Grain, leafy, and tuber crops are fundamental to global food security and a balanced diet. However, climate change and rising levels of soil contaminants, such as metals, pose significant threats to future crop production. While the individual effects of these factors on yield quantity and quality are well-documented, their combined impact remains largely unknown. This project aims to assess the risks that climate change and metal pollution present to crop production and identify the most effective agricultural practices to mitigate potential losses. To achieve this, we utilize UFZ’s long-term field experiments—the (Global Change Experimental Facility and Static Fertilization Experiment) at Bad Lauchstädt Research Station, where crops are cultivated under varying climatic conditions, soil contamination levels, and farming practices. By analyzing crop yield quantity and quality, we investigate metal and nutrient accumulation in plants. To uncover the underlying mechanisms affecting crop yield, we collect rhizosphere samples throughout the growing season and conduct detailed geochemical (soil properties, metal bioavailability, metal binding sites) and microbiological (abundance, diversity, taxonomy, functionality) analyses. Additionally, we employ cutting-edge techniques such as zymography, planar optodes, and NanoSIMS to visualize the spatial distribution of metals and nutrients in and around plant roots.

By integrating these approaches, this research will provide critical insights into how climate change and metal contamination interact, ultimately guiding the development of sustainable agricultural strategies that support long-term food security. We explore phytoremediation strategies alongside crop production by integrating undersown crops. Compared to monoculture fields, undersown crops enhance soil health through various mechanisms. As part of the PhD college SmartManure, we investigate their potential to remove contaminants from liquid manure applied in corn production. Five different undersown crops are tested and compared for their ability to: 1) Extract and immobilize metals, 2) manage excessive nitrate, 3) extract and degrade antibiotics, and 4) reduce the proliferation of antibiotic resistance genes.

People involved:
Aleksandra Pienkowska, Jill Bachelder, Yunhong Zhang, Aria Duncan, Lena Mellin, Sunflower cover crop postdoc
 

This project is part of the Young Investigator Grant RhizoThreats: Rhizospheres under Attack from Coupled Climate and Soil Contaminant Stress, which is funded by the Helmholtz Association and the Centre for Environmental Research.

Phytoremediation is a powerful environmental remediation strategy that leverages the natural ability of plants to accumulate contaminants, such as metals, thereby reducing soil pollution. Our research focuses on understanding how environmental factors influence phytoremediation efficiency by studying the metal-hyperaccumulating model plant Arabidopsis halleri alongside various cover crops. To achieve this, we conduct greenhouse experiments under diverse conditions, including different soil types, metal contamination levels, climatic scenarios, and plant ecotypes. We examine how plant root systems interact with soil microbial communities and geochemical processes, shedding light on key factors that drive metal uptake and detoxification. By integrating physiological plant responses (root architecture, metal accumulation, enzymatic activity, chlorophyll content, stress markers), advanced microbial community assessments (amplicon sequencing, qPCR), and critical soil geochemical analyses (metal bioavailability, nutrient cycling, enzyme activities), we aim to uncover the mechanisms governing phytoremediator rhizospheres under both current and future climatic conditions. A deeper understanding of these processes is essential for optimizing phytoremediation strategies, with potential applications in agriculture. We recently published a paper discussing these concepts in the context of agricultural systems, contributing to the advancement of sustainable soil management practices.

People involved
Dr. Carolina Vergara Cid
Natalia Sánchez
Yunhong Zhang
Jessica Hamm
Lena Mellin
Sunflower cover crop postdoc

This project is part of the:
1. Young Investigator Grant RhizoThreats: Rhizospheres under Attack from Coupled Climate and Soil Contaminant Stress, which is funded by the Helmholtz Association and the Centre for Environmental Research.
2. NUTCLIME (Marie Skłodowska-Curie Actions by the European Commission).

Northern permafrost regions experience stronger warming than other regions in the world, thus are very sensitive to environmental change. A direct consequence is the thawing of permafrost in soils which is known to unlock huge amounts of C and N to biogeochemical cycling. Thawing results in a simultaneous ecosystem and plant-community shift from elevated, dry and nutrient-poor patches (palsa) inhabited by shrubs and mosses to inundated, wet and nutrient-rich areas (fen) dominated by mosses and sedges.

Plant type and cover are important controls to greenhouse gas balances in soils and may be decisive on whether soils are a sink or a source of gases to the atmosphere. So far, the role of root-mediated greenhouse gas producing versus consuming, transporting, releasing versus retaining processes is largely unknown. Root contributions to greenhouse gas emissions may range from root architecture to root microbiome and rhizosphere biogeochemistry impacts. This project evaluates a full thawing succession at the Abisco Scientific Research Station in Northern Sweden. Field installations, complex freeze-thaw incubation experiments followed by comprehensive analyses of rhizosphere biogeochemistry as well as microbiome signatures in combination with greenhouse gas flux measurements will be used to obtain a better understanding of root-soil interactions and the implications to greenhouse gas emissions from permafrost-affected soils. Specifically, we want to unravel the following research questions:

1. What role do root architectural variations play for both the transport versus entrapment of greenhouse gases and the presence, activity, and localization of greenhouse gas – producing versus consuming microbial communities?
2. What role do different root exudates and plant detritus play in microbially mediated greenhouse gas emissions?

This project is funded by the German Research Foundation (DFG) and is located at the University of Tübingen.
 

Blue-Green-Infrastructures (BGIs) are considered as promising approaches for reducing negative impacts of climate change in cities. The goal of BGIs is to restore the hydrological function of urban landscapes and manage stormwater to improve water quality and to manage water quantity. One example are tree trenches, which have an underground infiltration structure aiming to manage urban runoff after stormwater events. Trees growing in trench systems are exposed to a variety of organic pollutants that are deposited on surfaces and get washed away and transported in urban runoff. The release of these pollutants to the water cycle needs to be prevented. In a tree trench, pollutants can be taken up by the plant, and transformed to less toxic substances by the interplay of microorganisms and plants. As knowledge about the mechanistic and potential of plant-microbe interactions in tree trenches is missing, we aim to elucidate the capacity and mechanistic functioning of plant-microbe interplay in tree trenches to degrade typical organic pollutants of urban runoff as well as to stimulate microbial communities and their potential pollutant (co-)metabolisms by organic priming. The combination of analyzing the contaminant concentration, isotopic composition and bacterial and fungal community will provide an improved understanding of ecosystem services mediated by plant-microbe interactions in tree trenches and the potential of tree trenches to clean urban runoff water.

This project is part of the CLEANER PhD college.

People involved:
Karolin Seiferth, Noah Furth

Main collaborators: Steffen Kümmel, Carsten Vogt, Dietmar Schlosser, Xinzhu Yao

Courses are offered through the Geoscience Department of the University of Tuebingen.

• Winter Semester 2024/25: Biologie für Umweltnaturwissenschaften (introductory level Bachelor degree course): Module Flechten als Bioindikatoren und Holzabbau (co-teaching with Prof. Dr. Michaela Dippold, Dr. Kyle Mason-Jones, Dr. Svenja Stock, Dr. Ilonka Engelhardt) 
• 10-21.03.2025: Block course (lecture, seminar and lab course) at Master degree level Rhizosphere Processes in a Changing World (6 ECTS) 
• Summer Semester 2025: Geosphere-Biosphere interactions (Mandatory Master degree level course, co-teaching with Prof. Dr. Michaela Dippold)
  

Bachelor Theses:

• Lena Haas: Impact of root oxygenation versus root exudation on greenhouse gas release in a thawed permafrost soil. 2024
• Charlotte Roschke: Acclimating Italian paddy soil to heavy metals and to different climatic conditions for use in experiments. 2022
• Jenin Fleischmann: Soil microbiome adaptation to metal stress under different farming practices. 2022
  
• Julia Kost: DNA/RNA Stability in Environmental Samples. 2021
• Alexandra Glöckle: Effect of cadmium on (a)biotic greenhouse gas emissions in agricultural soil. 2020
• Katja Lenge: Long term effect of cadmium contamination and climatic stress on soil microorganisms and greenhouse gas emissions. 2020
• Sebastian Müller: Cadmium stress combined with elevated temperature will increase greenhouse gas emissions more than elevated carbon dioxide combined with or without cadmium. 2020

Master Theses:

• Shital Khadela: Understanding Rhizobiome dynamics of Spinach under climate-induced heavy metal (Cadmium-Cd) stress in organically and non-organically managed soils. 2024
• Natasha Kalantar: Comparative biogeochemical analysis of Arabidopsis halleri and A. lyrata in heavy metal contaminated soils: Insights into adaptation mechanisms. 2024
• Katja Lenge: Influence of plant-specific root traits on the release of greenhouse gases from thawing permafrost soils. 2024
  
• Paula Kosel: Biogeochemical adaptation of paddy soil to climate change. 2022
• Mara Breit: What determines intraspecific variability in heavy metal hyper-accumulation efficacy of Arabidopsis halleri? – Plant traits or soil biogeochemistry? 2022
  
• Esmira Bibaj: Cadmium (Cd) and climate-impacted greenhouse gas emissions from agricultural soils. 2022
  
• Viktoria Skudlik: Combined impact of elevated atmospheric CO₂ and soil Cd on the nitrogen cycle in agricultural soils. 2022