- 1Norwegian University of Life Sciences, The Faculty of Environmental Sciences and Natural Resource Management and , Soil Science , Aas, Norway (tonje.aurland@nmbu.no)
- 2Norwegian Institute for Bioeconomy, Department of Soil Quality and Biogeochemistry, N-1430 Aas, Norway
- 3Norwegian Institute for Bioecenomy, Department of Grain and Forage Seed Agronomy, N-2849 Kapp, Norway
Decomposition and stabilization of organic C in soils of different cultivation systems
Soil organic carbon (SOC) is an important component of the global carbon stock, and supports functions related to soil health. It is therefore of great importance that we invest in new methodologies and research on increasing SOC stocks globally. On a farm-level, conservation agriculture aims to manage SOC content by, for example, using cover crops, crop rotations or minimal tillage.
The aim of our study is to investigate the C sequestration potential of different farming systems as well as their efficiency at stabilizing C from plant residue inputs. To do so, we incubated using 13C labeled plant material in field plots under contrasting long-term management histories. The incorporation of 13C into mineral associated organic matter (MAOM) and particulate organic matter (POM) was determined by physical size fractionation followed by isotope ratio mass spectrometry. Furthermore, the microbial carbon use efficiency was investigated with stable isotope probing using 18O-H2O.
The 13C labeled plant material was incubated in situ with soil using litter bags for one growing season, at the long-term experiment (LTE) of NIBIO Apelsvoll. The LTE was established in 1989, with four treatments included in this study. These treatments are a long-term and a short-term conservation agriculture system, as well as conventional crop production and a forage production system. The treatments are replicated “mini-farms”, with 4-year crop rotations and different management strategies.
Preliminary results show that the forage production system has the highest soil C content at 3%, which is significantly higher than in the other systems. Additionally, there are significant differences in the weight fractions of MAOM and POM between systems. Carbon and isotopic analyses of these fractions will be presented and discussed.
How to cite: Storholt, T. A., Dörsch, P., Eischeid, I., Budai, A., and Rasse, D.: Decomposition and stabilization of organic C in soils of different cultivation systems , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18800, https://doi.org/10.5194/egusphere-egu25-18800, 2025.
