Root biology and agriculture ecological system - Part 2.
Program:
10:00-10:10. Welcome
10:10-10:50 Philippe Hinsinger, UMR Eco&Sols, National Research Institute for Agriculture, Food and Environment, France
Rhizosphere biogeochemistry, from the root-soil interface to global cycles
10:50-11:30. Kristian Thorup-Kristensen, Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
Improving the root zone of annual crops to develop more sustainable and climate resilient cropping systems
11:30-12:10. Xavier Draye, Earth and Life Institute – Agronomy, Université Catholique de Louvain-la-Neuve, Belgium
Beyond architecture comes hydraulics... new routes for smart soil water capture/management
12:10-13:40. Lunch Break
13:40-14:20. Doris Vetterlein, Helmholtz Centre for Environmental Research – UFZ, Department Soil System Science, Halle, Germany
Rhizosphere spatiotemporal organisation – a key to rhizosphere function
14:20-14:50 Guillaume Lobet, Earth and Life Institute – Agronomy, Université Catholique de Louvain-la-Neuve, Belgium
Computational approaches to better understand how local root anatomies influence global root system conductivities
14:50-15:20. Pierre Delaplace, Gembloux Agro-Bio Tech, Université de Liège, Belgium
Mechanistic vs realistic: An impossible love story in the root system ecophysiology world ?
15:20-15:40. Mareike Weule, Research associate at Fraunhofer‐Institut IIS, Fürth, Germany
Automated analysis of root growth development using X-ray technology
15:40-16:00. Short talk for PhD student
16:00-16:10 Closing remarks
Abstract
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Philippe Hinsinger, UMR Eco&Sols, National Research Institute for Agriculture, Food and Environment France
Rhizosphere biogeochemistry, from the root-soil interface to global cycles
The biogeochemical cycles are amongst the global Earth system processes that have been the most profoundly altered by Human activities, including agriculture in the first place. For instance, the chemical flows of nitrogen and phosphorus have been shown to get beyond the so-called planetary boundaries. Plants and soils play a key role in regulating those cycles across scales, from the rhizosphere to the planet. Further understanding of the rather unique rhizosphere biogeochemistry is needed, as well as that of their consequences at larger spatial and temporal scales. Roots can indeed have a dramatic impact on the fate of nutrients as a direct consequence of their nutrient uptake capacity. This can be illustrated through the root-induced weathering of silicate minerals and its impact on the biogeochemical cycle of potassium. In addition, roots can release large amounts of carboxylates or enzymes and considerably alter soil pH, either themselves or through the stimulation of their rhizosphere microbiome. Roots have thereby evolved diverse mining strategies that rely on combinations of such rhizosphere processes occurring over short spatial and temporal scales around living roots. These can result in dissolution/precipitation of carbonate or phosphate minerals and rocks in the rhizosphere and, ultimately, contribute to soil formation and nutrient cycling at large scales. Last but not least, roots are a major source of carbon compounds being delivered to the soil through a range of processes, including exudation and, more generally, rhizodeposition. In the current context of climate change, one also needs to account for such rhizosphere processes occurring not just in the topsoil but also at depth, as roots can thereby make a major contribution to soil carbon sequestration and, ultimately, to the mitigation of climate change.
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Kristian Thorup-Kristensen, Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
Improving the root zone of annual crops to develop more sustainable and climate resilient cropping systems
In the search for crops “smart crops”, which can produce more with less, we need to improve the ability of crops to utilize available soil resources. In our predominantly annual cropping systems, deep rooting is severely limited. With annual crops, new root systems must be developed from the soil surface each year, and the short duration crops have limited time for deep root development. If we can increase the depth of root exploitation, it will be important for most plant nutrients, bu especially important for the use of the more mobile resources such as water and nitrogen, which are some of the most critical soil resources for crop production, resilience and the environment. We study how crop root development and subsoil exploitation can be improved. A main approach is root phenotyping to allow breeding of improved crop cultivars. Deeper rooting can also be achieved through crop species choice, crop management, crop rotations or intercropping, and such methods can be more effective than plant breeding, especially in the short term. Using plant breeding and agronomic approaches, crop rooting depth and access to subsoil resources can be improved significantly, thereby improving food production, its resilience and improving resource use efficiency. Ultimately, if more perennial crops can be introduced into our crop production systems, more further significant improvements of root system exploitation of the soil volume may be achieved.
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Xavier Draye, Earth and Life Institute – Agronomy, Université Catholique de Louvain-la-Neuve, Belgium
Beyond architecture comes hydraulics... new routes for smart soil water capture/management
Over the last ten years, an increasing number of studies have demonstrated that the modulation of root system architecture can bring significant improvement of crop performance under water deficit situations. These studies have essentially focused on maximising water uptake by means of constitutive morphological features including root angle, root length and root anatomy through their effect on root depth and the volume of soil explored. The soil-plant system, however, harbours a much wider array of features whose ecological and agronomical significance have yet to be quantified. The morphological, anatomical and physiological plasticity of roots, the many differences between root types and the hydraulic processes within the soil-rhizosphere-root system are good examples of such features. In addition, simulation studies suggest that hydraulic architecture may lead to contrasting spatial patterns of root water uptake whose consequences on the maintenance of soil water bank remain to be analyzed.
Finally, the impact of root presence in the soil on preferential water flows has been described in the past, but has not received much quantitative consideration in the current context. We believe that these bear additional levers to improve water capture by, and supply to crops, but that these paths may require novel approaches to integrate different scales and disciplines to analyse the hydraulic domain of the soil-plant system.
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Doris Vetterlein, Helmholtz Centre for Environmental Research – UFZ, Department Soil System Science, Halle, Germany
Rhizosphere spatiotemporal organisation – a key to rhizosphere function
Resilience of agricultural systems emerges from self-organized spatiotemporal pattern formation in the rhizosphere. Based on this hypothesis an interdisciplinary research project is investigating the contribution of rhizosphere processes to plant nutrient and water uptake, soil structure formation and carbon storage as well as plant health. The research is focused on joint field and lab based experimental platforms with common plant and a soil related drivers.
An overview will be provided on the conceptual approach of integrating researchers from different disciplines, the methodological advances and the strategies for data integration and for combining different scales.The importance of soil texture/structure will be addressed and the associates gaps in knowledge regarding sensing of soil properties by roots and their ability to shape their environment.
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Pierre Delaplace, Gembloux Agro-Bio Tech, Université de Liège, Belgium
Mechanistic vs realistic: An impossible love story in the root system ecophysiology world ?
Root development and functioning are highly context-dependent. Over the last ten years, we set-up various approaches to understand the mechanisms underlying those key processes in order to improve plant nutrient use efficiency. Those strategies were either basic or applied, depending on the question we wanted to address, and lead to promising developments for the scientific Community but also contrasted results.
This talk presents this timeline of experiments and reflects on the deliverables you can expect from each set-up, considering their naturalness/realism level. Negative results will also be considered as a valuable contribution to our understanding of below ground processes. Finally, recommendations will be provided in order to design relevant experiments according to (i) the hypothesis to be tested, (ii) the available equipment and related throughput, and (iii) the realism and transposability to ‘real life’ conditions.
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Mareike Weule, Research associate at Fraunhofer‐Institut IIS, Fürth, Germany
Automated analysis of root growth development using X-ray technology
During the last years, X-ray technology has been applied for non-destructive visualization of optical inaccessible structures in plants. Formerly, this technology was only used for medical imaging. Nowadays, it is used as a standard tool in industrial applications for material analysis. With X-ray computed tomography (CT) the 3D volume information of objects can be reconstructed using X-ray projections of the object from different points of view. This sensor technology allows non-destructive analysis of hidden structures like root systems in a pot or internal structures within seed material. Running these sensor systems have normally a gain in throughput. With our new integrated CT system in a controlled environment the plants can be scanned 24/7, which enables us to scan more plants. There is no user interaction needed for measuring and watering the plants. The system can measure the root growth, but also scan the above ground part of the plants. In this presentation we will demonstrate the system and its possibilities in root growth analysis. As example of showing the capabilities of the system, we scanned different maize genotypes with variation in root architecture. We used 8 genotypes with 5 replicates to analyze the root growth. For the image analysis, we used the automated imaging pipeline CTProcessing.net. Thus, we are able to monitor and control all parameters starting from the 2D imaging, corrections, normalizations, 3D reconstruction and segmentation. Having automated CT measurements and keeping track on all individual parameters with an automated data processing in the background allows bridging the gap between data and information in the future.