The ELKH Research Centre for Astronomy and Earth Sciences (CSFK) has been awarded a HUF 54.1 million funding from the National Research, Development and Innovation Office (NRDI Office) for carrying out tasks in the three-year-long international project "Organic and inorganic carbon dynamics in calcareous soils," which started last year. The main goal of the French, Hungarian, Canadian, and Italian consortial collaboration is to characterize the qualitative and quantitative properties of organic and inorganic carbon phases in calcareous soils, compile a large-sample database, and harmonize and develop methodology related to the measurements. The exploration and examination of the relationships between different forms of soil carbon, including the development of research methodology, field sampling, and data evaluation, are conducted under the professional leadership of CSFK. Thanks to the large sample size and the diverse soil properties, the significance of the project is outstanding in terms of understanding organic matter stabilization in carbonate soils. The research can help to understand the processes behind the long-term carbon storage (stabilization) in soils, and thus the mitigation of global climate change.
The majority of Earth's terrestrial carbon stock is located in soils, so the carbon stored here is a very important element of the global carbon cycle. Therefore, more and more research is needed that thoroughly examine the temporal and spatial changes in the carbon content of the pedosphere and their driving forces in detail. Through these studies, it is possible to more accurately assess how changing climatic conditions will influence the fate of soil carbon stocks. It depends on this whether soils will become sinks or sources of atmospheric carbon dioxide (CO2), i.e., whether they will reduce or increase atmospheric CO2 concentration and thus mitigate or intensify global climate change.
Due to the mentioned reasons, researchers have dealt relatively extensively with the soils’ organic carbon forms and their role in the global carbon cycle (Figure 1) in recent decades. However, these studies mainly focused on carbonate-free, acidic soils, so much less attention was paid to carbonate soils and the organic matter stabilization processes occurring in them.
Figure 1
The main goal of the three-year project that began in 2022 is to characterize the quantitative (carbon and nitrogen content) and qualitative properties (stable carbon and nitrogen isotopes) of organic and inorganic carbon phases in calcareous soils. The task of the researchers of the French, Hungarian, Canadian, and Italian consortium is to compile a large-sample database consisting of topsoil samples (0-30 cm) and subsoil samples (> 30 cm) (Figure 2) with varying compositions, parent materials, and different land uses – under agricultural cultivation or uncultivated –, as well as to harmonize and develop the methodology related to the measurements. The organic matter that enters the soil is protected from microbial decomposition by its attachment to the mineral phase or inclusion in soil aggregates. The exploration and investigation of these relationships, including the development of research methodology, field sampling (Figure 3), and data evaluation, are conducted under the professional leadership of CSFK.
Figure 2
The investigation of organic matter stabilization mechanisms is carried out by researchers using a sequential physico-chemical fractionation procedure. With the help of this method, it is possible to separate organic matter pools with different stabilities and to identify physical processes, such as inclusion in aggregates, and chemical processes, such as adsorption on mineral surfaces, underlying organic matter stabilization.
Figure 3
Thanks to the large sample size and the diverse soil properties, the significance of the project is outstanding in terms of understanding organic matter stabilization in carbonate soils.
CSFK has been awarded a funding of 54.135.000 HUF from the Hungarian National Research, Development and Innovation Fund (NRDI Fund) for the implementation of the project entitled "Organic and inorganic carbon dynamics in calcareous soils" (2019-2.1.7-ERA-NET-2022-00037) as part of the 2019-2.1.7-ERA-NET call announced by the NRDI Office. The project has been implemented within the framework of the European Joint Programme ˝EJP SOIL – Towards Healthy, Resilient and Sustainable Agricultural Soils – 1st external call”.
Over the past year, CSFK researchers sampled nearly 60 soil samples from more than 20 sites in Hungary and analyzed their carbon content and stable carbon isotope composition. In the future, CSFK researchers will develop a methodology for the physico-chemical fractionation procedure necessary for the study of organic matter stabilization mechanisms and will carry out the procedure on selected soil samples, as well as the analysis of the individual organic matter fractions.