01368nam a2200181 a 450000100080000000500110000800800410001910000130006024501810007326002360025452005750049065000240106565300080108965300270109770000190112470000220114370000210116513398252022-01-12       2008    bl uuuu     u00u1 u    #d1 aSONG, G.  aComposition of the humin fraction and coarse char of Terra Preta de Índios soils by NMR, multivariate curve resolution and scanning electron microscopy.h[electronic resource]  aIn: ANNUAL INTERNATIONAL MEETING OF THE INTERNATIONAL BIOCHAR INITIATIVE, 2., 2008, Newcastle. Biochar, sustainability and security in a changing climate. Newcastle: International Biochar Initiative, 2008. p. 27-28. Ref. B21.c2008  aThe high and specific soil organic matter (SOM) contents of the Amazonian Dark Earths (Terra Preta de Índios), and their high contents of P and Ca provide high natural fertility to the soils. Biochar or pyrogenic carbon plays a major role for the SOM stability in these soils and it also provides a significant potential for carbon sequestration and sustainable ecosystems. There are several studies of the humic acids of Terra Preta de Índios soils, however, because of the difficulties in isolation, there is less awareness of humin, the most abundant SOM component.  aSoil organic matter  aNMR  aTerra preta de índios1 aNOVOTNY, E. H.1 aAZEVEDO, E. R. de1 aBONAGAMBA, T. J.