Biochar has attracted a great deal of attention in the last years and it has been proposed as a geoengineering approach to promote soil carbon sequestration and thus help to mitigate global warming. Biochar addition to tropical soils resulted in the build up of soil carbon pools and has created a type of anthropic soils (Terras Pretas) which higher carbon stocks and fertility levels than the surrounding ferralsols. However, there are still many uncertainties that prevent biochar widespread use in soils, as biochars prepared from different sources and in different conditions (temperature, etc.) will behave in a different manner when added to soils with contrasting properties.

The main aim of this session is to bring together scientist that are trying to develop a better understanding on the benefits and limitations of using biochar as soil amendments. In this session we welcome studies both in Terra Pretas and in other types of temperate or tropical soils as well as studies including different scenarios in climate change.

Emphasis will be put in the effects of biochar on pollutant fate, carbon sequestration, soil nutrient transformation and leaching and soil microorganisms. Also, studies about the effect of different pyrolysis conditions on biochar are welcomed.

After the session, selected abstracts (orals and posters) will be proposed for an Special Issue of an International Journal.

Funding provided by Madrid regional government through project CCG10-UPM/AMB-5683 is greatly appreciated.

Invited presentations:
Decomposition and transformation of 14C labeled black carbon in soil
K. Kuzyakov, I. Bogomolova, and B. Glaser

Biochar effects on soils: overview and knowledge gaps
F.G.A. Verheijen, S. Jeffery, A.C. Bastos, and M. van der Velde

From organic matter to pyrogenic char to ash: the role of smouldering combustion in wildfires
G. Rein, R. Hadden, and C. Zarccone