Soil GHG emissions from Danish lowland organic rich agricultural soil and the landscape to be

Human activities have transformed vast portions of terrestrial ecosystems into agricultural landscapes, leading to ecological, biological, and climatological consequences. Due to soil management practices, including drainage, tilling, and fertilization, agricultural soil has high greenhouse gas (GHG) emissions causing agriculture to be a key driver of climate change. One of the most effective and cost-efficient strategies for mitigating agricultural GHG emissions is targeted land-use change—restoring high-emission agricultural soils to their natural state – such as organic agricultural soil with high natural water table.

However, accurately estimating GHG emissions remains a challenge, as many underlying drivers are still not fully understood. In particular, the spatiotemporal variability of nitrous oxide (N2O) emissions demand high-resolution measurements across both space and time to capture the full GHG flux from agricultural landscapes.

This PhD project aims to quantify GHG emissions from organic agricultural soils over a period of land-use transition, as the soil is taken out of production. This will be achieved through an extensive monitoring approach:

An automated chamber system equipped with CO2, CH4, and N2O gas analyzers will be installed in the field to provide continuous in situ measurements across multiple seasons.

A fast-box method will be used to assess emissions at a broader landscape scale, capturing spatial variability.

Laboratory incubation experiments will be conducted using soil samples from the study site, where temperature and moisture conditions will be manipulated while measuring CO2, CH4, and N2O, along with the stable isotopes 13C/12C and 15N/14N.

By integrating high-frequency field measurements, large-scale spatial assessments, and controlled laboratory experiments, this PhD project will offer a comprehensive understanding of GHG emissions from organic agricultural soils and their transition toward natural conditions.