121 research outputs found
Data for Water deficit and potassium affect carbon isotope composition in cassava bulk leaf material and extracted carbohydrates
No full textThis repository contains data and scripts to reproduce results that are presented in the manuscript: Van Laere, J., Merckx, R., Hood-Nowotny, R., Dercon, G. (2023) Water deficit and potassium affect carbon isotope composition in cassava bulk leaf material and extracted carbohydrates. Front. Plant Sci. 14:1222558 doi: 10.3389/fpls.2023.122255
Consumption Growth and Agricultural Shocks in Rural Madagascar
No full textThe aim of this paper is to evaluate the effect of rainfall and agricultural shocks on consumption growth in Madagascar. We are also interested in the impact of local endowments in infrastructures and social services on consumption growth. To achieve this goal, a micro model of household consumption growth is estimated thanks to household panel data collected by the Reseau des Observatoires Ruraux (ROR) between 1999 and 2004. Additional data sources include the 2001 communes census organized by the Ilo program of Cornell University. Altogether these different data sources make an unusually rich data set, at least when considered with developing country standards. We use panel data fixed effect estimation technique to remove unobserved household and community level time invariant heterogeneity. We find that production shocks have a substantial impact on consumption growth and we find sign of persistence of rainfall shocks. Roads and education seems to improve household’s consumption growth and remotness decreases it.risks, growth, poverty, Food Security and Poverty,
Evaluating mixing modelling for soil erosion hot spot identification through the use of artificial soil mixtures
No full textSoil erosion and associated sediment redistribution are key environmental problems in Central Argentina. Several land uses and managementpractices, such as intensive grazing and crop cultivation, are considered to drive and increase significantly these processes. To prove this above hypothesis, a mixing modelling approach (CSSIAR v1.00),usingEnergy Dispersive X Ray Fluorescence (EDXRF) data as fingerprint of sediment sources and sinks,is aimed to identify critical hot spots of erosion in a typical Argentinian agro-ecosystem. The study site is an Estancia Grande subcatchmentwith an area of 1235 hectares, located 23 km north east of San Luis (in the center of Argentina) and which is characterized by highly erodible Haplic Kastanozemsoils.Fil: Torres Astorga, Romina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Velasco, Ricardo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Mabit, Lionel. Organismo Internacional de Energía Atómica ; AustriaFil: Dercon, Gerd. Organismo Internacional de Energía Atómica ; Austri
C as a short-term indicator of drought stress in banana
No full textWater shortage is the most important abiotic limitation for banana. The development of climate-smart cultivars and agronomic practices is ongoing, but the process is hindered by a lack of field-applicable drought stress evaluation methods. Earlier research indicated that carbon isotope discrimination values in bulk leaf material (δ13Cbulk) could serve as a proxy for drought stress in banana. However, δ13Cbulk is a time-integrated measure of stress. Information about current and short-term conditions could be useful for early stress detection or to observe diurnal variations in stress. Phloem sap contains recently assimilated carbon. Its δ13C value (δ13Cphloem) has successfully been used as a short-term indicator of drought stress in trees. We have developed a phloem sap sampling method for banana and evaluated it in a field experiment in Arusha, Tanzania. We compared δ13Cphloem with δ13Cbulk under two different watering treatments (irrigated and rainfed) and assessed diurnal variations by sampling in the morning (08:00) and at noon (12:00). Samples were collected during the dry season. Both δ13Cbulk and δ13Cphloem were significantly affected by the watering treatments, although the effect on δ13Cphloem was greater. This indicates the more sensitive and recent nature of δ13Cphloem. In addition, δ13Cphloem differed throughout the day, while δ13Cbulk did not. δ13Cphloem was higher at noon than in the morning, likely due to the occurrence of instantaneous drought stress. This difference in δ13Cphloem between morning and noon was larger in the irrigated treatment than in the rainfed treatment. Probably, the more severe stress in the rainfed treatment already led to partial stomatal closure in the morning, resulting in a higher δ13Cphloem and a smaller difference with δ13Cphloem at noon. Such short-term diurnal variations could not be detected with δ13Cbulk. δ13Cphloem can be used as an indicator for instantaneous drought stress, creating the possibility to investigate short-term changes in stomatal dynamics at field scale and possibly the early detection of stress.sponsorship: Peaceful Uses Initiative of IAEAstatus: Published onlin
Testing a novel sensor design to jointly measure cosmic-ray neutrons, muons and gamma rays for non-invasive soil moisture estimation
No full textCosmic-ray neutron sensing (CRNS) has emerged as a reliable method for soil moisture and snow estimation. However, the applicability of this method beyond research has been limited due to, among others, the use of relatively large and expensive sensors. This paper presents the tests conducted on a new scintillator-based sensor especially designed to jointly measure neutron counts, muons and total gamma rays. The neutron signal is first compared against two conventional gas-tube-based CRNS sensors at two locations. The estimated soil moisture is further assessed at four agricultural sites, based on gravimetric soil moisture collected within the sensor footprint. Muon fluxes are compared to the incoming neutron variability measured at a neutron monitoring station and total gammas counts are compared to the signal detected by a gamma ray spectrometer. The results show that the neutron dynamic detected by the new scintillator-based CRNS sensor is well in agreement with conventional CRNS sensors. The derived soil moisture also agreed well with the gravimetric soil moisture measurements. The muons and the total gamma rays simultaneously detected by the sensor show promising features to account for the incoming variability and for discriminating irrigation and precipitation events, respectively. Further experiments and analyses should be conducted, however, to better understand the accuracy and the added value of these additional data for soil moisture estimation. Overall, the new scintillator design shows to be a valid and compact alternative to conventional CRNS sensors for non-invasive soil moisture monitoring and to open the path to a wide range of applications
2018 Technical Report - CIALCA
No full textIn 2018 marks 1 and half years into the current CIALCA phase, we can already report good progress. We entered into several co-investment agreements with scaling partners such as One Acre Fund in Rwanda (serving approx. 265,000 farmers) and the International Fertilizer Development Center in Burundi. Also, we identified 4 new PhD students from Rwanda, Burundi and eastern DR Congo that are starting their doctoral studies with Belgian Universities and have 5 additional students that conduct their PhD under the CIALCA umbrella. CIALCA also attracted considerable additional investment of USD 7.25 Million that complement or build upon previous and ongoing CIALCA work. Last but not least innovative research for development work with the Soil and Water Management & Crop Nutrition Laboratory (SWMCNL) of the Joint FAO/IAEA Division is providing insights in increase water use efficiency (WUE) to counteract drought effects on cassava production in Central Africa. We build on big data platforms such as RHoMIS and SANDMAN to better understand household heterogeneity and cassava agronomy at scale
Combining EDXRF and DRIFT-MIRS to distinguish sedimentary sources in an agricultural catchment of Argentina : Identification of suitable fingerprint elements
No full textSediment transport and the associated deposition process are key environmental problems in the semi-arid center of Argentina where the agricultural frontier and new land uses grow at the expense of native vegetation. Using sediment source fingerprinting techniques could be a way of identifying hot spots critiques of land degradation. In this research we explore the use of natural elements in soil to identify sedimentary sources in a small basin in the province of San Luis, Argentina. Soil samples were collected in different points of the basin, representing different land use (source samples) and sediments samples were taken along the stream (mixed samples). Concentrations of possible fingerprint elements were measured using EDXRF technique. Additionally, multivariate PLS analysis was applied to the infrared spectral data of the samples. With the aim of validate the procedure, two artificial mixtures were made up with known proportions of source samples. Fingerprints elements were identified obtaining with them a very good reconstruction of the source proportions in the artificial mixtures. DRIFT-MIRS PLS analysis shows a good correlation between MIRS spectra and the identified fingerprint elements.Fil: Torres Astorga, Romina Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: de los Santos Villalobos, Sergio. Consejo Nacional de Ciencia y Tecnología; MéxicoFil: Domínguez Quintero, Olgioly. Universidad Central de Venezuela; VenezuelaFil: Velasco, Ricardo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Meigikos dos Anjos, R.. Universidade Federal Fluminense; BrasilFil: Dercon, Gerd. Organismo Internacional de Energía Atómica; Austria3rd Biotechnology SummitObregonMéxicoInstituto Tecnológico de Sonor
Using sequential aerial photographs to detect land-use changes in the Austro Ecuatoriano / Utilisation de photographies aériennes séquentielles pour détecter les changements d'utilisation du sol dans l'Austro Equateur
No full textAbstract : During the last decades, there is a boom of the use of aerial photographs and remote sensing images to collect quickly accurate digital information in remote areas. Due to an easier accessibility of aerial photographs and a significant decrease of their price as well as that of the image analysis and GIS software, these techniques are becoming increasingly popular. This article presents a methodology to use Geographic Information Systems for quantifying past land use changes from aerial photographs. An application of this technique to the Austro Ecuatoriano has demonstrated that such a methodology requires that the data are both spatially and temporally compatible. In order to obtain spatially compatible data, the air photos are geo-referenced using a set of ground control points (GCP's). Our analysis shows that, if certain conditions are satisfied, GCP's obtained from topographical maps are of sufficient quality to carry out the geo-referencing procedure with a very good precision. On the other hand, temporal compatibility appears more difficult to achieve : the scale (and probably the quality) of the air photos has a significant effect on the resulting land use classification. Consequently, a calibration of the various datasources is necessary in order to avoid bias in the final results.Resume : Utilisation de photographies aériennes séquentielles pour détecter les changements d'utilisation du sol dans l'Austro Equateur. Durant les dernières décennies, il y a eu un accroissement de l'utilisation des photographies aériennes et de l'imagerie satellitaire pour récolter rapidement de l'information digitale dans un certain nombre de régions. Du fait d'une accessibilité plus grande des photographies aériennes et d'une décroissance significative de leur coût, aussi bien pour les logiciels de traitement d'image et de l'information géographique, ces techniques ont connu une popularité croissante. Cet article présente une méthodologie pour utiliser des Systèmes d'Information Géographiques pour quantifier les changements d'usages du sol passés à partir de photographies aériennes. Une application de cette technique à l'Austro Equateur a montré qu'une telle méthodologie nécessitait une compatibilité des données à la fois spatiales et temporelles. Pour obtenir des données spatialement compatibles, les photographies aériennes sont géoréférencées sur la base de l'utilisation d'une série de points de contrôle de base. Notre analyse montre que, si certaines conditions sont satisfaites, ces points de contrôle obtenus à partir de cartes topographiques sont suffisants en qualité pour exécuter une procédure de géoréférencement avec une très bonne précision. D'autre part, la compatibilité temporelle apparaît plus difficile à mettre en œuvre : l'échelle (et probablement la qualité) des photographies aériennes a un effet significatif sur la classification de l'utilisation du sol qui en découle. Par conséquent, un étalonnage des différentes sources de données est nécessaire de façon à éviter des erreurs dans les résultats.Vanacker Veerle, Govers Gérard, Tacuri Eduardo, Poesen Jean, Dercon Gerd, Cisneros Felipe. Using sequential aerial photographs to detect land-use changes in the Austro Ecuatoriano / Utilisation de photographies aériennes séquentielles pour détecter les changements d'utilisation du sol dans l'Austro Equateur. In: Revue de géographie alpine, tome 88, n°3, 2000. pp. 65-75
Distribution of nutrient pools in recently formed soils of Andean high wetlands (Huayna-Potosí, Bolivia)
No full text2 Pags. with a extended abstract. © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.In this study we attempt to evaluate the distribution of SOC, C fractions and nitrogen in glacial
deposits and high altitude wetlands to relate it with that of 137Cs as indicator of soil stability. To
this purpose topsoil sampling of moraines, colluvium and peat soil in wetlands was undertaken
during a two weeks expedition to Huayna-Potosí Glacier area in the frame of IAEA INT5153 project
in May 2017 and contents of SOC and its fractions (i.e. active and stable carbon fractions), nitrogen
and 137Cs activity (Bq kg-1) were determined.Peer reviewe
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