In this international consortium we aim to investigate how short and long-term agricultural management practices affect soil organic matter (SOM) persistence. We will combine long-term data with more in-depth analysis collected during this project in order to achieve this objective. With the Lab Geoecology and Physical Geography at RPTU, we focus on the organic farm in Tingvoll (Norway), where grass-clover leys are used to grow fodder for the farm animals. Here we will be focussing on the effect of (un)digested manure and increased precipitation on the soil organic matter pool at the Tingvoll farm. 

Scientists: Johanna Maria Zimmermann, Dr. Klaus Schützenmeister, Dr. Jeroen Zethof, Prof. Dr. Hermann Jungkunst, Dr. Tatiana Rittl (Norsøk)

Funding: German Federal Ministry of Education and Research

Website: https://www.embrapa.br/en/arroz-e-feijao/pesquisa/c-around

Are you interested in a bachelor or master thesis?

Within this project, there are two possible thesis projects open now:

1) Effect of digested manure on CO₂ and N₂O emissions from organic grass clover ley system

Carbon stored in soils is the major carbon stock on earth. Common agricultural practices often increase decomposition of this huge carbon storage, resulting in a release of CO₂, CH₄ and N₂O to the atmosphere. In order to reduce such emission, different types of land managements are studied to find the best practice. 

As part of C-arouNd project, we study the carbon and nitrogen cycles at an organic farm in Tingvoll (Norway). Grass-clover leys are used to grow fodder for the farm animals, whereby the collected manure is brought back on the fields either as-is or digested (after biogas production). Due to the biogas production, all easily available carbon is lost from the slurry, leaving a nitrogen rich material behind. We assume that this practices reduces the emissions of CO₂. However, the uncertainty is if the high nitrogen content is quickly lost as N₂O before it can be taken up by the plants. As part of the thesis, gas samples will be taken on a regular base in the field in Norway. Additionally, by taking samples of the grass clover we hope to assess the impact of digested slurry on plant growth and grass-clover composition. 

The main question we hope to answer with your MSc thesis is if digested manure is releasing less N₂O and CO₂ emissions from the soil than undigested manure during Norwegian summer conditions. 

Supervisors: Dr. Jeroen Zethof, Johanna Maria Zimmermann, Dr. Klaus Schützenmeister, Dr. Tatiana Rittl (Norsøk), Prof. Dr. Hermann Jungkunst

Contact: jeroen.zethof(at)rptu.de

2) Freeze-thaw effect on organic matter mineralization

Subarctic soils undergo regular freeze-thaw cycles over the year, which have an important impact on microbial activity in soils. It is known that upon thawing relative large amounts of CO₂ and CH₄ can be released by increased microbial activity, which is both an important contributor to climate change and a loss of local soil fertility. Therefore it is important to understand the underlying processes better and how land management practices can be adopted to reduce these losses.

As part of C-arouNd project, we study the carbon and nitrogen cycles at an organic farm in Tingvoll (Norway). Grass-clover leys are used to grow fodder for the farm animals, whereby the collected manure is brought back on the fields either as-is or digested (after biogas production). In this thesis, columns will be created from collected materials from the farm. Part of these columns will be undergo a freeze-thaw cycle, whereby we will sample gas and water samples on a regular base from both the freeze-thaw and control columns.

The main question we hope to answer in your thesis is if the use of digested and/or undigested manure is influencing the release of C and N from the soil during freezing conditions and upon thawing.

Supervisors: Dr. Jeroen Zethof, Johanna Maria Zimmermann, Dr. Klaus Schützenmeister, Prof. Dr. Hermann Jungkunst

Contact: jeroen.zethof(at)rptu.de