Internationale Grünland-Konferenz 2025

15 Jul 2025, 08:00 → 17 Jul 2025, 23:00 Europe/Berlin

Großer Seminarraum/ Large Seminar Room (Garmisch-Partenkirchen)

David Piatka (IMK-IFU - KIT), Michael Dannenmann (IMK-IFU - KIT), Ralf Kiese (IMK-IFU - KIT)

Grünlandökosysteme prägen die Alpen und das Alpenvorland Süddeutschlands auf über einer Million Hektar. Sie sind nicht nur eine wichtige Grundlage für die Milch- und Fleischwirtschaft, sondern übernehmen auch zentrale Ökosystemfunktionen. Sie speichern Kohlenstoff und Stickstoff, regulieren den Wasserhaushalt, schützen vor Erosion und sind wichtig für die biologische Vielfalt.

Jedoch stellen der Klimawandel, sowie veränderte Landnutzung und Bewirtschaftungsmethoden diese wertvollen Ökosysteme vor große Herausforderungen. Wie wirken sich diese Veränderungen auf die Funktionen des Grünlands aus? Welche nachhaltigen Strategien gibt es für die Zukunft? Und welche wissenschaftlichen Ansätze und Bewirtschaftungsmethoden können dazu beitragen, Grünlandökosysteme langfristig zu erhalten?

Das vom Bundesministerium für Bildung und Forschung (BMBF) geförderte Projekt SUSALPS lädt dazu Forscher, Behörden, Organisationen und Landwirte zur Internationalen Grünlandkonferenz 2025 in Garmisch-Partenkirchen ein. Tauschen Sie sich mit Experten aus, diskutieren Sie neueste Forschungsergebnisse und entwickeln Sie gemeinsam Lösungen für eine nachhaltige Grünlandbewirtschaftung.

Die Konferenz erstreckt sich über drei Tage und deckt sowohl wissenschaftliche als auch praktische Perspektiven ab.

Für die Teilnahme an der Konferenz fallen keine Gebühren an. Für Verpflegung (Kaffe/Kuchen & Mittagessen) wird gesorgt.

 

Grassland ecosystems characterize the Alps and the Alpine foothills of southern Germany on over one million hectares. They are not only an important basis for the dairy and meat industries, but also perform key ecosystem functions. They store carbon and nitrogen, regulate the water balance, protect against erosion and are important for biodiversity.

However, climate change, as well as changes in land use and farming methods, pose major challenges to these valuable ecosystems. How do these changes affect the functions of grassland? What sustainable strategies are there for the future? And which scientific approaches and management methods can help to preserve grassland ecosystems in the long term?

The SUSALPS project, funded by the Federal Ministry of Education and Research (BMBF), is inviting researchers, authorities, organizations and farmers to the International Grassland Conference 2025 in Garmisch-Partenkirchen. Exchange ideas with experts, discuss the latest research findings and jointly develop solutions for sustainable grassland management.

The conference spans three days and covers both scientific and practical perspectives.

There are no fees for participation in the conference. Catering (coffee/cake & lunch) will be provided.

Tuesday 15 July

08:00 Arrival & Registration

Welcoming

Convener: Ralf Kiese (IMK-IFU - KIT)

1 Welcoming

Speaker: Ralf Kiese (IMK-IFU - KIT)

Biogeochemical cycling in grassland soils

2 Keynote: Effects of different manure application techniques on the nitrogen balance of grassland

Speaker: Dr Michael Dannenmann (IMK-IFU - KIT)

3 Nitrogen cycling processes in soil organic matter pools of grasslands as mediated by land use intensity and soil diversity

Soil organic matter (SOM) provides crucial storage for carbon but also contains a majority of soil nitrogen. Land use intensity (LUI) may affect the particulate and mineral-associated SOM pools having repercussions on the carbon and nitrogen storage and cycling. Soil organic matter dynamics and composition plays a key role for the extent of these processes, yet its interactions remain poorly understood preventing targeted mitigation measures for carbon and nitrogen-related soil functions. Here we provide insights investigating how LUI and soil properties affect the storage of carbon and nitrogen in functional SOM pools in the topsoil (0-30 cm) of grassland soils across three different regions in Germany. Furthermore, we present a conceptual framework integrating biological, mineral, and organic nitrogen pools to disentangle nitrogen cycling processes and their interactions with organic matter dynamics.

Across the land use intensity gradient, we isolated particulate organic matter (POM), which is part of the >20 μm fraction, and mineral associated organic matter (MOM) in the <20 μm fraction. Random forest and mixed model analysis showed that LUI did not significantly affect SOM storage, but led to reduced C/N ratios in POM and MOM, driven by increased N fertilization intensity. Rather than land use intensity, soil properties, such as clay and iron oxide content, and soil type diversity exerted most influence on SOM.

To reconcile the influences of soil properties on soil nitrogen cycling, we provide a novel conceptual framework integrating organic matter stabilization mechanisms, microbial N uptake and release as necromass, as well important processes catalyzed by the soil microbiome including biological nitrogen fixation pathways. Our integrative nitrogen cycling framework stimulates different disciplines towards a new perception of the nitrogen cycle in unlocking multiple organic nitrogen pools as mediated by soil type and climatic conditions.

Speaker: Dr Steffen A. Schweizer (Technical University Munich, TUM School of Life Sciences, Research Department Life Science Systems, Chair of Soil Science)

4 Climate Change Impacts on Water Fluxes in Montane Grassland: Insights from Lysimeter Experiments and Catchment-Scale Modeling

Montane grasslands play a vital role in regional water cycling and agricultural productivity, yet their response to climate change remains insufficiently understood. This study presents findings from a multi-year climate manipulation experiment in the Austrian Alps, where high-precision lysimeters combined with warming (+3 °C) and elevated CO₂ concentrations (+300 ppm) were used to assess changes in evapotranspiration (ET), soil moisture, seepage, and biomass yield. A modeling framework based on HYDRUS-1D and Penman–Monteith formulations was applied to extrapolate results across scales. Elevated CO₂ consistently reduced ET and increased seepage due to partial stomatal closure, despite no significant change in leaf area index. In contrast, warming increased ET and reduced groundwater recharge, particularly during dry spells. When combined, the CO₂-induced water-saving effect only partially offset the warming-induced losses. Drought years (2018–2020) revealed strong yield reductions under ambient and warmed conditions, while elevated CO₂ mitigated these effects. Additional isotope tracing experiments using deuterium-labeled water showed altered post-drought soil water transport under combined warming and CO₂ enrichment, with reduced mixing and delayed infiltration. Upscaling using multiple hydrological models revealed differing sensitivities at plot and catchment scale, emphasizing the need for multi-model approaches in future impact assessments. Our results underline the importance of incorporating vegetation response to CO₂ in ecohydrological models and suggest that montane grasslands may provide limited resilience to climate-driven shifts in water availability.

Speaker: Dr Markus Herndl (HBLFA Raumberg-Gumpenstein Institut für Pflanzenbau und Kulturlandschaft Abteilung Umweltökologie)

5 “Moormilch”: Dairy farming on wet peatland soils - Options, Grassland Management and Valuation

Raising water levels in peatlands is an important component in reducing greenhouse gas emissions and therefore achieving the legally defined climate protection targets. However, high water levels on agricultural land require adapted management, which usually results in changing existing work and operating procedures.
Peat soils in Baden-Wuerttemberg are mainly located in the southeast of the state. Rather small dairy farms, partly using drained fens for intensive grassland management, characterize this region. Many management options for wet peatland, such as the cultivation of paludiculture for fiber usage, are hard to integrate into dairy farms. In addition, the agricultural land is crucial for fodder production. Practical concepts that are specially adapted to dairy farms are therefore essential to reach rewetting goals.
The aim of the “Moormilch” project is to develop practical, yet climate friendly and profitable solutions for agricultural use of fens, with a special focus on the Allgaeu and Upper Swabian region in Baden-Wuerttemberg. In particular, utilization options for cattle feeding will be developed and demonstrated for practitioners. Prior experiments have identified the cultivation of tall fescue (Festuca aundinacea) as a viable option on wet fens with an acceptable fodder value. Therefore, tall fescue will be cultivated on experimental and demonstration sites to gain experience in the cultivation and to transfer knowledge to practitioners. Beyond that, the climate relevance of these measures will be investigated and evaluated by means of greenhouse gas measurements on the experimental sites.
Additionally, a feeding trial with tall fescue as part of the feed ration in dairy cattle will be conducted to use as an in-house fibre source and evaluate pros and cons in animal performance. As part of the project, product valuation to compensate for the higher costs of such management will be investigated, with local dairy plants being a crucial stakeholder in this process.

Speaker: Dr Marcus Schlingmann (Agricultural Centre for cattle production, grassland management, dairy food, wildlife and fisheries Baden-Wuerttemberg)

10:25 Coffee Break

Plant & Microbial Biodiversity

6 Keynote: The soil microbiome – Mitigator or origin of climate change ?

The soil microbiome plays a pivotal role in biogeochemical cycles, particularly in carbon and nitrogen cycling, which are central to the regulation of Earth's climate. As global climate change accelerates, understanding whether the soil microbiome functions primarily as a mitigator or as a contributor to this threat is increasingly critical.
Recent advances in metagenomics, isotope tracing, and environmental modeling have revealed that soil microbial communities significantly influence carbon fluxes between terrestrial ecosystems and the atmosphere. Microbial processes such as SOM decomposition, nitrification, denitrification, and methanogenesis govern the turnover of key greenhouse gases, including carbon dioxide (CO₂), nitrous oxide (N₂O), and methane (CH₄). In stable ecosystems, especially unmanaged forests and undisturbed grasslands, microbes facilitate carbon sequestration by stabilizing organic matter in soils and promoting plant-microbe symbioses that enhance biomass productivity and drought resilience. These functions position the soil microbiome as a potential climate change mitigator.
However, microbial contributions to climate change are highly context dependent. Disturbances such as intensive agriculture, deforestation, and permafrost thawing alter microbial community structure and function, often leading to elevated greenhouse gas emissions turning the soil microbiome into a potential accelerator of climate change.
Thus, the answer to the question - whether the soil microbiome is a mitigator or origin of climate change?— is not binary. The soil microbiome is both, and its trajectory is ultimately shaped by human stewardship as well as environmental conditions including climate change itself.
The key question is: How can microbial processes be managed or engineered to enhance their climate-mitigating capabilities? Promising strategies include promoting beneficial microbial taxa through conservation agriculture, rewilding degraded lands, applying biochar, and developing microbial inoculants designed to stabilize soil carbon. However, the high complexity and variability of microbial communities on the one hand and differences in site specific properties like soil type, management or climate on the other hand exacerbate prediction and control. Thus the “One fits all solution” might be never achieved. Furthermore, current Earth system models inadequately represent microbial processes, underscoring the need for more integrative research at the intersection of microbiology, soil science, and modeling.
The presentation will give an overview about current state of the art describing the dual role of the soil microbiome that can either buffer or exacerbate climate change mainly focussing on grassland ecosystems. The presentation will also address the question of the stoichiometry of nutrients and if subsequent adaptations in management might be a possibility to induce targeted changes in the soil microbiome composition and activity pattern, which could also influence greenhouse gas emission pattern .

Speaker: Prof. Michael Schloter (Helmholtz Zentrum München)

7 Impact of organic fertilization on microbiomes along the trophic chain in grassland ecosystems

Background: Agricultural grasslands are often managed intensively, influencing soil properties and local macro and micro- communities. The impacts of such anthropogenic changes are not limited to host diversity but can also affect diversity of host-associated microbial assemblages. These changes can have cascading effects across ecosystems, resulting in significant community alterations and challenges to health and function at different levels along the trophic chain.

Methods: This study investigates how fertilization affects microbial communities in grassland ecosystems in multiple connected trophic compartments treated with organic fertilizers, i.e. biogas digestate, cow/horse manure, and pig slurry, using high throughput 16S rRNA gene sequencing.

Results: Our results indicated shifts in microbial composition in response to fertilization, which were most pronounced in belowground trophic compartments. These changes were strongly host-dependent, with the pig slurry treatment exerting the greatest impact. The presence of overlapping bacterial genera across soil, plant, and animal compartments suggests strong interactions between trophic levels. Although pig slurry-derived microbes were detected in all compartments, their low prevalence indicates an indirect effect of fertilization, associated with changes in nutrient availability.

Conclusions: Our findings demonstrate that belowground and aboveground trophic levels respond differently to fertilization-induced microbial alterations. This highlights the importance of considering host-specific and trophic interactions when evaluating the impacts of anthropogenic disturbances on ecosystems and their implications for environmental and human health.

Speaker: Karoline Jetter (Universität Ulm)

8 Grazing for science - experiment on a species rich abandoned mountain pasture in the Oberammergauer alps and its impacts on biodiversity

Over centuries mountain pasture has been a traditional way of agriculture in the alpine regions in Europe. This seasonal grazing led to species- and nutrient rich alpine grassland combined with human maintenance even below the tree line. Due to societal change and economic pressure within the last 50 years lots of those mountain pastures had been abandoned. So, the study area Brunnenkopfalm in the Oberammergauer Alps, Germany (1400-1700mm NN). Since early summer 2018 the around five ha pasture has been restocked yearly with five to seven Murnau-Werdenfelser cattle, which is a small frame local breed. After an initial monitoring before the regrazing we measured the floristic biodiversity and biomass. To determine the impact of the cattle on those parameters, five fenced control plots were installed on the pasture next to five unfenced plots where the cattle could graze on. The measurements were repeated each experimental year until 2025.
This study showed, that grazing increased the floristic evenness and decreased the plant cover and biomass on site. However, the measured regrowth effect indicates that grazing causes an overall increase in over the year grown biomass. This leads to the conclusion, that floristic biodiversity on alpine pastures benefits directly from grazing and therefore should be used as a tool for preserving valuable alpine grassland.

Speaker: Jonathan Ehrmann (Department of Disturbance Ecology and Vegetation Dynamics, University of Bayreuth, Germany)

9 Grassland bud and shoot demographic responses to single and recurrent droughts vary across an aridity gradient

Clonal demographic traits play important roles in regulating community dynamics. Yet, it remains unclear how the responses of these clonal traits to drought might depend on previous drought exposure, and how drought responses vary among grasslands. We conducted a repeated drought experiment across four grasslands along an aridity gradient in the Mongolian plateau. We assessed the effects of single (precipitation reduction in 2021-2022) vs. recurrent (precipitation reduction in 2015-2018 and 2021-2022) drought on bud density, shoot density, and the ratio of bud to shoot density. Drought reduced bud density at all grasslands and shoot density at most grasslands. Drought reduced the ratio of bud-to-shoot density only in the most arid grasslands. Recurrent drought had larger negative effects than a single drought on bud density and composition of bud and shoot at only one of four grasslands, and on shoot density at two of four grasslands. Our results suggest that previous drought exposure can alter the response of plant clonal demographic traits to subsequent drought in some but not all grasslands and that responses can vary with mean climate.
Keywords: bud limitation, climate change, drought frequency, population regeneration, Mongolian plateau

Speaker: Teniwu Teniwu (University of Bayreuth)

12:10 Lunch Break

Vegetarian (optional vegan) lunch

Remote Sensing & Modelling

10 Keynote: Grassland ecosystem services in a changing climate – combining advisory guidelines and process-based modelling to support adaptation

The National Climate for Climate Services (NCCS) is currently implementing a programme aimed at developing decision-making tools for dealing with climate change in Switzerland. As a contribution to “Ecosystem Services”, one of the projects included in the programme, Agroscope is setting up an interactive information platform that will allow users to display the projected impacts of climate change on grassland ecosystem services. Given the practical scope, it is important that the data displayed on the platform match the information already available for advising stakeholders. For instance, the current fertilisation recommendations in the official guidelines published by Agroscope target yield levels that reflect the empirical knowledge obtained from field trials and monitoring programmes. To ensure consistency with this information, a mixed approach was therefore selected to develop the new platform, in which empirical relations between elevation, climate and management deliver the basis for creating maps of current productivity levels, while simulations with a process-based model driven with climate change scenarios are conducted to chart the impacts of elevated CO2 concentrations, rising temperatures and shifts in precipitation patterns on grassland productivity. This presentation will illustrate the steps involved in the development of the platform and provide initial impressions of the final product.

Speaker: Dr Pierluigi Calanca (Agroscope)

11 SatGrass: Satellite based estimation of grassland yield and quality dynamics

Grassland represents the most important land-use system in European alpine regions. Various utili-sation intensities caused by different site conditions, small-scaled structures and multiple cuts per growing season impede a systematic estimation of yield and forage quality. During the growth of grassland, the biomass increases, while at the same time, the forage quality decreases with continu-ing plant development. Objective estimates of these two parameters in near-real time are difficult to make, even for experienced observers, but would be essential for optimizing grassland manage-ment. In addition, continuous yield and quality monitoring on a regional scale would be an instru-ment for statistical analysis, agricultural policy and advisory services and a basis for risk manage-ment. The impact of climate change, particularly the increasing risk of drought, requires objective and regional-based yield assessments for efficient climate adaptation and mitigation.
In the SatGrass project, we combine remote sensing, weather and grassland data to calibrate and validate yield and quality estimation models based on 211 meadows throughout Austria. On these fields, yields were measured every two weeks during the growing seasons 2021 to 2023 for three randomly selected square meters each (12,063 samples). We also assessed the plant composition and the leaf area index (15,610 AccuPAR measurements). The three replicated fresh matter sam-ples were mixed to 4021 samples and analyzed for dry matter yield and forage quality (crude pro-tein content). The models need to consider the start of the growing season (SOS). Therefore, we established a new methodology for identifying the SOS by combining remote sensing (MODIS NDVI at 250m) and temperature thresholds from daily weather data. The end of each growth is determined by the cut. With 1400 observations of cut dates, we developed two cut models, one based on Sentinel-2 and the other on a combination of Sentinel-2 and Sentinel-1 using a fitted NDVI curve obtained by iteratively smoothing the upper envelope of the actual observations using the Whittaker smoother. Cuts are detected by meeting a threshold in the difference between the fit-ted NDVI curve and the actual observed NDVI values. The yield and quality models are based on machine learning algorithms with a sequential multilayer model implemented in R (Keras for Ten-sorFlow). The input layer for the biomass estimation includes aggregated weather data and Senti-nel-2 based vegetation indices.
The SatGrass scientific approach, which involved collecting extensive ground-truth data and mod-elling SOS, cut dates, grassland yield and forage quality based on this unique database, has been completed successfully. Because of the high quality and robustness of the results, an operational system is now being implemented as a mobile and a dashboard application with the support of the European Space Agency and the Austrian Federal Ministry of Agriculture and Forestry, Regions and Water Management to make the results available to farmers and agricultural organizations as a management and monitoring tool of real-time information of grassland yield and forage quality.

Speaker: Dr Andreas Schaumberger (Agricultural Research and Education Center (AREC) Raumberg-Gumpenstein)

12 Satellite remote sensing for extensive analyses of grassland ecosystem functions in southern Germany

Grasslands are widespread ecosystems that play a vital role in providing multiple ecosystem functions, particularly as sources of fodder. Despite their ecological and economic importance, knowledge about grasslands remains limited due to their high heterogeneity in use and management and, consequently, their species composition. This is particularly the case in regions such as southern Germany, where a wide variety of grassland types exists. Remote sensing offers significant potential for large-scale, consistent, and continuous monitoring of grassland characteristics. Within the SUSALPS project, various aspects of grassland ecosystems were investigated using Sentinel-2 (S2) satellite data. This research focused on analyzing mowing dynamics, yield, nitrogen content, and flower species richness of grasslands across multiple years. Mowing events were detected for the years 2018-2024 for entire Germany using high-resolution S2 time series and a rule-based thresholding method, achieving an average accuracy (F1-Score) of 0.65. Grassland biomass was estimated with S2 time series and in-situ measurements from 2019 to 2022 using an extreme gradient boosting algorithm, yielding an R² of 0.69. Grassland yield estimation was based on the estimated multi-temporal biomass and the mowing dates and conducted for the Ammer catchement area in southern Germany. Nitrogen content and species richness were estimated with a random forest approach also based on S2 time series, demonstrating promising results (R² = 0.79 and 0.56, respectively) for the SUSALPS study regions in the Ammer catchment area in southern Bavaria and the Rotmain-Weißmain catchment area in northern Bavaria. The resulting remote sensing-based products provide valuable insights into grassland dynamics and support both scientific modelling and decision-making processes for sustainable land management.

Speaker: Dr Sophie Reinermann (DLR DFD-LAX)

13 Retrieval of grassland traits from optical satellite data – the challenge of developing transferable models

Spatially explicit information on grassland traits (e.g., biomass, plant N content) can support the optimization of grassland management. Previous studies demonstrated the potential of remote sensing to retrieve different plant traits in grasslands using multispectral and hyperspectral sensors. However, most of these studies used empirical approaches and are therefore hardly transferable to other regions. Hybrid retrieval approaches, combining physically-based models with machine learning (ML), aim for a better model generalization and transferability. These hybrid approaches were mainly developed for hyperspectral data and crops such as wheat and maize. In this study, we developed and tested hybrid retrieval models for different grasslands traits like aboveground biomass (AGB) and canopy N content based on the radiative transfer model (RTM) PROSAIL-PRO and Gaussian progress regression (GPR) using hyperspectral EnMAP data. Three datasets of in-situ and partially corresponding satellite data of differently managed grasslands from Poland, Germany, and Italy, were available for model calibration and validation. Finally, the trained retrieval models were applied to available EnMAP scenes of the test regions to map the selected grassland traits. Despite promising results in the model testing, the validation results of the retrieval models were not satisfying. In our contribution we will present details of our approach and the results as well as the challenges in developing transferable retrieval models for grasslands.

Speaker: Dr Anne Schucknecht (OHB System AG)

14:25 Coffee Break

Socioeconomy

14 Keynote: Mountain grasslands under pressure: Impacts of land use and climate changes on ecosystem services

Mountain grasslands have been shaped by human activities over centuries, contributing to the provision of crucial ecosystem services to people living inside and outside mountain regions. However, mountain grasslands in the European Alps nowadays are facing significant transformations, mainly due to changes in the grassland management as well as climatic variations. Spatially explicit and quantitative analyses indicate that the abandonment or reduction of grazing and mowing activities generally results in lower levels of provisioning and cultural services at higher elevations. At lower elevations, the increased management intensity has focused on higher forage production, but the grassland area has been reduced due to urban sprawl or the conversion to annual or permanent cultures. Under future socio-economic scenarios, land-use changes tend to be less significant, while reforestation processes will continue to alter ecosystem services of former grassland areas in the long-term, amplifying the shift from typical grassland ecosystem services towards forest-related ecosystem services. In addition, the importance of climate change in driving changes in grassland ecosystems will increase, affecting particularly provisioning and cultural services and reducing management options. These findings emphasize the need for an adapted and more flexible management as well as for developing shared visions of appropriate and sustainable future pathways to maintain and enhance desired ecosystem services.

Speaker: Dr Uta Schirpke (Institute for Alpine Environment, Eurac Research)

15 New insights into carbon footprints of dairy farming in pre-alpine regions of Germany: The role of emissions from drained peatlands in milk production

Greenhouse gas (GHG) emissions from agriculture significantly contribute to climate change, with drained peatlands representing a substantial and often overlooked source, especially in Germany where 95% are drained for agriculture. Existing life cycle assessments (LCAs) of milk production often underestimate environmental impacts by neglecting these soil emissions. This study quantified the influence of peatland-derived emissions on the carbon footprint (CF) of milk production from three dairy farms located on drained peatlands in pre-alpine Bavaria, Germany.
We calculated CFs with and without peatland emissions, applying three methodological approaches: IPCC Tier 1, Tiemeyer et al. (2020) implied emission factors (EFs), and Tiemeyer et al. (2020) water table-dependent (WTD) response functions. A calculated near-natural peatland reference scenario was also established to contextualize these emissions. Our findings show that peatland emissions are a highly significant contributor, increasing milk CFs by over double on average, and becoming the dominant emission source. The chosen methodology notably influenced calculated CFs, with WTD-dependent approaches yielding higher estimates. Although subtracting baseline emissions from a near-natural scenario resulted in a minimal CF reduction (3.95% to 8.29%), the substantial impact of drained peatlands remained robust.
This study underscores the crucial importance of explicitly including peatland emissions in dairy LCAs for accurate environmental assessment. Results highlight the urgent need for targeted mitigation strategies, particularly water table management, to reduce the climate impact of agriculture on drained peatlands.

Speaker: Anna-Lena Muller (IMK-IFU - KIT)

16 An agent-based model to simulate field-specific nitrogen fertilizer applications in grasslands

Fertilization plays an important role in grassland management and decisions are usually made at farm level. Data on fertilizer application rates are crucial for an accurate assessment of the effects of grassland management on ecosystem services. However, these are generally not available on farm/field scale. To close this gap, we present an agent-based model for Fertilization In Grasslands (FertIG). Based on animal, landuse, and cutting data, the model estimates grassland yields and calculates field-specific amounts of applied organic and mineral nitrogen on grassland (and partly cropland). Furthermore, the model considers different legal requirements (including fertilization ordinances) and nutrient trade among farms. FertIG was applied to a grassland-dominated region in Bavaria, Germany comparing the effects of changes in the fertilization ordinance as well as nutrient trade. The results show that the consideration of nutrient trade improves organic fertilizer distribution and leads to slightly lower mineral N applications. On a regional scale, recent legal changes (fertilization ordinance) had limited impacts. Limiting the maximum applicable amount of organic N to 170 kg N/ha fertilized area instead of farm area as of 2020 hardly changed fertilizer application rates. No longer considering application losses in the calculation of fertilizer requirements had the strongest effects, leading to lower supplementary mineral N applications. The model can be applied to other regions in Germany and, with respective adjustments, in Europe. Generally, it allows comparing the effects of policy changes on fertilization management at regional, farm and field scale.

Speaker: Dr Andrea Kaim (Helmholtz-Zentrum für Umweltforschung - UFZ)

17 Biomass production of Grasslands: Spatial distribution of biomass production and feed demand in two contrasting regions of Bavaria, Germany

For agriculture, biomass production for feeding livestock is an essential ecosystem service of grasslands. In line with the European Green Deal’s farm-to-fork strategy, maximizing fodder production from existing grasslands is more sustainable than relying on high-intensive cropland feed. Reducing imports and dependency on cropland feed is a global environmental goal. However, it remains unclear whether current grassland resources can sufficiently meet livestock’s energy needs. This study assesses the balance of metabolizable energy (ME) from grasslands in two contrasting regions of Bavaria, Germany. We estimate the ME balance per farm and year using data from the Integrated Administration Control System (IACS), including field usage, livestock information, and modeled yield data. We analyze variations between a dry year (2018) and a typical year (2020) under conventional and organic farming. Results show an average ME deficit of ~1,000 GJ per farm (equivalent to 17 dairy cows) in northern Bavaria, whereas the (pre-)Alpine region in southern Bavaria generally shows surpluses, roughly one potential additional dairy cow per farm (~60 GJ surplus). Within the southern region, a north-south trend appears, with deficits in the north and surpluses in the south. No clear pattern emerges in northern Bavaria. Organic farms tend to exhibit higher ME surpluses than conventional farms. A geographically weighted regression reveals that elevation, precipitation, agri-environmental schemes, and farming practices significantly influence ME balances, with effects varying spatially. These findings underscore the need of region-specific strategies to optimize grassland fodder production and enhance the resilience of livestock farming in a changing climate.

Speaker: Sylvia Helena Annuth

16:10 Coffee Break

Poster Session & Get-Together (including Beer & Pretzels)

18 A model-based decision support system for sustainable grassland management

The Decision Support System (DSS) for grassland farming is a user-friendly online tool designed to assess the effects of current and alternative management practices and climate scenarios on key grassland parameters. These include yield, changes in soil carbon (C) stock, and environmentally relevant nitrogen (N) losses via leaching and gaseous emissions. The tool is based on the terrestrial ecosystem model LandscapeDNDC, which quantifies C and N turnover and exchange processes across the pedosphere, biosphere, hydrosphere and atmosphere from site, landscape up to national scales.
For site-scale simulations, users can access the DSS through a graphical web interface. As a first step, the location of the model application can be selected via an interactive map. By default, location-specific soil profiles (Bayerisches Landesamt für Umwelt) and current climate and projection data (ClimEx) from regional databases are used. Users can also choose between a quick and an expert mode. While the quick mode utilizes data from the regional database, the expert mode allows for further refinement of the climate and soil information.
As a final step, accurately defining grassland management actions is crucial for the quality of the simulations. Users can specify the frequency and timing of fertilization and cutting events per management season over a 10-year period. Additionally, fertilizer type (organic or mineral) and amount, fertilizer C and N content, cutting height, and mulching options can be manually adjusted. The total N applied per management season is automatically calculated to ensure compliance with the German Fertilizer Ordinance, which sets a maximum limit of 170 kg N of organic fertilizer per hectare per year.
Simulation results include yield, fodder quality, soil C balance, N use efficiency, N₂O and NH₃ emissions, and NO₃ leaching. These outputs are presented using a traffic-light system based on threshold values from the literature. The DSS allows users to compare different management scenarios and view projections of management and climate conditions up to 2050.
By bridging the gap between scientific research and agricultural practice, the DSS supports farmers and stakeholders to develop economically viable and environmentally sustainable grassland management strategies.

Speaker: Dr David Piatka (IMK-IFU - KIT)

19 Carbon footprints of dairy farming in pre-alpine regions of Germany: The climate impact of drained peatlands in milk production

Greenhouse gas (GHG) emissions from agriculture significantly contribute to climate change, with drained peatlands representing a substantial and often overlooked source, especially in Germany where 95% are drained for agriculture. Existing life cycle assessments (LCAs) of milk production often underestimate environmental impacts by neglecting these soil emissions. This study quantified the influence of peatland-derived emissions on the carbon footprint (CF) of milk production from three dairy farms located on drained peatlands in pre-alpine Bavaria, Germany.
We calculated CFs with and without peatland emissions, applying three methodological approaches: IPCC Tier 1, Tiemeyer et al. (2020) implied emission factors (EFs), and Tiemeyer et al. (2020) water table-dependent (WTD) response functions. A calculated near-natural peatland reference scenario was also established to contextualize these emissions. Our findings show that peatland emissions are a highly significant contributor, increasing milk CFs by over double on average, and becoming the dominant emission source. The chosen methodology notably influenced calculated CFs, with WTD-dependent approaches yielding higher estimates. Although subtracting baseline emissions from a near-natural scenario resulted in a minimal CF reduction (3.95% to 8.29%), the substantial impact of drained peatlands remained robust.
This study underscores the crucial importance of explicitly including peatland emissions in dairy LCAs for accurate environmental assessment. Results highlight the urgent need for targeted mitigation strategies, particularly water table management, to reduce the climate impact of agriculture on drained peatlands.

Speaker: Anna-Lena Müller

20 Estimating vegetation traits in pre-Alpine grasslands by combining multi-annual of in-situ data and UAV Imagery

Dear Editor,

I am pleased to submit an abstract for consideration of poster presentation in the International Grassland Conference 2025. The abstract is entitled “Estimating vegetation traits in pre-Alpine grasslands by combining multi-annual of in-situ data and UAV Imagery”.
Thank you very much for your consideration.

Sincerely,
Batnyambuu

Speaker: Dr Batnyambuu Dashpurev (IMK-IFU - KIT)

21 Full nitrogen balances for different cattle slurry fertilization techniques in a temperate grassland

Modern slurry application techniques have been shown to reduce ammonia losses, yet a comprehensive evaluation of their nitrogen (N)-related agronomic and ecological impacts is lacking. Therefore, we utilized 15N-labeled cattle slurry to examine traditional and modern application techniques regarding their effects on hydrological and gaseous N losses, plant N uptake, soil organic nitrogen (SON) formation, and total fertilizer N balances. Following the broadcast spreading of slurry, 43 % of fertilizer N was lost as gaseous emissions, regardless of precipitation. In contrast to broadcast spreading, significant total N emission savings were achieved by the broadcast application of diluted slurry combined with a reduced N supply (47 % emission reduction). Open slot injection at depths of 5 cm and 2 cm resulted in even greater emission reductions of 60 % and 74 %, respectively. Recent fertilizer was typically leached in minimal amounts, but applying diluted slurry increased nitrate leaching due to enhanced infiltration. Overall, the high productivity and plant N uptake were hardly affected by the application method, as over 90 % of the plants' N uptake relied on mineralized SON rather than recent fertilizer. The latter led to soil N mining, especially with broadcast spreading and slurry dilution, causing noticeably negative N balances (17–37 kg N ha-1 deficit per fertilization-harvest cycle). Using slurry injection contributed to additional SON formation, effectively offsetting the N deficit and thereby supporting the long-term maintenance of N-related soil functions.

Speaker: Sebastian Floßmann

22 Inventory of a pre-Alpine grassland region – stressors and drivers for yields and nitrogen losses

Grasslands are the basis for milk and meat production in Alpine and pre-Alpine regions, where climate warming is occurring twice as fast as in global average. Warmer and drier conditions have been found to lead to versatile effects on grassland productivity and yields depending on pedo-climatic conditions. Experimentally, it has been discovered that higher and cooler elevations benefit from warming in the absence of drought, whereas lower elevations are more vulnerable to yield losses under climate change. These findings are based on sites covering only a few discrete climatic, soil, and management conditions. In the present study, we compiled a highly detailed field-scale dataset including cutting dates (2018-2020) from remote sensing, informing regional grassland management routines of the biogeochemical model LandscapeDNDC which was applied in the pre-Alpine Ammer region (530 m a.s.l to 2200 m a.s.l., 4600 km²) in southern Germany. The strongest predictor of yields was the management intensity with an average yield increase of 1.3 t ha-1 a-1 per additional cut and associated manure application. We found a mean regional yield decrease of 5 % in the drought year 2018 compared to the year 2020 with average climatic conditions. Yields from extensive management were less sensitive to climatic parameters than the ones from intensive fields. Soil organic carbon had a positive effect on yields, especially in drier years. Yield increases of 0.18 to 0.24 t ha-1 a-1 per % increase in soil organic carbon were observed. The strongest correlation for nitrogen losses was also the management intensity. Nitrous oxide emissions were found to anti-correlate with yields, and correlate with soil organic matter. Nitrate leaching was overall very low (2 kg N ha-1 a-1). Our results illustrate the complex interactions between management, soil, and climate factors influencing C- and N-cycles in grassland, including differences in their importance in drought and non-drought years.

Speaker: Dr Carolin Boos (IMK-IFU - KIT)

23 Mechanism-based climate-smart soil management options

To achieve climate-smart soil management under the climate change crisis, mechanism-based management is essential for addressing agricultural productivity needs and enhancing carbon sequestration under contrasting land uses.
Based on a mechanistic assessment of grassland and cropland soils in a hillslope-floodplain system in Bavaria, this study provides several practical climate-smart soil management options targeted specifically to each land use.
For extensively managed grassland soils, minimal soil disturbance coupled with continuous organic amendments (such as grass biomass residues, manure, or slurry amendments) is recommended. These practices take advantage of the well-preserved subsoil structure that enriched in organic carbon (OC), nitrogen (N), and phosphorus (P), and the high nutrient availability deriving through active microbial processes and optimal C-N-P stoichiometric ratios.
Conversely, intensively managed cropland soils, characterized by lower plant biomass inputs and subsoil degradation due to deep-plowing and clear-harvesting practices, have reduced OC and N stocks, which organic fertilizers alone cannot fully replenish. Additional practices beyond avoiding deep-plowing and clear-harvest are thus necessary to reverse depleted OC stocks and mitigate P losses. Enhanced rock weathering (ERW) is suggested to be a viable climate-smart option, given its advantages for long-term carbon sequestration, sustained slow-release P supply, and soil acidity neutralization with minimal carbon losses.
This study provides targeted, mechanism-driven soil management recommendations that optimize agricultural productivity while preserving essential ecological functions in each land use in a hillslope-flood plain ecosystem in Bavaria, Germany.

Speaker: Jörg Völkel (Department of Geomorphology and Soil Science, Technical University of Munich)

24 Mechanistic insights of coupled C-N-P cycling in Bavarian soils

In the context of climate change and declining mineral phosphorus (P) fertilizer reserves, understanding carbon (C), nitrogen (N), and phosphorus (P) biogeochemical cycling under contrasting land uses is essential for sustainable climate-smart management. This study provides a comprehensive assessment of coupled C-N-P cycling within a hillslope-flood plain system in Bavaria, Germany. It investigates soil biogeochemical processes under long-term grassland and cropland management and evaluates how these processes are altered by an enhanced rock weathering (ERW) strategy aimed at CO2 removal.

The findings show that grassland soils exhibit higher organic carbon (OC), N, and organic phosphorus (OP) stocks compared to cropland soils. Although total P stocks are comparable across both land uses, cropland soils have a greater proportion of inorganic phosphorus (IP). Both OC and OP are predominantly enriched in fine soil fractions (<20 μm). Stoichiometric assessment combined with direct NanoSIMS observations suggests two distinct P retention pathways linked to OC and N. Grassland soils have a stronger coupling of C-N-P cycles driven by microbial processes, whereas cropland soils show weaker coupling due to abundant direct P-mineral complex formation without biological processes involved. The addition of ERW materials significantly influences OC cycling. Fresh ERW materials accelerate OC decomposition due to elevated soil pH, while weathered ERW materials sustain existing OC stocks and enhance new OC retention from plant residues.

This study gives mechanistic insights into C-N-P cycling dynamics under contrasting land uses and demonstrates how climate-smart strategies, such as ERW, can influence soil carbon sequestration and nutrient dynamics.

Speaker: Jörg Völkel (Department of Geomorphology and Soil Science, Technical University of Munich)

25 Mountain pastures

ABC

Speaker: Dr Elisabeth Ramm (IMK-IFU - KIT)

26 Scaling Up the Multiple Values of Grasslands: Land-Use Scenarios for Europe

Alpine and pre-Alpine grasslands represent ecologically rich and culturally important landscapes - shaped by long-standing human–nature interactions. By applying surveys in (pre-)Alpine Bavaria, we found that farmers and citizens not only attribute instrumental and intrinsic values, but predominantly relational values to grasslands. The results show that grasslands and their ecosystem services are valued for a variety of reasons on different locations, and point out the need for further investigations of of values associated with ecosystem services (Schmitt et al., 2022). Subsequently, by applying the Nature Futures Framework (NFF), we developed pathways that illustrate different trajectories toward achieving EU environmental and land-use policy goals based on the plurality of values (Raymond et al., under review). The (pre-)Alpine environment and grassland ecosystems are explicitly addressed across the scenario narratives: In Nature For Nature, extensive pastures and other semi-natural grasslands are not abandoned, but are maintained by free-roaming herbivores to prevent shrub and forest encroachment, sustaining vegetation structures vital for biodiversity. In Nature as Culture, traditional alpine grasslands are actively preserved as expressions of cultural heritage and identity, supported by strong community involvement in landscape stewardship. In Nature For Society, multifunctional grasslands are valued for their ecosystem services (e.g., flood retention and fodder production) and are integrated into land-use planning through sustainable intensification and agroecological strategies. By linking empirical insights from (pre-)Alpine grasslands with normative, value-based scenarios, this work illustrates how context-specific understandings of nature’s values can inform systemic and future-oriented land-use strategies. It underscores the importance of embedding diverse human–nature relationships found in (pre-)Alpine grasslands in land-use modelling and policy to shape desirable and nature-positive futures for Europe.

Authorship:
Schmitt, T.M.*, Riebl, R., Martín-López, B., Hänsel, M., Koellner, T., 2022. Plural valuation in space: Mapping values of grasslands and their ecosystem services. Ecosystems and People. https://doi.org/10.1080/26395916.2022.2065361

Raymond J., Schmitt, T.M.*, Tschol, M., Bakx, T., Brotons, L., Brown, Cl., Buitenwerf, R., Díaz-General, E., Ferreto, A., Kloibhofer, J., Laimer, T., Moreira, F., Pang, S., Plumanns-Pouton, E., Prestele, R., Smith, A., Svenning, J., Venancio, M., Rounsevell, M. Pathway narratives towards a nature-positive EU Land system: operationalizing the Nature Futures Framework for EU Policy objectives.

Speaker: Dr Thomas Schmitt (IMK-IFU - KIT)

27 The fate of fully 15N labelled organic fertilizer under different management intensities in 27 grassland sites across Germany

Fertilization strongly influences nitrogen (N) cycling and balance in managed grasslands. To investigate the long-term dynamics of organic N inputs, we applied fully 15N-labelled manure and slurry to 27 plots across three German regions under three different management intensities. Our findings show that slurry fertilization resulted in faster incorporation of fertilizer N into the plant-soil system and a slightly higher short-term plant uptake in the year of application with 11% (±1.4 SE) of fertilizer N in aboveground biomass for slurry and 1% (±0.3 SE) for manure. However, slurry also led to substantially higher N losses, particularly under intensive application. Unrecovered fertilizer N in intensive management was 47% (±1.8 SE), for medium management it was 20% (±4.9 SE) and for extensive management 11% (±3.9 SE). In contrast, manure under extensive management showed minimal N losses, with most fertilizer N (85% ±3.5 SE) retained in the soil pool. Over time, manure contributed to a more stable N reservoir, as across all treatments plants primarily sourced N from the soil 93%, with only 7% (±1.2 SE) derived directly from the fertilizer. These results highlight the trade-off between immediate N availability and long-term sustainability, emphasizing the role of organic fertilizer type and management intensity in shaping grassland N dynamics.

Speaker: Julia Kepp (IMK-IFU - KIT)

Wednesday 16 July

28 Ankunft & Registrierung/ Arrival & Registration Ankunft & Anmeldung (Campus Alpin, Kreuzeckbahnstr. 19, 82404 Garmisch-P.)

Exkursion/Excursion: Busfahrt nach Graswang/ Bus trip to Graswang

Exkursion/Excursion: Besuch der Messstation Graswang des TERENO (Terrestrial Environmental Observatories) Netzwerks im Ammer-Einzugsgebiet/ Visit to the Graswang measuring station of the TERENO (Terrestrial Environmental Observatories) network in the Ammer catchment area

Exkursion/Excursion: Fahrt und Aufstieg zur Brunnenkopfalm/ Drive and hike (around 45 min) to the Brunnenkopfhütte

12:00 Mittagessen bei der Brunnenkopfhütte/ Lunch at Brunnenkopfhütte

One meal and one drink will be provided per person.

Weitere Informationen zu der Hütte/further infromation about the hut:
https://brunnenkopfhuette.com/

Exkursion/Excursion: Besuch der Brunnenkopfalm (Wiederbeweidungsexperiment)/ Visit of the Brunnenkopfalm (re-grazing experiment)

Exkursion/Excursion: Abstieg und Rückfahrt nach Garmisch-Partenkirchen/ Descent and return to Garmisch-Partenkirchen

Thursday 17 July

08:00 Ankunft & Registrierung

Workshop: Begrüßung & Impulsvorträge

29 Vorstellungsrunde

30 Wie klingen Berglandschaften? Soundscapes messen und kartieren

Speaker: Dr Uta Schirpke

31 Grünland als Kohlenstoffspeicher – Humusmanagement im Grünland

Speaker: Prof. Martin Wiesmeier

32 Auswirkungen verschiedene Düngetechniken auf den Stickstoff-Kreislauf

Speaker: Dr Michael Dannenmann

33 Produktivität von Grünland im Klimawandel

Speaker: Dr Ralf Kiese

10:15 Kaffeepause

Workshop: Gruppenarbeit zur Entwicklung von Praxisleitfäden zu zentralen Grünlandthemen

12:00 Mittagessen

Workshop: Gruppenarbeit zur Entwicklung von Praxisleitfäden zu den zentralen Themen

14:00 Kaffeepause & Besichtigung der Poster zu den Grünland-Projekten SUSALPS, BLIK II, BioMON and KUHMUS_Beweidung

Workshop: Abschluss im Plenum mit Vorstellung der Gruppenarbeiten und Feedback

IMK-IFU Sommerfest (optional)