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Bo Tan - One of the best experts on this subject based on the ideXlab platform.
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Root diameter controls the accumulation of humic substances in decomposing root litter
Geoderma, 2019Co-Authors: Qun Liu, Liyan Zhuang, Rui Yin, Chengming You, Kai Yue, Bo Tan, Yang Liu, Li ZhangAbstract:Abstract The Humification of plant litter is a crucial step for the buildup of soil organic matter in terrestrial ecosystems. Yet, how environmental change and substrate quality affect root Humification still remains poorly understood. A two-year litterbag experiment was conducted to assess the root mass remaining and accumulation of humic substances in roots of three diameter classes (0–2, 2–5 and 5–10 mm) of two common subalpine tree species (Picea asperata and Abies faxoniana) at two elevations (3037 m and 3580 m) on the eastern Tibetan Plateau. No significant differences were found between elevation treatments in the concentration of humic substances. Both root mass loss and concentrations of humic substance, humic acid and fulvic acid decreased with increasing root diameter. Both fulvic acid concentration and Humification degree declined as root decomposition progressed but humic acid concentration exhibited an opposite trend. Our results reveal that the diameter-associated variations in accumulation of humic substances were substantially stronger than altitudinal and interspecific differences in decomposing root litters. These findings have important implications for carbon sequestration via root Humification in the subalpine forests experiencing snow-covered winter.
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The Mass Loss and Humification of Stumps and Roots in Masson Pine Plantations Based on Log File Records.
PloS one, 2016Co-Authors: Jiao Zhou, Bo Tan, Hui Liu, Wanqin Yang, Jian Zhang, Fei Duan, Meta Francis JustineAbstract:Stumps account for a large proportion of coarse woody debris in managed forests, but their decay dynamics are poorly understood. The loss of mass and the degree of Humification of the above-ground woody debris, below-ground woody debris, bark and root system (R1, 10 mm ≥ diameter > 0 mm; R2, 25 mm ≥ diameter >10 mm; 100 mm ≥ R3 > 25 mm; R4 > 100 mm) of Masson pine (Pinus massoniana) stump systems were evaluated in southwestern China in a chronosequence of plantations cut 1–15 years prior to the study. The results indicated that above-ground woody debris decomposed more quickly than below-ground woody debris and bark, whereas the degree of Humification followed the opposite trend. Compared with one-year stumps, the mass losses of 15-year stump systems were 60.4% for above-ground woody debris, 42.1% for below-ground woody debris, 47.3% for bark, 69.9% for R1, 47.3% for R2, 51.0% for R3, and 83.2% for R4. In contrast, below-ground woody debris showed a greater degree of Humification compared with other components in the stump system. Among the root system, fine roots (R1, diameter ≤ 10 mm) had the largest k value (0.09), whereas the decay rate of coarser roots (R2, R3, R4; diameter > 10 mm) increased with increasing root diameter. However, coarse roots showed a larger degree of Humification (0.2–0.6) than fine roots (0.3–0.4). These results suggest that below-ground woody debris and coarse roots may display a higher degree of Humification, showing greater short-term contributions to overall Humification when compared with the other components in the stump system.
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accelerated foliar litter Humification in forest gaps dual feedbacks of carbon sequestration during winter and the growing season in an alpine forest
Geoderma, 2015Co-Authors: Wanqin Yang, Bo TanAbstract:Abstract Can forest gaps lead to constrained litter decomposability by redistributing heat and moisture conditions, thereby increasing carbon sequestration from plant to soil via litter Humification in alpine forests? We studied mass losses, humic substances, humic acid, fulvic acids, as well Humification degrees and Humification ratios in six foliar litters with a field litterbag experiment from the gap center, canopy gap and expanded gap to the closed canopy in winter and the growing season in an alpine forest of the east Tibetan Plateau. Humification degrees of 18%–45% for birch, 15%–40% for fir, 8%–30% for willow, 14%–26% for cypress, 9%–25% for larch and 7%–19% for azalea foliar litter were observed in forest gaps and the closed canopy over one year of incubation. Small amounts of humic substances accumulated in winter, whereas considerable humic acid accumulated, but fulvic acid mineralized during the growing season. Compared with the closed canopy, foliar litter Humification in forest gaps was lower in winter but greater in the growing season, implying a dual role of forest gaps in carbon sequestration between winter and the growing season. Carbon sequestration could be accelerated in forest gaps. Reduced snow cover under a scenario of winter warming would stimulate soil carbon storage in these alpine forests.
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The responses of early foliar litter Humification to reduced snow cover during winter in an alpine forest
Canadian Journal of Soil Science, 2014Co-Authors: Wanqin Yang, Bo TanAbstract:Ni, X., Yang, W., Li, H., Xu, L., He, J., Tan, B. and Wu, F. 2014. The responses of early foliar litter Humification to reduced snow cover during winter in an alpine forest. Can. J. Soil Sci. 94: 453-461. Snow cover can be reduced by ongoing winter warming in alpine biomes, affecting foliar litter Humification, but few reports are available. To quantitatively clarify how early foliar litter Humification responds to reduced snow cover in winter, a field litterbag experiment was conducted in an alpine forest in southwestern China. Mass losses, ΔlogK, E4/E6, degrees of Humification and Humification rates of six typical local foliar litters were investigated at the snow formation, snow cover and snow melt stage under snowpack levels differing in depth (deep snowpack, medium snowpack, thin snowpack, no snowpack) from November 2012 to April 2013. The results indicated that 14-15% of willow (Salix paraplesia), 8-9% of fir (Abies faxoniana), 6-7% of birch (Betula albo-sinensis), 5-8% of cypress (Sabina saltuaria), larch (Larix mastersiana) and azalea (Rhododendron lapponicum) foliar litter was humified, which was about 50% of what decomposed during the first winter. Moreover, the early Humification of foliar litter (except for fir and birch) responded positively to the reduced snow cover, but mass loss exhibited negative responses. Such results suggest that reduced snow cover in winter would increase soil carbon or other material sequestration in the scenario of climate change.
Carlo Gessa - One of the best experts on this subject based on the ideXlab platform.
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Identification of organic matter from peat, leonardite and lignite fertilisers using Humification parameters and electrofocusing.
Bioresource technology, 2003Co-Authors: Luciano Cavani, Claudio Ciavatta, Carlo GessaAbstract:Abstract The organic matter extracted from peats (P), leonardites (Le) and lignites (Li) was characterised by Humification parameters and electrofocusing (EF). The degree of Humification and the Humification index might be used to distinguish P from Le and Li, but not Le from Li because they showed overlapped values, while the Humification rate could be used only for the identification of Le and EF profiles of P, Le and Li fertilisers revealed different band patterns: P samples did not show bands in the region with isoelectric point, pI>4.4; Le samples showed very intense bands in the region with pI>4.4; Li samples showed a very different band pattern with poorly resolved bands in the region with pI>3.8. P, Le and Li samples can be distinguished by combining Humification parameters and EF.
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Evolution of organic matter in sewage sludge: a study based on the use of Humification parameters and analytical electrofocusing
Bioresource Technology, 1993Co-Authors: M. Govi, Claudio Ciavatta, Carlo GessaAbstract:Abstract The degree of Humification (DH), Humification index (HI), and Humification rate (HR) were determined for seventeen samples of sewage sludges and composts from sewage sludges. The same samples, extracted with 0·5 M NaOH, 0·1 M Na 4 P 2 O 7 , and 0·1 M Na 4 P 2 O 7 adjusted to pH 7, were analyzed with analytical electrofocusing (EF). The results clearly show that the organic matter changes much more quickly during composting than during the anearobic digestion. It was also found that the ability of the alkaline solutions to solubilize the organic complexes was greater the higher the apparent isoelectric point and the greater the reproducibility of the analytical electrofocusing data.
Wiesław W. Sułkowski - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Humification processes occurring during sewage purification in treatment plants with different technological processes.
Water research, 2009Co-Authors: Justyna Polak, Mariola Bartoszek, Wiesław W. SułkowskiAbstract:The course of the Humification process of sewage sludge collected from three biologic-mechanical treatment plants with different treatment technologies was studied. The maturity of sewage sludge and its usefulness for agricultural purposes was also discussed. The physical-chemical properties of humic acids extracted from sewage sludge received from comparable stages of sludge purification were described. Changes of the sludge properties during sewage purification and the progress of the Humification process were investigated with EPR, IR and UV/VIS spectroscopic methods. The content of the elements and the carboxylic groups in humic acids extracted from each stage of the sewage treatment were also determined. It was found that the Humification processes take place in all three treatment plants but with different intensities resulting from the differences in the individual cleaning processes in these plants. The most intensive changes of physical-chemical parameters in the extracted humic acids were observed in the anaerobic digester where mesophilic fermentation occurs. The sludge oxygenation processes also significantly affect the course of the Humification process during sewage treatment.
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Effect of Humification processes on polyaromatic hydrocarbons concentration during wastewater treatment.
Water environment research : a research publication of the Water Environment Federation, 2006Co-Authors: Wiesław W. Sułkowski, Justyna Polak, Iwona Miształ, Jarosław Miształ, Mariola Bartoszek, Anna SułkowskaAbstract:The aim of the present work was to compare the concentration changes of polyaromatic hydrocarbons (PAH) and the course of Humification processes during wastewater treatment. Studies of samples from a biological-mechanical wastewater treatment plant in Sosnowiec-Zagorze (Poland) were carried out. Determination of PAH was performed both for wastewater sludge and sludge water. Observations of the course of Humification processes for humic acid fractions isolated from sludges were conducted. Analysis of PAH extracted from wastewaters and from sludge was performed by means of high-performance liquid chromatography. Investigations of Humification processes were conducted by electron paramagnetic resonance and nuclear magnetic resonance methods. The elementary composition changes in the structure of the extracted humic acids were determined. It was found that polyaromatic hydrocarbons appear during the processes of Humification. Their content in water decreased only after the process of sludge aeration; however, sludge water leaving the settlers was PAH-enriched.
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Spectroscopic studies of the progress of Humification processes in humic acid extracted from sewage sludge
Journal of Molecular Structure, 2005Co-Authors: Justyna Polak, Wiesław W. Sułkowski, Mariola Bartoszek, W. PapieżAbstract:Abstract The humic acids extracted from sludge collected from the digestion chamber and the sludge drying beds were studied. The sludge samples were collected, dried and humic acids were extracted. The progress of the Humification processes was studied with EPR, IR and NMR spectroscopic methods. For extracted humic acids, concentration of free radicals and g factor was determined with EPR. The presence of characteristic functional groups was confirmed with IR and NMR spectroscopy. To study the changes in content of the elements, the elemental analysis was performed to determine the percentage of carbon, hydrogen, nitrogen, sulfur and oxygen. Taking all the obtained results into account it was found that on the sewage drying beds, Humification processes take place in the sludge. In the first two weeks when the sludge on the drying beds an intensive enrichment of humic acids in free radicals takes place. This is the result of the intensive Humification process course after the stage in the fermentation chamber where the mesophilic fermentation takes place. Moreover, the humidity of sludge influences the intensive development of free radical concentration at the beginning of the storing period, whereas the Humification processes still continue.
Akira Watanabe - One of the best experts on this subject based on the ideXlab platform.
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characterization of the chemical composition of soil humic acids using fourier transform ion cyclotron resonance mass spectrometry
Geochimica et Cosmochimica Acta, 2015Co-Authors: Kosuke Ikeya, Rachel L Sleighter, Patrick G Hatcher, Akira WatanabeAbstract:Abstract The composition of humic acids (HAs) with varying degrees of Humification isolated from 10 common Japanese soils was characterized using negative ion mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry at 12 T. In particular, attention was paid to polynuclear aromatic components, which are more associated with the refractory nature of HAs and their resistance to biodegradation in soil than single C ring aromatic entities, such as lignin-like components, and aliphatic functionalities. Thousands of peaks were observed in the m / z range of 200–700, and molecular formulas were assigned to 817–2457 peaks in each sample. The molecular formulas having H/C and O/C ratios similar to those of lipid, protein, and other aliphatics with low double bond equivalents (DBE) of 0–7 were generally observed across the m / z range of 200–700. Although there were a number of molecular formulas having H/C and O/C values similar to those of lignin across the wide m / z range in the HAs with a low degree of Humification, most lignin-like molecular formulas in the larger m / z range (450–650) or irrespective of m / z were lacking in the HAs with middle and high degrees of Humification, respectively. These observations suggest a longer residence time for lignin monomers/dimers (and their derivatives; m / z 200–400) than larger lignin oligomers ( m / z 450–650) in HA structural domains. The number of molecular formulas having H/C and O/C values similar to condensed aromatics increased with increasing degree of Humification. The m / z and DBE values of condensed aromatic-like molecular formulas in the HAs with a lower degree of Humification were 17) expected to have at least 5 rings, increased with increasing degree of Humification and aromatic C content (evaluated by solid-state 13 C nuclear magnetic resonance spectroscopy), suggesting their contribution to the intrinsic recalcitrance of HAs in soil.
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Changes in the composition of humic acids in various upland field soils with a continuous application of an organic amendment as revealed by fractional precipitation analysis
Soil Science and Plant Nutrition, 2015Co-Authors: Shigeki Kawasaki, Kosuke Ikeya, Yuki Sugiura, Akira WatanabeAbstract:AbstractThe effect of the continuous application of an organic amendment (OA) on the accumulation and composition of humic acids (HAs) in various upland field soils was analyzed using a fractional precipitation technique. Fractionation patterns of HAs from plots treated with farmyard manure (FYM) or composted rice straw plus chemical fertilizer (CF) and from plots treated with CF alone were obtained by the step-wise addition of ethanol, 200–800 mL L−1, to HAs dissolved in 0.01 M sodium hydroxide (NaOH), and their degrees of Humification were compared. HAs with a higher degree of Humification precipitated in more dilute ethanol concentrations. The largest distribution shifted to a fraction that precipitated at a lower ethanol concentration with increasing degree of Humification of bulk HAs, without an accompanying decrease in the amount of fractions with lower degrees of Humification. A continuous OA application resulted in larger HA fractions with lower degrees of Humification in most of the fields. The p...
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composition of humic acids with respect to the degree of Humification in cultivated soils with and without manure application as assessed by fractional precipitation
Soil Science and Plant Nutrition, 2008Co-Authors: Shigeki Kawasaki, Nagamitsu Maie, Akira WatanabeAbstract:Abstract A fractional precipitation method with 0.01 mol L−1 NaOH–ethanol solutions was used to assess the temporal change in the composition of humic acids (HAs) in upland field soils with respect to the degree of Humification as expressed by the degree of darkening. A Typic Hapludult (Togo) and Pachic Melanudand (Kuriyagawa) with and without the application of cattle manure were examined. Humic acids were fractionated into five to eight fractions, and a fraction precipitated at a lower ethanol concentration tended to have a larger degree of Humification in each soil. The slight increase in the degree of Humification of Togo HAs in both the manured (40 Mg ha−1 year−1) and non-manured plots after 10 years was exhibited as a shift in the dominant fraction. The distribution pattern in the fractionation of Kuriyagawa HAs was similar between the initial soil and the manured (80 Mg ha−1 year−1) and non-manured plot soils after 19 years. However, the degree of Humification of the dominant fraction that was prec...
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Semiquantitative GC/MS analysis of thermochemolysis products of soil humic acids with various degrees of Humification
Organic Geochemistry, 2004Co-Authors: Kosuke Ikeya, Shuichi Yamamoto, Akira WatanabeAbstract:Abstract Thermochemolysis with tetramethylammonium hydroxide (TMAH) was conducted for 18 humic acids (HAs) obtained from a wide range of soils, and the yields and compositions of the released compounds were analyzed in terms of the degree of Humification and the proportions of C species estimated by 13C CPMAS NMR. Eighty-six peaks could be assigned on GC/MS chromatograms, and notable differences in the kind of compound assigned were not found among the HAs. The total yields of aliphatic compounds ranged from 0.40 to 4.2 mg/g. C12- to C18-even fatty acid methyl esters (FAMEs) accounted for 30–66% of the entire aliphatic compounds assigned, followed by C20- to C34-even FAMEs (4.8–47%), C9- to C33-odd FAMEs (11–26%), and C16- to C30-even dicarboxylic acid dimethyl esters (DAMEs; 0.3–9.1%). The total yields of aliphatic compounds decreased with decreasing gross alkyl C during the progress in the degree of Humification, although their proportion in gross alkyl C was small. On the other hand, the total yields of aromatic compounds ranged from 1.7 to 37 mg/g. Of these, 7.5–82% and 0.12–64% were phenol derivatives that were possibly derived from lignin and benzenepolycarboxylic acid polymethyl esters, respectively. The yields of phenol derivatives and stilbene compounds, possibly originating from lignin dimers, decreased with an increase in the degree of Humification, contrary to the increase in the proportion of aromatic C in total C. The yields of heterocyclic compounds, namely, indole and proline derivatives, were also higher in HAs with lower degrees of Humification. The variation in the yield of benzenepolycarboxylic acid polymethyl esters suggested parallel progression of oxidation with increasing degree of Humification. Aromatic compounds responsible for the high aromaticity and the dark color of HAs, such as quinones and polycyclic compounds, were not detected even in HAs with a high degree of Humification.
D M B P Milori - One of the best experts on this subject based on the ideXlab platform.
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soil organic matter Humification under different tillage managements evaluated by laser induced fluorescence lif and c n ratio
Soil & Tillage Research, 2011Co-Authors: T Martins, D M B P Milori, S C Saab, A M Brinatti, Jadir Aparecido Rosa, F A M Cassaro, Luiz F PiresAbstract:Abstract In this work is presented the use of the C/N ratio and the Laser Induced Fluorescence (LIF) spectroscopy for determining the Humification of soil organic matter (SOM) in an Oxisol under three different long-term tillage managements (no-tillage (NT), reduced tillage (RT) and conventional tillage (CT)). Humification of SOM was evaluated in the soil and its fractions (clay
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organic matter study of whole soil samples using laser induced fluorescence spectroscopy
Soil Science Society of America Journal, 2006Co-Authors: D M B P Milori, Cimélio Bayer, H V A Galeti, Ladislau Martinneto, Jeferson Dieckow, Martha Gonzalezperez, Julio Cesar SaltonAbstract:Fluorescence spectroscopy relies on the fluorescence emitted by rigid conjugated systems and thus can be used to assess the soil organic matter (SOM) Humification. This technique is generally applied to solution samples of humic substances, and so far no information exists about its applicability to whole untreated soil samples. The laser-induced fluorescence (LIF) spectroscopy is proposed as a novel technique to assess the organic matter Humification in whole soil samples. We sampled the 0- to 2.5-, 2.5- to 5-, 5- to 10-, 10- to 15-, and 15- to 20-cm layers of three Oxisols of long-term experiments located in two sites of the Brazilian Cerrado. The Humification index based on LIF spectroscopy (H L I F ) of whole soil samples showed a dose correlation with the Humification indexes A 4 /A 1 , I 4 6 5 /I 3 9 9 , and A 4 6 5 obtained after fluorescence spectroscopy analysis of the dissolved humic adds. The H L I F in soils under native cerrado or subjected to no-tillage increased from the top to the deepest layer, which is consistent with the deposition of labile organic matter from plant residues on the soil surface. The soils subjected to conventional tillage, however, showed relatively constant H L I F along the profile, possibly because homogenization imparted by disturbance of the arable layer. Accordingly, for the two top layers, the soils under no-tillage showed a lower H L I F than for conventionally tilled soils. Laser-induced fluorescence spectroscopy is a promising technique to assess Humification in whole soil samples, particularly in Oxisols, which due to high concentration of Fe 3 + are not feasible to electron spin resonance (ESR) and Carbon-13 nuclear magnetic resonance ( 1 3 C NMR) spectroscopy, unless previous treatment is employed.
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multimethod study of the degree of Humification of humic substances extracted from different tropical soil profiles in brazil s amazonian region
Geoderma, 2005Co-Authors: Andre Henrique Rosa, Marcelo Luiz Simoes, Luciana Camargo De Oliveira, Julio Cesar Rocha, Ladislau Martin Neto, D M B P MiloriAbstract:Abstract This work consisted of determining the degree of Humification of humic substances (HS) extracted from six different Amazonian soils collected from flooded and unflooded regions at different depths (0–10, 10–20, 20–40, and 60 cm). The humic substances were extracted according to procedures recommended by the International Humic Substances Society and characterized using elemental analysis, electron paramagnetic resonance (EPR), and fluorescence spectroscopy. The findings on semiquinone-type free radical concentrations in HS showed variations of 0.10–7.55×10 18 spins g −1 of carbon (g C) −1 , indicating considerable differences between the Humification levels of HS extracted from Amazonian soils. The results showed an average of 1.71±0.04×10 18 spins (g C) −1 , which is congruent with other data reported in the literature on Tropical soils. It was found that, on average, HS extracted from flooded soil contained higher semiquinone-type free radical concentrations than HS extracted from unflooded soils, indicating the influence of humidity in the Humification process of organic matter. The Humification process varies according to the profile, and the 10–20- and 0–10-cm profiles generally showed more humified HS. The degree of Humification of the HS studied here displayed a similar behavior when exposed to fluorescence (excitation at 465 nm) and EPR ( R =0.85). However, the low correlation between the C/H, C/O, and C/N atomic ratios and the semiquinone-type free radical concentration/fluorescence intensities indicated that data obtained by these techniques with regard to the degree of Humification of HS may lead to different conclusions.