Humic Acid Formation in Artificial Soils Amended with Compost at Different Stages of Organic Matter Evolution

Abstract

A composting process was conducted under optimal conditions for 150 d, obtaining three biomasses at diff erent levels of maturity: raw material (RM), fresh compost obtained after 11 d of composting (FC), and evolved compost (EC) obtained after 150 d of composting. During the composting process, HAs were extracted and fully characterized by mass balance, DRIFT, and 1H and 13C-nuclear magnetic resonance spectroscopy. Each compost sample was incubated for 180 d in an artifi cial soil, after which HA extraction was repeated and characterized. To compare composts containing diff erent amounts of labile organic matter (OM), an equal amount of unhydrolyzable OM was added to the soils. Our results indicated that compost HAs consist of a biologically and chemically stable fraction (i.e., the unhydrolyzable HA [U-HA]) and a labile fraction, whose relative contents depended on the composting duration. Humic acid from more EC contained a higher amount of recalcitrant fraction (aromatic carbon) and a lesser amount of labile fraction (aliphatic carbon) than HA from RM and FC. Th ese results suggest that the humifi cation process during composting preserves the more recalcitrant fraction of the compost-alkali soluble/acid insoluble fraction (HA-fraction). Incubation of composts in soil showed that due to the higher labile fraction content, HAs from raw material were more degraded than those from EC. Th e abundance of labile carbon of soil amended with less-evolved compost (RM and FC) allowed the more recalcitrant fractions of U-HA to be more preserved than in EC. Th ese results suggest that lessevolved compost could contribute more than well evolved compost to the stable soil OM.

Composites containing acetylated wheat B-starch for agriculture applications

“…Thus, if the substrate is to be used for growing plants after biodegradation, dissolved mineral salts (ions) must be added on a continual basis. Carbon of soil organic matter ranged from 24.8 to 30.4% in the growing substrate, on the surface of films or Adani and Spagnol (2008), who found 41.1% for fresh compost and 22.7% for compost stored 150 days. When biodegradation is successful, a rise in BR and a slight rise in MBC-MW can be seen.…”

Chlorpyrifos-methyl solubilisation by humic acids used as bio-surfactants extracted from lignocelluloses and kitchen wastes

“…cutin and suberin from plants). Biomass HAs also contain raw or slightly degraded fractions such as carbohydrates, polysaccharides and fatty acids (Adani and Spagnol, 2008;Salati et al, 2011).…”

Artificial soils to assess temperature sensitivity of the decomposition of model organic compounds: effects of chemical recalcitrance and clay-mineral composition

“…Artificial soils are widely used in the horticultural industry to generate large amounts of potting media, and in engineering to create soils with known chemical and physical properties (Guest et al , 2001). The use of artificial soils, however, in scientific research in biogeochemistry is limited (Ellis, 2004; Adani & Spagnol, 2008). The advantage of using carefully constructed artificial soils for scientific research is the ability to control and replicate soil characteristics and to vary the properties of interest while strictly controlling other soil characteristics.…”