Charred organic carbon in German chernozemic soils

Abstract

Summary Burning vegetation produces partly charred plant material which subsequently could contribute to the highly refractory proportion of soil organic matter. The presence of charred organic carbon (COC) was investigated in 17 horizons originating from nine soils from Germany and the Netherlands using a suite of complementary methods (high‐energy ultraviolet photo‐oxidation, scanning electron microscopy, solid‐state 13C nuclear magnetic resonance, lignin analysis by CuO oxidation). Charred organic carbon could not be detected in the A horizons of an Alisol and a Gleysol, but it contributed up to 45% of the organic carbon and up to about 8 g kg–1 of the soil in a range of grey to black soils (Cambisol, Luvisol, Phaeozem, Chernozem and Greyzem). All these soils have chernozemic soil properties (dark colour, A–C profile, high base saturation, bioturbation). A 10‐km colour sequence of four chernozemic soils, which were very similar in chemical and physical properties, showed a strong relation between colour and the content of COC. This suggests that the COC affects mainly soil colour in the sequence studied. Finely divided COC seems to be a major constituent of many chernozemic soils in Germany. These results suggest that besides climate, vegetation and bioturbation, fire has played an important role in the pedogenesis of chernozemic soils.

Biochar: Pyrogenic Carbon for Agricultural Use - A Critical Review

“…The same is true for pyrogenic C in other soils where the intentionality of soil improvement is not confirmed, e.g. : Chernozems (Schmidt et al, 1999;Ponomarenko and Anderson, 2001), Mollisols (Glaser and Amelung, 2003) soil charcoal derived from wildfire or anthropic fires (Knicker, 2011;Vleminckx et al, 2014).…”

Prehistoric alteration of soil in the Lower Rhine Basin, Northwest Germany—archaeological, 14C and geochemical evidence

“…Satellite images and soil maps showed that the apparently uniform, regional cover of Chernozems is in fact a patchwork of grey (Greyzems) and black soils (Chernozems). Neither relief, parent material nor climate could explain this small-scale distribution and a prehistoric human influence has been postulated (Schmidt et al, 1999Gehrt et al, 2002). We hypothesise that prehistoric fire-based agriculture may have contributed large amounts of charred organic matter, which could have found its way onto and into the agricultural soils.…”

“…Black carbon was measured at CSIRO laboratories, Adelaide, Australia in 11 samples taken from Luvic Phaeozem pits and Bht horizons. Analytical details are reported in Schmidt et al (1999). Briefly, charred organic carbon was analysed after removal of less stable soil organic matter via high-energy UV photo-oxidation by 13 C nuclear magnetic resonance (NMR).…”

Storage and stability of organic matter and fossil carbon in a Luvisol and Phaeozem with continuous maize cropping: A synthesis

“…This is small compared to other pasture and agricultural land on the globe (Schmidt et al, 1999;Glaser and Amelung, 2003;Rodionov et al, 2006). Here, usually between 5% and 15% of total soil OC can be assigned to BC.…”