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Abad Chabbi - One of the best experts on this subject based on the ideXlab platform.
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Grassland-Cropping Rotations: An Avenue for Agricultural Diversification to Reconcile High Production with Environmental Quality.
Environmental management, 2015Co-Authors: Gilles Lemaire, Alan Franzluebbers, Francois Gastal, Abad ChabbiAbstract:A need to increase agricultural production across the world to ensure continued food security appears to be at odds with the urgency to reduce the negative environmental impacts of intensive agriculture. Around the world, intensification has been associated with massive simplification and uniformity at all levels of organization, i.e., field, farm, landscape, and region. Therefore, we postulate that negative environmental impacts of modern agriculture are due more to production simplification than to inherent characteristics of agricultural productivity. Thus by enhancing diversity within agricultural systems, it should be possible to reconcile high quantity and quality of food production with environmental quality. Intensification of livestock and cropping systems separately within different specialized regions inevitably leads to unacceptable environmental impacts because of the overly uniform land use system in intensive cereal areas and excessive N-P loads in intensive animal areas. The capacity of grassland ecosystems to couple C and N cycles through microbial-Soil-Plant Interactions as a way for mitigating the environmental impacts of intensive arable cropping system was analyzed in different management options: grazing, cutting, and ley duration, in order to minimize trade-offs between production and the environment. We suggest that integrated crop-livestock systems are an appropriate strategy to enhance diversity. Sod-based rotations can temporally and spatially capture the benefits of leys for minimizing environmental impacts, while still maintaining periods and areas of intensive cropping. Long-term experimental results illustrate the potential of such systems to sequester C in soil and to reduce and control N emissions to the atmosphere and hydrosphere.
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Grassland–Cropping Rotations: An Avenue for Agricultural Diversification to Reconcile High Production with Environmental Quality
Environmental Management, 2015Co-Authors: Gilles Lemaire, Alan Franzluebbers, Francois Gastal, Abad ChabbiAbstract:A need to increase agricultural production across the world to ensure continued food security appears to be at odds with the urgency to reduce the negative environmental impacts of intensive agriculture. Around the world, intensification has been associated with massive simplification and uniformity at all levels of organization, i.e., field, farm, landscape, and region. Therefore, we postulate that negative environmental impacts of modern agriculture are due more to production simplification than to inherent characteristics of agricultural productivity. Thus by enhancing diversity within agricultural systems, it should be possible to reconcile high quantity and quality of food production with environmental quality. Intensification of livestock and cropping systems separately within different specialized regions inevitably leads to unacceptable environmental impacts because of the overly uniform land use system in intensive cereal areas and excessive N-P loads in intensive animal areas. The capacity of grassland ecosystems to couple C and N cycles through microbial-Soil-Plant Interactions as a way for mitigating the environmental impacts of intensive arable cropping system was analyzed in different management options: grazing, cutting, and ley duration, in order to minimize trade-offs between production and the environment. We suggest that integrated crop-livestock systems are an appropriate strategy to enhance diversity. Sod-based rotations can temporally and spatially capture the benefits of leys for minimizing environmental impacts, while still maintaining periods and areas of intensive cropping. Long-term experimental results illustrate the potential of such systems to sequester C in soil and to reduce and control N emissions to the atmosphere and hydrosphere.
Xavier Raynaud - One of the best experts on this subject based on the ideXlab platform.
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Multifunctionality is affected by Interactions between green roof plant species, substrate depth, and substrate type
Ecology and Evolution, 2017Co-Authors: Yann Dusza, Sébastien Barot, Yvan Kraepiel, Jean-christophe Lata, Luc Abbadie, Xavier RaynaudAbstract:Green roofs provide ecosystem services through evapotranspiration and nutrient cycling that depend, among others, on plant species, substrate type, and substrate depth. However, no study has assessed thoroughly how Interactions between these factors alter ecosystem functions and multifunctionality of green roofs. We simulated some green roof conditions in a pot experiment. We planted 20 plant species from 10 gen-era and five families (Asteraceae, Caryophyllaceae, Crassulaceae, Fabaceae, and Poaceae) on two substrate types (natural vs. artificial) and two substrate depths (10 cm vs. 30 cm). As indicators of major ecosystem functions, we measured aboveground and belowground biomasses, foliar nitrogen and carbon content, foliar transpiration, substrate water retention, and dissolved organic carbon and nitrates in leachates. Interactions between substrate type and depth strongly affected ecosystem functions. Biomass production was increased in the artificial substrate and deeper substrates, as was water retention in most cases. In contrast, dissolved organic carbon leaching was higher in the artificial substrates. Except for the Fabaceae species, nitrate leaching was reduced in deep, natural soils. The highest transpiration rates were associated with natural soils. All functions were modulated by plant families or species. Plant effects differed according to the observed function and the type and depth of the substrate. Fabaceae species grown on natural soils had the most noticeable patterns, allowing high biomass production and high water retention but also high nitrate leaching from deep pots. No single combination of factors enhanced simultaneously all studied ecosystem functions, highlighting that soil–plant Interactions induce trade-offs between ecosystem functions. Substrate type and depth Interactions are major drivers for green roof multifunctionality.
Simona Consoli - One of the best experts on this subject based on the ideXlab platform.
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monitoring and modelling of soil plant Interactions the joint use of ert sap flow and eddy covariance data to characterize the volume of an orange tree root zone
Hydrology and Earth System Sciences, 2014Co-Authors: Giorgio Cassiani, Jacopo Boaga, Daniela Vanella, Maria Teresa Perri, Simona ConsoliAbstract:Mass and energy exchanges between soil, plants and atmosphere control a number of key environmental processes involving hydrology, biota and climate. The understanding of these exchanges also play a critical role for practical purposes e.g. in precision agriculture. In this paper we present a methodology based on coupling innovative data collection and models in order to obtain quantitative estimates of the key parameters of such complex flow system. In particular we propose the use of hydro-geophysical monitoring via "time-lapse" electrical resistivity tomography (ERT) in conjunction with measurements of plant transpiration via sap flow and evapotranspiration (ET) from eddy covariance (EC). This abundance of data is fed to spatially distributed soil models in order to characterize the distribution of active roots. We conducted experiments in an orange orchard in eastern Sicily (Italy), characterized by the typical Mediterranean semi-arid climate. The subsoil dynamics, particularly influenced by irrigation and root uptake, were characterized mainly by the ERT set-up, consisting of 48 buried electrodes on 4 instrumented micro-boreholes (about 1.2 m deep) placed at the corners of a square (with about 1.3 m long sides) surrounding the orange tree, plus 24 mini-electrodes on the surface spaced 0.1 m on a square grid. During the monitoring, we collected repeated ERT and time domain reflectometry (TDR) soil moisture measurements, soil water sampling, sap flow measurements from the orange tree and EC data. We conducted a laboratory calibration of the soil electrical properties as a function of moisture content and porewater electrical conductivity. Irrigation, precipitation, sap flow and ET data are available allowing for knowledge of the system's long-term forcing conditions on the system. This information was used to calibrate a 1-D Richards' equation model representing the dynamics of the volume monitored via 3-D ERT. Information on the soil hydraulic properties was collected from laboratory and field experiments. The successful results of the calibrated modelling exercise allow for the quantification of the soil volume interested by root water uptake (RWU). This volume is much smaller (with a surface area less than 2 m 2 , and about 40 cm thick) than expected and assumed in the design of classical drip irrigation schemes that prove to be losing at least half of the irrigated water which is not taken up by the plants.
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Monitoring and modelling of soil–plant Interactions: the joint use of ERT, sap flow and Eddy Covariance data to characterize the volume of an orange tree root zone
2014Co-Authors: G. Cassiani, Daniela Vanella, Maria Teresa Perri, J. Boaga, Simona ConsoliAbstract:Abstract. Mass and energy exchanges between soil, plants and atmosphere control a number of key environmental processes involving hydrology, biota and climate. The understanding of these exchanges also play a critical role for practical purposes e.g. in precision agriculture. In this paper we present a methodology based on coupling innovative data collection and models in order to obtain quantitative estimates of the key parameters of such complex flow system. In particular we propose the use of hydro-geophysical monitoring via 4-D Electrical Resistivity Tomography (ERT) in conjunction with measurements of plant transpiration via sap flow and evapotranspiration from Eddy Covariance (EC). This abundance of data is fed to a spatially distributed soil model in order to characterize the distribution of active roots. We conducted experiments in an orange orchard in Eastern Sicily (Italy), characterized by the typical Mediterranean semi-arid climate. The subsoil dynamics, particularly influenced by irrigation and root uptake, were characterized mainly by the ERT setup, consisting of 48 buried electrodes on 4 instrumented micro boreholes (about 1.2 m deep) placed at the corners of a square (about 1.3 m in side) surrounding the orange tree, plus 24 mini-electrodes on the surface spaced 0.1 m on a square grid. During the monitoring, we collected repeated ERT and TDR soil moisture measurements, soil water samples, sap flow measurements from the orange tree and EC data. We conducted a laboratory calibration of the soil electrical properties as a function of moisture content and pore water electrical conductivity. Irrigation, precipitation, sap flow and ET data are available allowing knowledge of the system's long term forcing conditions on the system. This information was used to calibrate a 1-D Richards' equation model representing the dynamics of the volume monitored via 3-D ERT. Information on the soil hydraulic properties was collected from laboratory and field experiments. The successful results of the calibrated modeling exercise allow the quantification of the soil volume interested by root water uptake. This volume is much smaller (with a surface area less than 2 m2, and about 40 cm thickness) than expected and assumed in the design of classical drip irrigation schemes that prove to be losing at least half of the irrigated water that is not uptaken by the plants.
Loic Pages - One of the best experts on this subject based on the ideXlab platform.
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Coupling reactive transport processes with root system architecture and functions: principles and application examples.
2018Co-Authors: Frédéric Gérard, Loic Pages, Philippe Hinsinger, Hannah Gatz-miller, Rénato Kerches Braghiere, Sergio Andres Bea, Klaus Ulrich MayerAbstract:We developed a novel Soil-Plant interaction model based on the coupling of a root system architecture model (ArchiSimple) with a reactive transport model (Min3P). The main novelty of this macro-scale model is to facilitate the simulation of Soil-Plant Interactions by simultaneously accounting for principles of plant biology, aqueous geochemistry and the transport of water, solutes and gases in soil. This contribution is devoted to introduce the formulation of the coupled Soil-Plant interaction model and to present two application examples highlighting the capabilities of this tool for tackling a wide range of agronomic and environmental issues. The first application focuses on phosphorus acquisition by annual plants from alkaline soils. In this case, we performed 2D simulations to investigate the role of common root processes (i.e., nutrient uptake and related pH changes) in releasing phosphate from the mineral and adsorbed pools in soil. Results are compared with observed data collected in the field and in the laboratory published in the literature . The second application is addressing the capacity of select plant species to induce the formation of calcium carbonates (and alkalization) in tropical soils through the oxalate-carbonate pathway (OCP). We simulate OCP for Iroko trees (Milicia excelsa), because these plants were shown capable of sequestering substantial amounts of calcium carbonate over the life-span of a tree (80 years) in Ivory Coast. Our process-based modeling investigation provides insight in elemental balances, most importantly the fate of carbonate produced by the decomposition of oxalate, which is not only sequestered in the form of calcium carbona
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Modelling the Interactions between root system architecture, root functions and reactive transport processes in soil
Plant and Soil, 2016Co-Authors: Frédéric Gérard, Céline Blitz-frayret, Philippe Hinsinger, Loic PagesAbstract:Soil-Plant models always oversimplified the representation of soil chemical processes or root system. The objectives of the study were (i) to present a model overcoming such limitations, and (ii) to illustrate its relevance for the modelling of Soil-Plant Interactions. We coupled a root system architecture (RSA) model with a reactive transport model using a macroscopic approach. The two models were coupled sequentially using Fortran-C++ interoperability. We used the resulting model to investigate the case of phosphorus (P) acquisition from hydroxyapatite (HA) in an alkaline soil as induced by P and calcium (Ca) uptake and pH variations in the root zone. Important model parameters were issued of the literature and we tested its sensitivity to selected soil properties. Model sensitivity to grid size and time increment was evaluated as well. The simulations revealed that HA dissolution can contribute very substantially to P nutrition in case of rhizosphere alkalisation thanks to Ca and P uptake. Root-induced acidification was much more efficient at acquiring P, suggesting that ammonium-fed plants should be more P efficient. The variations of dissolved P in the root zone partly agreed with the observations, suggesting that P release was rather controlled by desorption when alkalisation occurs. The presence of more soluble minerals as well as the increase of Ca uptake should enhance P acquisition by crops. We developed a new model and demonstrated the interest of the mechanistic description of geochemical processes with a spatially-explicit distribution of roots in soil while modelling Soil-Plant Interactions. Results of its first application to P acquisition from a mineral source in an alkaline soil were overall consistent with the literature
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ArchiSimple: a Parsimonious Model of the Root System Architecture
2012Co-Authors: Loic Pages, Delphine Moreau, Vaia Sarlikioti, Hassan Boukeim, Christophe NguyenAbstract:Models of the root system architecture are useful tools for studying the plant soil system, and many of these models have been published during the last decades. They capture several specific and interesting characteristics: (i) they simulate both the structure and spatial distribution of the root system; (ii) they allow a straightforward integration of developmental processes at the root level (e. g. elongation, branching) and their interaction with soil properties; (iii) they enable the simulation of root shoot communication via plant resources or signals. Though, few of them have been integrated into larger crop models, probably because they are not simple enough, too specific of given species or young stages, and many of them do not have an explicit connection to the shoot system and the soil. This modelling approach is an attempt to face these drawbacks. The model is built for being as generic and simple as possible, with a low number of plant parameters (only 11). It allows the root system of various plants to be simulated in relation to the soil medium and to the availability of carbon resources provided by the shoot system. It is therefore a means for studying multiple genetic and environmental Interactions in a very complex system. Several examples are given to illustrate from which data this model can be calibrated and its ability to represent some of the Soil-Plant Interactions.
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modelling of the hydraulic architecture of root systems an integrated approach to water absorption model description
Annals of Botany, 1998Co-Authors: Claude Doussan, Loic Pages, Gilles VercambreAbstract:A numerical model simulating water uptake by root systems is presented. This model can combine the locally measured root hydraulic conductances with data on the root system architecture to give a detailed description of water absorption, from the single root level to the entire root system. This is achieved by coupling a three-dimensional root system architecture model with laws describing water flow in roots. In addition to water absorption studies, the model has been developed so that it can be included in a soil water transfer simulator in order to analyse soil–plant Interactions for water uptake. The use of the model in describing water absorption is illustrated for a specific case where the hydraulic conductances are considered uniform in the whole root system. In this way, analytical results of Landsberg and Fowkes (Annals of Botany42: 493–508, 1978) are extended from the single root to the root system level. The influence of the type of root system architecture, axial conductance between crowns of maize nodal roots, transpiration in the course of the day, and non-homogeneous soil water potential on fluxes and water potentials in the root system are examined. The dynamics of the total conductance of the maize root system with plant growth is also shown for this case of uniform conductance in the root system. Cases which consider other distributions of the conductance in the root system are presented in an accompanying paper.
Gilles Lemaire - One of the best experts on this subject based on the ideXlab platform.
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Grassland-Cropping Rotations: An Avenue for Agricultural Diversification to Reconcile High Production with Environmental Quality.
Environmental management, 2015Co-Authors: Gilles Lemaire, Alan Franzluebbers, Francois Gastal, Abad ChabbiAbstract:A need to increase agricultural production across the world to ensure continued food security appears to be at odds with the urgency to reduce the negative environmental impacts of intensive agriculture. Around the world, intensification has been associated with massive simplification and uniformity at all levels of organization, i.e., field, farm, landscape, and region. Therefore, we postulate that negative environmental impacts of modern agriculture are due more to production simplification than to inherent characteristics of agricultural productivity. Thus by enhancing diversity within agricultural systems, it should be possible to reconcile high quantity and quality of food production with environmental quality. Intensification of livestock and cropping systems separately within different specialized regions inevitably leads to unacceptable environmental impacts because of the overly uniform land use system in intensive cereal areas and excessive N-P loads in intensive animal areas. The capacity of grassland ecosystems to couple C and N cycles through microbial-Soil-Plant Interactions as a way for mitigating the environmental impacts of intensive arable cropping system was analyzed in different management options: grazing, cutting, and ley duration, in order to minimize trade-offs between production and the environment. We suggest that integrated crop-livestock systems are an appropriate strategy to enhance diversity. Sod-based rotations can temporally and spatially capture the benefits of leys for minimizing environmental impacts, while still maintaining periods and areas of intensive cropping. Long-term experimental results illustrate the potential of such systems to sequester C in soil and to reduce and control N emissions to the atmosphere and hydrosphere.
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Grassland–Cropping Rotations: An Avenue for Agricultural Diversification to Reconcile High Production with Environmental Quality
Environmental Management, 2015Co-Authors: Gilles Lemaire, Alan Franzluebbers, Francois Gastal, Abad ChabbiAbstract:A need to increase agricultural production across the world to ensure continued food security appears to be at odds with the urgency to reduce the negative environmental impacts of intensive agriculture. Around the world, intensification has been associated with massive simplification and uniformity at all levels of organization, i.e., field, farm, landscape, and region. Therefore, we postulate that negative environmental impacts of modern agriculture are due more to production simplification than to inherent characteristics of agricultural productivity. Thus by enhancing diversity within agricultural systems, it should be possible to reconcile high quantity and quality of food production with environmental quality. Intensification of livestock and cropping systems separately within different specialized regions inevitably leads to unacceptable environmental impacts because of the overly uniform land use system in intensive cereal areas and excessive N-P loads in intensive animal areas. The capacity of grassland ecosystems to couple C and N cycles through microbial-Soil-Plant Interactions as a way for mitigating the environmental impacts of intensive arable cropping system was analyzed in different management options: grazing, cutting, and ley duration, in order to minimize trade-offs between production and the environment. We suggest that integrated crop-livestock systems are an appropriate strategy to enhance diversity. Sod-based rotations can temporally and spatially capture the benefits of leys for minimizing environmental impacts, while still maintaining periods and areas of intensive cropping. Long-term experimental results illustrate the potential of such systems to sequester C in soil and to reduce and control N emissions to the atmosphere and hydrosphere.