Messung und Modellierung von Bodenfunktionen
Funding: Federal Ministry of Education and Research
Project term: 2022 - 2025 (third phase)
Soil as a sustainable resource
Soil fertility is essential for sustainable plant production and, consequently, the basis for many bioeconomic value chains. From a sustainability perspective, soils need to provide not only marketable yields, but also several other ecosystem services. These include, i.e., the storage of water and carbon, filters for clean groundwater, and the maintenance of nutrient cycles and biodiversity. Sustainable soil management needs to combine and optimize all these aspects. The objective of BonaRes is to significantly expand and provide the required knowledge about the functionality of soils and to formulate reliable options for action. The BonaRes Programme currently funds ten interdisciplinary research consortia as well as the integrating BonaRes Centre for Soil Research
Funding: Forest Climate Fund, Fachagentur Nachwachsende Rohstoffe e.V. (FNR)
Project term: 01.10.2021 - 30.09.2025
Process-based quantification of CO2 fluxes of differently structured forest ecosystems at different spatial scales
Forests may be able to capture the greenhouse gas CO2 from the atmosphere, thereby mitigating climate change. The degree to which an individual forest does so can be quantified by determining its carbon balance. One of the most important uncertainties thereby is the assessment of soil respiration at a spatial scale that is relevant for the respective forest ecosystem. This is largely due to the very heterogeneous soil structure and composition.
The project aims to improve the mechanistic description of the CO2 fluxes at areas of several square meters by further developing an innovative measurement technology to determine CO2 concentrations in the soil for larger areas than currently possible. Our CO2 sensor (called line-sensor) that works in the laboratory (Lazik et al., 2019; Sever and Lazik, 2019) will be set-up for the first time in the field near the forest observation site Kienhorst (Schorfheide, Brandenburg/Germany) together with our project partners of the Eberswalde Forestry Competence Centre (LFE).
The sensor consists of flexible tube that is permeable for gases. The difference between the CO2 concentration in the soil and that inside the sensor tube, which is flushed with air, leads to a pressure change of the confined air after the tube has been closed on both sides. This pressure change, compared with a reference measurement in another tube, allows the external CO2 concentration sought to be determined. By burying such line-sensors at various depths, we will be able to measure the vertical gradient in CO2 concentrations in soils for several years, averaged along the length of the line-sensor tubes.
These line-sensors will be installed in different depths in forest soils in three stands with different vegetation types. In addition to the large-scale CO2 measurements that will enable averaging of the CO2 concentration over several meters, point measurements will be made with conventional sensors for comparison, together with measurements of the soil water status, meteorological measurements, measurements of atmospheric CO2 concentrations, and measurements of tree growth.
The data will help determine soil respiration, thereby quantifying an elusive term in the carbon balance of a forest. In combination with carbon sequestration in the biomass this will help determine whether temperate forests can be sources or sinks of carbon, and quantify the amount of carbon they absorb from or release into the atmosphere.
Funding: Deutsche Forschungsgemeinschaft - DFG
Project term: since 2022
Plot Scale Soil Diffusivity Measurement System
Soils play a crucial role in the global cycle of greenhouse gases and gas exchange between soil and atmosphere is of central importance, but its spatial and temporal dynamics are not yet understood sufficiently. Several small-scale methods exist to determine gas concentration and soil diffusivity (Ds) under laboratory conditions and in the field. However, due to the natural spatial heterogeneity of soils and the temporal dynamics of soil structure, it is hardly possible to transfer these results to the field scale.Our goal is to develop a system for measuring gas diffusivity (PeDiM) in arable soils. The new measuring system averages over local heterogeneities, and measures Ds at the field scale. It has already been shown that gas concentrations can be measured in porous media using tubular, nonporous, gas-selective membranes. The underlying measuring principle is based on the selective diffusion of the individual gas components of soil air into an arrangement of membrane tubes, which can be installed into the soil in defined length. Based on this principle, we will develop an in-situ measuring and monitoring system for Ds. Therefore, the following steps are planned: i) The new measuring principle developed in this project for quasi-continuous determination of Ds is implemented for a PeDiM prototype on laboratory scale. ii) For precise positioning of the PeDiM system in the soil, an installation device that causes minimum soil disturbance will be developed. iii) The PeDiM prototype will be tested in 2D and 3D mesocosm experiments for various substrates under controlled conditions. Parallel diffusion measurements with established measurement techniques allow the configuration of PeDiM to be optimized. iv) The optimized, final PeDiM systems will be installed in an arable field soil, and Ds will be measured in the topsoil for several months. The results will be interpreted in the context of weather-dependent soil water content changes and the dynamic changes of soil structure. Direct comparison of the PeDiM results with established, small-scale lab and profile scale diffusivity measurements will allow the investigation and confirmation of scale effects experimentally.In the end, our project will provide an innovative long-term stable measuring and monitoring system that allows the quasi-continuous measurement of Ds on the field scale for the first time. This captures an essential parameter for transport processes with respect to atmospheric boundary conditions on a scale relevant for soil-atmosphere interaction. Particularly interesting for arable soils is the completely new approach to assess the interaction between temporal dynamics of soil structure and Ds. Furthermore, continuous monitoring of Ds allows the linkage of turnover processes in soils with greenhouse gas emissions, which finally supports the development of predictive models.
, Dr. Nina Stoppe-Struck
Partner: Gottfried Wilhelm Leibniz Universität Hannover
Project term: 2022 - 2025
GLIMPSE Research consortium: „Global change impacts on microbiota-plant-soil processes relevant for water and matter cycling in agricultural ecosystems“
Subproject P3: "Root-Soil Interactions"
The project (P3) focuses on the link between root systems and soil structure with implications for water and nutrient fluxes.
Subproject P4: "Modelling""
The project (P4) focuses on dynamics of water, C, N, long-term projections and scenario testing.
Funding: Deutsche Forschungsgemeinschaft - DFG
Project term: since 2021
SoilSystems (SPP 2322) - P5: MICROHEAT
Heat dissipation and matter turnover in the course of microbial succession constrained by substrate and oxygen availability
Current challenge to increase sequestration of soil carbon (C) requires understanding the processes of C losses during microbial decomposition of diverse organic compounds. A tense competition between microbial groups for available soil organics results in a trade off between fast but less efficient or slow but more efficient metabolism of substrate. The proposed project Microheat considers that transformation of organic substrates in soil occurs in the course of multi-stage microbial succession through a sequence of decomposition stages. The duration, amplitude and dominating taxa of each successional stage as well as an efficiency of carbon utilization are dependent on substrate quality and amount and are restricted by oxygen availability. The methodological novelty and challenge of Microheat, is in estimation of the anaerobic soil volume fraction via application of X-ray CT to study the effect of oxygen diffusion constraints on C and energy use efficiency (CUE and EUE). The peculiarity of Microheat is in its conceptual view linking matter (CO2) and energy (heat) losses to microbial growth and to the range of enzyme-mediated reactions related to various stages of substrate decomposition. The Microheat project aims to relate an efficiency of microbial metabolism with heat and C losses in course of microbial succession during decomposition of organic compounds in soil. This will be done by a combination of kinetic approaches to relate matter and energy losses with 1) changes in dominating microbial populations, 2) microbial functional traits, and 3) turnover time of carbon sources. As a result, a variable CUE as a function of independently determined microbial traits will be suggested for carbon models considering dynamically changing fraction of anaerobic soil volume. The Microheat project will thus make a promising contribution to elucidating regulatory mechanisms of energy and matter turnover.
Partners: University of Trier
Funding: Deutsche Forschungsgemeinschaft - DFG
Project term: since 2019
New concepts for assessing soil structure turnover by structure labeling and analyses of biochemical gradients
Soil structure is the manifestation of the interactions of many biotic and abiotic agents in soil and controls many soil functions such as matter turnover, water retention, and the production of biomass. Soil structure has been identified to govern long-term carbon sequestration in soil via physical protection of soil organic matter against decay, therewith possessing a central role in the global carbon cycle. Soil structure is often considered static but actually changes due to bioturbation, wetting/drying, freezing/thawing and tillage activities. Yet, conceptual approaches to link soil structure turnover to organic matter decomposition are still in their infancy, mainly due to methodological shortcomings that impair meaningful estimates of soil structure turnover rates. The main objective of this project is to establish novel conceptual approaches to measure soil structure turnover under natural conditions. The first is based on structure labeling where soil aggregates are coated with small inert garnet particles and their fate is studied using X-ray microtomography (µCT). The speed at which randomization with respect to particle‒pore distances is achieved will be interpreted as turnover rate. The second is based on the detection of microscopic biochemical gradients. They are expected to form when soil structure turnover is slow, whereas fast soil structure turnover continuously changes diffusion pathways and redistributes constituents, thus preventing the formation of biogeochemical gradients. In this project we focus on imaging methods that provide a comprehensive in-situ view to undisturbed soil structure. Two-dimensional microscopic and microspectroscopic data (XPS, SEM-EDS, LA-IRMS) are merged with three-dimensional physical structure (µCT) through 2D-3D image registration in order to truly link 3D diffusion pathways to spatial gradients in element ratios, carbon oxidation states, and carbon isotope ratios. The proposed approaches will be tested in laboratory and field experiments to identify abiotic (wetting, freezing) and biotic (microbial activity, bioturbation) drivers of soil structure turnover. Long-term vegetation change experiments with known carbon turnover rates are revisited to estimate soil structure turnover from the magnitude of biochemical gradients. With this project we expect novel insights into the mechanisms of soil structure formation under natural conditions and how altered pore size domains and biochemical gradients are linked to the cycling of soil organic matter.
Partner: University of Bayreuth, Martin-Luther-University Halle-Wittenberg
Funding: Deutsche Forschungsgemeinschaft - DFG
Project term: 2018 - 2024
Rhizosphere Spatiotemporal Organisation – a Key to Rhizosphere Functions (SPP 2089)
This Priority Programme aims at the identification of spatiotemporal patterns in the rhizosphere and at the explanation of the underlying mechanisms. The key concept of the programme consists of approaching the rhizosphere as a self-organised system. Self-organisation arises from a cascade of feedback loops between root, microbiome and soil. Emerging patterns in the rhizosphere cannot be understood from studying the components in isolation. This call invites proposals from appropriate disciplines such as rhizosphere research, soil chemistry, plant genomics and physiology, soil microbiology, soil physics, exudate analysis, image/pattern analysis and modelling.
Application of 15N and 13C in the central experimental platform to investigate spatial gradients in the rhizosphere in respect to uptake and release
, Prof. Dr. Johanna Pausch
Partner: University of Bayreuth
Relevance of root growth and related soil structure formation for spatiotemporal patterns of chemical and biological properties and emergent system functions
Funding: EU - Horizon Europe Framework Programme (HORIZON)
Project term: 2022 - 2027
Root phenotyping and genetic improvement for rotational crops resilient to environmental change
As agricultural systems deteriorate due to climate change, European crop yield is projected to decrease by 30% by 2050. But even in the worst-case scenarios, some genotypes are resilient to stress because they inherited certain genes and traits. Searching for genetic markers associated with root traits able to contribute to this resilience is the goal of Root2Res, a European Union-funded research project assembling 22 partners based in Europe and Africa.
Root2Res is short for ‘Root phenotyping and genetic improvement for rotational crops resilient to environmental change'. It is a project that will go beyond the state of the art, developing new tools to evaluate root traits linked to sustainable crops, and measuring heritability and plasticity, that is, the ability to cope with environmental stress while delivering stable production. Working alongside breeders and farmers from areas under the greatest climatic stress, an interdisciplinary team is set to test cereals, tubers and legumes common and novel to European rotational systems.
Funded through Horizon Europe, the key EU research and innovation programme, Root2Res has received the green light amidst growing concern for food security. Focusing on drought and excess water as primary climate change hazards, the thirteen-nation project aims to provide diversified and resilient crops, securing healthy and nutritious food while enhancing nutrient use efficiency, carbon sequestration and reducing greenhouse gas emissions.
Cultivars developed by Root2Res could lead to global impacts: notably resilient yields that make rural economies viable, with higher quality of life for the farmers; resource-efficient crops with minimal impacts on changing environments; and, ultimately, feasible carbon-neutral societies.
UFZ Project within Root2Res: WP 5 " In-depth traits assessment and understanding of plasticity"
Partners: Coordinated by ARVALIS-Institut du végétal and scientifically led by ARVALIS and the James Hutton Institute, teams from RSK ADAS, KWS-L, ICARDA, CNR, FIBL, IRTA, BOKU, FJZ, UFZ, FEUGA, NEYKER, SOLYNTA, WU, UPM, KIS, UVIGO, ARC, TEAGASC, AU and UNIVDUN
Funding: Bundesministerium für Bildung und Forschung - BMBF
A joint project of the BMBF research initiative: BonaRes - Soil as a sustainable resource
ORDIAmur - Overcoming Replant Disease by an Integrated Approach
The apple replant disease has been known for a long time, but is a phenomenon that is not scientifically understood: with replanting, the soil loses its ability to serve as a substrate for plants of the same species and to provide consistently high yields. If the diseased soil is not disinfected, the replant disease persists for 20 to 30 years. The disinfection methods are based on thermal and chemical processes, which are costly and ecologically controversial or no longer permitted.
Based on the knowledge gained in ORDIAmur about the development of the replant disease, urgently needed management measures for the restoration of soil health shall be developed.
In the first project funding phase a biotest for the detection of apple replant was developed. Further results are to be mentioned: The replant disease is immobile and local. The composition of the soil microflora and soil microfauna changes structurally and functionally in replant soil. Early indicators of apple replant disease were identified at plant level, e.g. root development.
UFZ Project within ORDIAmur: W1 5 "Induction and etiology of regrowth disease in apple"
Partners: Gottfried Wilhelm Leibniz Universität Hannover, Helmholtz-Zentrum München GmbH, Helmholtz-Zentrum für Umweltforschung, Julius Kühn-Institut, Landwirtschaftskammer Schleswig-Holstein, Technische Universität Braunschweig, Universität Bayreuth