pulau Burung. Indeed, large excavations around the foot of high-yielding and poor-yielding 10-year-old palms revealed limited lengthwise growth of the roots: 1 to 3 m, rarely more, as opposed to 7 to 9 m for palms of the same age under non-limiting conditions. The root elongation rate seems to be very slow. The number of primary roots is abnormally high, by successive reiterations .. Moreover, it is surprising to see the existence of a dry zone stretching for a radius of 80 cm around the stem and up to 30 cm deep, whereas the water table is only 1 m down. It is precisely in that dry zone that most of the tertiary and quaternary roots, the most absorbent roots in the system, are found. Lastly, the dry zone has been observed just beneath the stem, down to a depth of 80 cm in some palms, within the plot. There is also severe soil erosion, following heavy rainfall, in a radius of 2 m around the stem. The erosion is combined with natural compaction of the peat, all of which goes to form a characteristic mound around the base of the coconut palms. This leads to exposure of mostly absorbent roots near the surface, which then dry out in the sun and are consequently more vulnerable to caterpillar attacks. Be that as it may, the caterpillars of this species are most probably not responsible for the substantial heterogeneity seen in coconut palm growth; it is mainly induced by other factors, such as the level of the water table. The heterogeneity is seen in the existence of very tall palms ( over 7 m tall), medium-sized palms (5 to 6 m) and smaller palms (2 to 3 m). All three of these categories are attacked to varying degrees by the caterpillars, which partly prevents a correlation being established between the caterpillar attack rates and the number of nuts. However, it was possible to show a good triangular relation between coconut palm height, the fresh weight of their roots and the number of nuts borne by the palms
Visit report to the RSUP Pulau Burung (Indonesia) plantation. Analysis of root growth on coconut palms subjected or not to Sufetula sunidesalis attacks. 16th November - 30th November 1998
Les racines des cocotiers de la plantation de RSUP sont soumises a de severes attaques de la part... more Les racines des cocotiers de la plantation de RSUP sont soumises a de severes attaques de la part des chenilles de #Sufetula sunidesalis#, qui penetrent a une profondeur de 60 cm et devorent les tissus pres de l'apex des racines primaires, secondaires et tertiaires, entrainant leur mort. Les objectifs de la mission etaient les suivants : rassembler les donnees de croissance des racines a partir des rhizotrons installes l'annee precedente, installer de nouveaux rhizotrons au pied de cocotiers plus jeunes et demonter les vieux, controler les observations d'excavation du systeme racinaire dans l'essai RS CC 07 et developper la methode de mesure de la biomasse racinaire en champ, visiter les essais agronomiques et entomologiques et collecte des donnees pour analyse a Montpellier
Etude de la croissance des racines du cocotier à partir de données rhizotrons au Vanuatu et en Indonésie : Centre Agronomique de Recherche et de Formation du Vanuatu (CARFV); RSUP Pulau Burung Coconut Plantation, Juillet - Août 1998
Cette etude s'inscrit dans le cadre de l'ATP n. 10/96 "Developpement d'un modele... more Cette etude s'inscrit dans le cadre de l'ATP n. 10/96 "Developpement d'un modele physiologique integrant la dimension architecturale des plantes pour la simulation de la croissance et de la production du palmier a huile et du cocotier". Les observations pour le Vanuatu se sont deroulees au CARFV pendant plus d'un an de mars 97 a mai 98. En Indonesie, les observations sont en cours. Il s'agit d'etudier les parametres de croissance des racines des arbres soumis aux attaques ou non de Sufetula, et des bons ou mauvais producteurs
Rapport de visite à la station de recherche sur le palmier à huile (SRPH) de POBE au Bénin du 17 au 28 avril 2000 : Appui à la thèse de Leifi Nodichao "Tolérance à la sécheresse chez le palmier à huile : biodiversité racinaire et absorption potassique
Plant and Soil, Oct 15, 2022
In agroforestry systems, the root distributions and properties of the annual and perennial vegeta... more In agroforestry systems, the root distributions and properties of the annual and perennial vegetation are poorly known, although they are recognized for fostering soil carbon (C) stocks through annual root-derived C inputs and by altering microbial activity. This study aimed to evaluate the potential contribution of roots from the understory vegetation strip (UVS) and the crop to top-and subsoil C stocks (0-100 cm) to a 3-year-old agroforestry system of the alley-cropping type. Methods Root biomass, chemical composition, functional traits and anatomical structure were assessed in parallel to a characterization of soil physicochemical
Characterization of surface water-groundwater relations in an agrosystem with strong climatic constraints in the central-western groundnut basin : case of the Sob and Diohine watersheds in the Niakhar Opse (Senegal)
HAL (Le Centre pour la Communication Scientifique Directe), 2020
Impact of trees on soil characteristics and root litter decomposition as a function of soil depth in a sub-sahelian agroforestry ecosystem dominated by Faidherbia Albida
HAL (Le Centre pour la Communication Scientifique Directe), Aug 23, 2021
Plant and Soil, Apr 17, 2021
Background and aims Root biomass is one of the most widely used parameters to characterise root g... more Background and aims Root biomass is one of the most widely used parameters to characterise root growth and belowground carbon stock. Our aim was to define a standard method to estimate the root biomass of young and adult oil palm trees in commercial plantations. Methods Three methods based on the sampling excavation volume were compared using the same sampled tree. Work time and the number of workers required for each operation were recorded. We compared two large excavation volumes based on Voronoi tessellation and the standard root auger coring method in one 2year-old and one 16-year-old commercial oil-palm plantation in Benin, West Africa. Results Oil palm total root biomass was estimated at 0.84 and 22.23 Mg ha −1 in the 2-year-old and 16-yearold plantation, respectively. Compared to the reference method, the simplified Voronoi trench method estimated slightly higher (+5%) and lower (−17%) total root biomass with no significant differences but required 2 and 3 times more labour time, respectively, while the auger method estimated significantly lower (−23% and − 53%) total root biomass in the 2-year-old and 16-yearold plantation, respectively. Coarse and fine root biomass were significantly higher under the windrow than under the footpath zones. Conclusion The simplified Voronoi trench method required twice as much labour time as the auger method but was most efficient way to estimate oil palm total root biomass, irrespective of the age of the plantation.
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Papers by Christophe Jourdan