Search results for "HuMu"
showing 10 items of 132 documents
Humic substances along the profile of two Typic Haploxerert
2002
Abstract In Vertisols, organic matter contributes to soil colour by formation of organo-mineral complexes and affects morphological, physico-chemical, biological and biochemical properties. Turbation may affect the chemical and structural composition of the most stabilised fractions of soil organic matter (SOM), i.e., humic substances (HS). The objectives of this study were to: (1) characterise SOM in two Vertisols (V1 and V2) developed under Mediterranean climate in Italy, using some HS characteristics as indicators of SOM turnover in Vertisols, and (2) explore possible differences related to the pedomorphologic conditions of the area under which two soils have formed. SOM evolution along …
Effect of climate and vegetation on soil organic carbon, humus fractions, allophanes, imogolite, kaolinite, and oxyhydroxides in volcanic soils of Et…
2007
A soil sequence along an elevational gradient ranging from subtropical to subalpine climate zones in the Etna region (Sicily, southern Italy) was investigated with respect to organic C, kaolinite, and crystalline to noncrystalline Al and Fe phases. Special emphasis was given to the stabilization of soil organic carbon (SOC) and its interaction with the inorganic phases. The soils were variations of Vitric Andosols that developed on a trachy-basaltic lava flow with an age of 15,000 years. Two main vegetation systems dominated the sites: at the lower sites, it was mainly maquis vegetation and, at the higher elevated sites, predominantly coniferous forest. The concentration of SOC in the topso…
Characterisation of humic acids in fen peat
2020
Fens store significant amounts of organic matter and thus are of high importance from the perspective of the organic carbon biogeochemical cycle. Fen peat comprises moderately to highly decomposed higher plant remains with relatively high mineral matter content. Humic acids form the major part of fen peat organic matter; they are also the most refractory and recalcitrant natural substances to degradation, and thus they contain essential information regarding mire and peat development over large periods of time as well as the organic carbon biogeochemical cycle. Moreover, humic substances in fen peat are a prospective resource for applications in agriculture and other sectors. The aim of thi…
Sur la présence de matières organiques mésocénozoïques dans des humus actuels (bassin de Chaillexon, Doubs, France)
1998
Abstract The optical analysis in the Chaillexon watershed (Doubs, France), of the present soils' humus layers' organic matter points out the contribution of Meso-Cenozoic organic matter in addition to the one produced by vegetal cover. Their relative occurrence varies in each layer: in the reverse of that of vegetal organic matter, the relative amount of Meso-Cenozoic organic matter increases according to the depth. That result shows that the total organic matter amounts in soils (and its evaluation) do not only depend on the net primary production and that geological formations have to be taken into account. Moreover, it suggests that present and past detrital supplies are concerned with ‘…
A microcosm study on the respiration and weight loss in birch litter and raw humus as influenced by soil fauna
1988
The effect of diverse soil fauna (Collembola, Acari, Enchytraeidae, Nematoda) on decomposition of dead organic matter was studied in microcosms containing (1) birch leaf litter, (2) raw humus of coniferous forest and (3) litter on humus. Total respiration (CO2 evolution) was monitored weekly, and mass loss, length of fungal hyphae (total and metabolically active) and survival of animal populations were checked at the end of weeks 12 and 21–22 from the start of experiment. Animal populations established themselves well during the incubation. At the end of the experiment some replicates containing litter had microarthropod densities of up to 500 specimens per microcosm, corresponding to a fie…
Formation and Changes of Humic Acid Properties during Peat Humification Process within Ombrotrophic Bogs
2012
Studies of the living organic matter humification process are essential for understanding the carbon biogeochemical cycle. The aim of this study is to analyze relations between the properties of peat, peat humic acids and peat humification degree. The analysis has been done on samples of humic substances extracted from peat profiles in two ombrotrophic bogs and relations between peat age, decomposition and humification degree, botanical composition and properties of peat humic acids (elemental, functional composition) were studied. The found variability of peat properties is less significant than differences in the properties of peat-forming living matter, thus revealing the dominant impact…
Genesis of Peat Humic Acid Structure and Properties Within Bog Profiles
2012
Studies of living organic matter humification process are essential for understanding of carbon biogeochemical cycle, and considering this, the aim of this study is to analyse relations between properties of the peat, peat humic acids (HAs) and humification degree on example of analysis of two bog profiles in ombrotrophic bogs to identify the links between peat age, decomposition and humification degree, botanical composition and properties of peat humic acids (elemental, functional composition). The found variability of peat properties is much less than the significant differences in properties of peat-forming living matter, thus stressing the dominant impact of humification process on pea…
Peat humic acid properties and factors influencing their variability in a temperate bog ecosystem
2013
Studies of the properties of soil organic matter are essential for understanding the humification reactions and soil diagenesis processes. The aim of this study is to analyse properties of peat and peat humic acids as well as factors influencing their variability. Humic acids isolated from an ombrotrophic bog peat profile were used as study objects. Relations among peat age, decomposition and humification degree, botanical composition, and properties of peat humic acids (elemental, functional composition, spectral characteristics) were studied. The variability of peat properties was found to be less significant than the differences in the properties of peat-forming living matter, which indi…
Characterization of Humic Acids from Raised Bog Peat
2014
Abstract Humic substances form most of the organic component of soil, peat and natural waters, but their structure and properties are very much dependent on the source. The aim of this study was to characterize humic acids from raised bog peat to evaluate the homogeneity of humic acids isolated from the bog bodies and to study peat humification impact on the properties of humic acids. Peat humic acids (HA) have an intermediate position between the living organic matter and coal organic matter, with their structure formed in a process where the relatively labile moieties (carbohydrates, amino acids, etc.) are destroyed, and thermodynamically more stable aromatic and polycyclic structures eme…
Effect of Cd-containing wood ash on the microflora of coniferous forest humus
2000
The use of wood ash in forestry has been questioned because the cadmium (Cd) concentration of ash, which varies between 1 and 20 mg kg(-1) ash, exceeds the level allowed for fertilizers (3 mg kg(-1)) used in agriculture. To investigate the combined and separated effects of Cd and ash on the forest humus microflora, pumice or wood ash, spiked with a water-soluble (CdCl(2)) or -insoluble (CdO) form of Cd at three levels (0, 400 and 1000 mg kg(-1)), were applied at a fertilization level of 5000 kg ha(-1) in a laboratory microcosm study. The trial consisted of 60 microcosms (five replications per treatment), which were incubated in darkness at +20 degrees C and a constant relative air humidity …