From charcoal to biochar: 10 years of progress in research on pyrogenic carbon in soils at IRNAS-CSIC

Comunicacion oral presentada Abstract number: S 1.37 ISMOM 2019 - 8th International Symposium on Interactions of Soil Minerals with Organic Components and Microorganisms: 23-28 june, Sevilla (Spain)

Charred biomass residues derived from incomplete combustions including wildfires significantly contribute to the pyrogenic carbon (PyC) or as it is also referred to as “Black Carbon” pool of soils [1].The production of PyC from vegetation fires could account for up to a quarter of the residual terrestrial C sink. Nevertheless its quantitative importance in the global C balance remained during decades contentious and thus PyC was rarely considered in global C cycle and climate studies [2]. From 2008 to 2011 researchers of the Pyrolysis team at IRNAS-CSIC developed several methods for the detection and quantification of PyC that were successfully applied to soils and sediments [3-5]. Furthermore they delved into the composition structure and properties of contrasting forms of PyC. Subsequently using pioneering 15N labelling experiments the fertilizing properties of N-enriched PyC materials were demonstrated [6]. These works were the prelude to the application of biochar (biomass that has been heated in a low oxygen environment in order to serve as soil amendment). During the last years the group has focused its efforts on: i) studying the relationship between the pyrolysis conditions and the properties of the produced biochars especially those of agronomic interest [7] ii) the risks (such as the polycyclic aromatic content [8] or microbial degradation [9]) and benefits of its application to different soils under Mediterranean climate conditions [10-11]. This knowledge is strictly needed to avoid potential long term damage in the ecosystems and to ensure its sustainability. [1] De la Rosa et al. 2015. J Soils and Seds. 15 745-747 [2] Santin et al. 2016. Glob Ch Biol. 22 76-91 [3] De la Rosa et al. 2008. Soil Sci Soc Am J. 72 258-267 [4] Knicker et al. 2008. Geoderma 147 69-74 [5] Knicker et al 2013. Soil Biol Biochem. 56 31-39 [6] De la Rosa and Knicker 2011. Soil Biol Biochem. 43 2368-2373 [7] De la Rosa et al. 2014. Sci Tot Env. 499 175-184 [8] De la Rosa et al. 2019. Sci Tot Env. 667 578-585 [9] De la Rosa et al. 2018. Sci Rep. 8 2896 [10]Paneque et al. 2016. Catena 147 280-287 [11] De la Rosa et al. 2018 Sci Tot Env. 613-614 969-976

MINEICO and AEI/FEDER are thanked for funding the on going projects CGL2016-76498-R and CGL2015-64811-P.