Evaluation of soil organic matter fractions methods – towards standardization and model compatibility
International workshop at the University of Göttingen
25th September 2015, 9 a.m. till 1 p.m.
Soil organic matter (SOM) fractionation methods have been developed to allow insights into SOM dynamics of ecosystems, assess pools of contrast availability and turnover and revealing drivers and mechanisms of C stability in soils. The number of fractionation schemes has increased drastically, most of them based on physical or chemical separation, partly also on biological. However, the most SOM properties present a wide range continuum. A major aim of SOM fractionation is the separation of homogeneous pools that are characterized by distinct properties, such as C turnover rates. Thus, the partitioning of SOM in distinct fractions is challenging and there have been little attempts to evaluate and to compare fractionation schemes and protocols. This limit the applicability of the fractionation approaches for initialisation and calibration of models of SOM dynamics.
The aim of this workshop is to evaluate existing and emerging SOM fractionation schemes in their ability to separate meaningful and as homogeneous as possible fractions. Indicators for the evaluation will be discussed and developed, taking into account the required workload of a fraction scheme and the applicability for modeling. In a subsequent ring trial various soil organic fractionation schemes will be tested in different labs using a common set of soil samples. Within the workshop we will kick off a ring trial to test and compare the most common SOM fractionation schemes used in labs all over the world.
Contributions exploring various fractionation schemes as well as approaches for their evaluation are highly welcome. Please contact Axel Don (axel.don(at)ti.bund.de).
C3-C4 Ring Trial
The ring trial will be a large comparative study on SOM fractionation methods. A wide range of soil types will be included in this ring trial. All provided soils will be sampled from ecosystems after C3-C4 vegetation change in order to get a natural 13C enrichment as a tracer for the new carbon. This 13C enrichment will allow to assess the success of the fractionation schemes. The fraction work will be performed in the participating labs, CN and 13C analyses of the fractions will be performed at the Thünen Institute in Braunschweig (free of charge). Participants of the workshop are invited to take part in this ring trial. The results will be evaluated and published together with the participants of the Ring Trial.
Axel Don (Thünen-Institute, DE)
Christopher Poeplau (Swedish Agricultural University Uppsala, SE)
Rolf Nieder (Technical University Braunschweig, DE)
Yakov Kuzyakov (University Göttingen, DE)
Registration for the SOMfrac workshop and the Ring Trial
For registration to the SOMfrac workshop and the Ring Trial please write an email to Axel Don (axel.don(at)ti.bund.de). For participants of the 5th Symposium of Soil Organic Matter this workshop will be free of charge. The number of participants is limited to 85. First come first serve.