Abgeschlossene Forschungsprojekte
Messung und Modellierung von Bodenfunktionen
Funding: Deutsche Forschungsgemeinschaft - DFG
Project term: 2019 - 2023
Monitoring and modelling of non-equilibrium soil water dynamics and lateral subsurface flow in hillslope soils
In well-drained, unsaturated soils, water moves predominantly vertically. Lateral flow is initiated at locations where the soil approaches water saturation and capillary forces vanish. The onset of lateral flow along impeding soil horizon boundaries and other heterogeneities in hillslopes cannot be described realistically even with spatially-distributed 3D numerical models. A process-based model concept for transient lateral flow in the unsaturated zone of hillslope soils is still missing. One major difficulty to develop such a concept is that water dynamics in field soil exhibit non-equilibrium effects and hysteresis due to structural heterogeneities. Consequently, lateral flow is triggered already at local water potentials close to zero, i.e. far before complete water saturation occurs as is commonly assumed. Another difficulty is the need for a 2D or 3D representation of the hillslope and the corresponding high demand of both data and computing power.In this project, we develop a conceptual framework to described non-equilibrium dynamics and hysteresis for 1D vertical flow in a physically consistent way. The analysis will be based on unique data sets provided by the VAMOS lysimeter system and the TERENO-SoilCan lysimeter network, which monitor water contents and matric potentials in different field soils (3D) and lysimeters (1D) since 2013.
Contact:
Prof. Dr. Hans-Jörg Vogel
, Dr. Horst Herbert Gerke, Dr. Thomas Wöhling
Partner:
Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V., Dresden University of Technology - TU Dresden
Funding: Bundesministerium für Bildung und Forschung - BMBF
Project term: since 2018
Innovative solutions for a sustainable agricultural land use in the dry steppes of Kazakhstan and southwestern Siberia
In the arid steppe regions of Kazakhstan and southwestern Siberia, the problems of soil degradation, climate change, and change of land use necessitates innovations for a sustainable use of agricultural resources. By a distinguished combination of research, development, and implementation, the project aims at developing innovative, sustainable, and climate-adapted agricultural concepts and to support infrastructure for an information and advisory system, based on an already perfectly established cooperation between scientists, German companies as well as local land users and other interest representatives.
SP 2 - Optimization of water supply by innovative soil management
Plant-accessible water is the limiting factor for agricultural yields in the steppe zone of Kazakhstan, especially in the light of the ongoing climate change with an increase in the mean annual temperatures along with more infrequent precipitation events in the study area. SP 2 aims at improving soil water supply to plants, e.g. by optimization of snow retention or by reducing unproductive evaporative water losses by ultra-shallow soil tillage practices. For that a novel weighable lysimeter station consisting of two gravitation lysimeters and allowing long-term online operation will be developed and implemented, and quantitative and qualitative parameters of the soil water budget will be recorded for different soil management systems. High-resolution measurements concern for example the determination of the actual evaporation. Being equipped with a multitude of atmosphere and soil, the lysimeter station of SP 2 will also serve as a basis for the recording climate change effects in the region of the Kazakh dry steppes and compared with the development in the Kulunda steppe in southwest Siberia, where another lysimeter station is running. With additional information from the analysis of plant water and nutrients uptake, efficient water management approaches for sustainable and resource saving agriculture will be developed.
Contact:
Partner: UGT
Web: http://rekks.eu/en
Funding: Deutsche Forschungsgemeinschaft - DFG
Project term: 2016 - 2023
Denitrification in Agricultural Soils: Integrated control and Modelling at various scales
Denitrification, the process of nitrate reduction allowing microbes to
sustain respiration under anaerobic conditions, is the key process
returning reactive nitrogen as N2 to the atmosphere. The different
reaction steps (NO3- -> NO2- -> NO -> N2O -> N2) are enzymatically
mediated by a broad range of prokaryotes and some eukaryotes. Actively
denitrifying communities in soil show distinct regulatory phenotypes
(DRP) with characteristic controls on the single reaction steps and
end-products. It is unresolved whether DRPs are anchored in the
taxonomic composition of denitrifier communities and how environmental
conditions shape them. Despite being intensively studied for more than
100 years, denitrification rates and emissions of its gaseous products
can still not be satisfactorily predicted. While the impact of single
environmental parameters is well understood, the complexity of the
process itself with its intricate cellular regulation in response to
highly variable factors in the soil matrix prevents robust prediction
of gaseous emissions. Key parameters in soil are pO2, organic matter
content and quality, pH and the microbial community structure, which in
turn are affected by the soil structure, chemistry and soil-plant
interactions. Here, we aim at the quantitative prediction of
denitrification rates as a function of microscale soil structure,
organic matter quality, DRPs and atmospheric boundary conditions.
Combining state-of-the-art experimental and analytical tools (X-ray
µCT, 15N tracing, NanoSIMS, micro-sensors, advanced flux detection, NMR
spectroscopy, and molecular methods including next generation
sequencing of functional gene transcripts), we will study
denitrification processes at unprecedented spatial and temporal
resolution. Improved numerical methods and computational power will
allow to integrate results from the different groups and to develop
denitrification models ranging from the microscale (phase 1) to the
field/plot scale (phase 2).
Contact:
Dr. Steffen Schlüter , Prof. Dr. Hans-Jörg Vogel
Web: DASIM
Project term: 2019 - 2021
Project: Agricultural and aquatic systems
The aim of the “Agricultural and aquatic systems” project is to record the development of these sensitive and complex systems with regard to climatic extremes in Germany. We want to predict as closely as possible the development of soil functions, agricultural productivity, as well as the water quality of river ecosystems for different climate scenarios.
Contact:
Dr. Mareike Ließ
,
Prof. Dr. Hans-Jörg Vogel
,
Prof. Dr. Markus Weitere
, Prof. Dr. Claudia Künzer
Partner: DLR
Web: Hi-Cam