Lessons from the Terra Preta de Índios of the Amazon region for the utilisation of charcoal for soil amendment

Abstract

Neste trabalho faz-se a divulgação do potencial de carvões e resíduos orgânicos parcialmente carbonizados visando obter materiais que mimetizam a matéria orgânica do solo das Terras Pretas de Índio da Amazônia, e que sirvam como condicionadores de solo e seqüestrem carbono de forma recalcitrante e reativa. Pesquisas desenvolvidas por grupos brasileiros e estrangeiros têm contribuído para o entendimento do surgimento e utilização das Terras Pretas de Índio da Amazônia. Aqui são divulgados resultados de estudos químicos no sentido do desenvolvimento do conhecimento científico e tecnológico e de inovação no aproveitamento de subprodutos orgânicos, principalmente de indústrias de biocombustíveis, carvão vegetal metalúrgico e outros, buscando imitar a excelente performance da chamada Terras Pretas de Índio da Amazônia.The potential of charcoal and of partially combusted organic waste to mimic the soil organic matter of the Terras Pretas de Índios (Amazonian Dark Earths) from the Amazon Region is discussed. These materials serve as soil conditioners and as sequesterers of carbon in recalcitrant and in reactive forms. Studies carried out by Brazilian and by international groups have contributed to the emergence of an awareness of the compositions and of the uses of these materials. In this contribution we report on chemical studies that are leading to the development of a scientific and technological awareness, and of innovations that will have value in finding novel uses in applications to soil of chars from organic wastes such as those from the biofuel industry, and from metallurgical and various coal plant residues.

Biochar: Pyrogenic Carbon for Agricultural Use - A Critical Review

“…polycondensed aromatic rings) associated with carbonized products, usually after oxidative (chemical-; thermal-or photo-oxidation) removal of operationally defined non-pyrogenic material, however the use of multivariate mathematical tools in spectroscopic data, e.g. Multivariate Curve Resolution, can also provide interesting results about C speciation -pyrogenic and non-pyrogenic C (Novotny et al, 2009) without requiring the removal of non-pyrogenic material. Molecular marker techniques, in turn, quantify specific compounds produced during biomass carbonization, e.g.…”

“…This correction however assumes that the mass ratio of BPCA/pyrogenic C is constant, which was not properly evaluated for a broad spectrum of charred materials or weathered coal, which is already partially oxidized to aromatic carboxylic acids (Glaser et al, 2002;Kramer et al, 2004;Novotny et al, 2007Novotny et al, , 2009Maia et al, 2011;Linhares et al, 2012;Araujo et al, 2014).…”

“…The CEC depends mainly on: the content and properties of volatile matter for low carbonized biochar (Mukherjee et al, 2011), however due to the lability of this fraction, this effect is probably transient; the cooling of biochar with O 2 supply can oxidize it, generating carboxylic functionalities (Spokas et al, 2012); the aging of biochar also generates these functionalities (Cheng et al, 2006;Novotny et al, 2007Novotny et al, , 2009Heitkötter and Marschner, 2015). On the other hand, the anionic exchange capacity decreases with aging (Cheng et al, 2008); d. Sorption of nutrients and heavy metals (Beesley et al, 2011;Kookana et al, 2011;Melo et al, 2013): the adsorption of hard Lewis acids (e.g.…”

“…Two developments have sparked particular interest in using biochar. Firstly, the discovery of the Indian Black Earths (Terra Preta de Índio) suggests that one of the reasons for the extraordinary fertility of these soils is the high C content (up to 15 %), mainly in the form of pyrogenic C, as a result of ancient human activity in the Amazon (Madari et al, 2003;Novotny et al, 2009). A key process in the formation of Terra Preta was pyrolysis, which catalysed the transformation of organic material, "locking" the C in the form of charcoal.…”

Nutrients in Amazonian Black Earth from Caxiuanã Region

“…The abandonment of human activities in settlements does not affect chemical residue remains in soils. The potential validity of the chemical analysis of soil to interpret archaeological finds lies in its ability to predict significant features based on (i) the chemical signatures of total concentrations of multielements such as Ba, Ca, P, Zn, Cu and Pb in soils; 1 (ii) the chemical signatures of floor samples in the Maya region; 2,3 (iii) the available nutrients in soils from the Brazilian Amazon basin, [4][5][6][7][8] known by designations such as black earth, Indian black earth, anthropogenic black earth, archaeological black earth, Amazonian black earth (ABE) 9,10 or Amazonian dark earths. 11,12 The area in which ABE occurs is characterized by well-drained soil, running water and located in a particular geographical setting from which the surrounding areas can be clearly observed.…”