• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.42-51
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• 2004

Peat humin(p-Humin), humic acid(p-HA) and fulvic acid(p-FA) were isolated from Canadian Sphagnum peat moss by dissolution in 0.1M NaOH followed by acid precipitation. After purification cycles, they are characterized for their elemental compositions and, acid/base properties. Functionalities and carbon structures of the humic fractions were also characterized using FT-IR and solid state $^{13}C$-NMR spectroscopy. Those results are compared with one another and with soil humic substances from literatures. Main purpose of this study was to present a chemical and spectroscopic characterization data of humic substance from peat moss needed to evaluate its environmental applicability. The relative proportions of the p-Humin, p-HA and p-FA in the peat moss was $76\%,\;18\%,\;and\;3\%$, respectively, based on the total organic matter content ($957{\pm}32\;g/kg$). Elemental composition of p-Humin were found to be $C_{1.00}H_{1.52}O_{0.79}N_{0.01}$ and had higher H/C and (N+O)/C ratio compared to those of p-HA($C_{1.00}H_{1.09}O_{0.51}N_{0.02}$) and p-FA($C_{1.00}H_{1.08}O_{0.65}N_{0.01}$). Based on the analysis of pH titration data, there are two different types of acidic functional groups in the peat moss and its humic fractions and their proton exchange capacities(PEC, meq/g) were in the order p-FA(4.91) >p-HA(4.09) >p-Humin(2.38). IR spectroscopic results showed that the functionalities of the peat moss humic molecules are similar to those of soil humic substances, and carboxylic acid(-COOH) is main function group providing metal binding sites for Cd(II) sorption. Spectral features obtained from $^{13}C$-NMR indicated that peat moss humic molecules have rather lower degree of humification, and that important structural differences exist between p-Humin and soluble humic fractions(p-HA and p-FA).

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.128-136
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• 1998

Most of total nitrogen in the surface soil exists in organic forms, of which amino acid-N is the major fraction. By-product fertilizers provide soil with humic substances, and humic acid is an essential component of humus. Amino acids(AAs) are easily converted to inorganic-N forms and thus play an important role in N fertility. This experiment was conducted to investigate the contents and distributions of AAs in humic acids which were extracted from the commercial by-product fertilizers of different composting materials. Total contents of AAs in humic acids ranged from 1.2 to 5.6%, of which neutral AAs were the highest with ranges of 0.8~4.5%. AAs contents in fertilizers composted from the plant residues such as leaf litter, sawdust and bark were in an order of neutral>acidic>basic AAs. In contrast, those from animal wastes, such as poultry and pig manures, were in an order of neutral>basic>acidic AAs. Distributions of total, acidic and neutral AAs were in the respective order of leaf litter>sawdust>pig manure>poultry manure>peat, bark>sawdust>leaf litter>peat and leaf litter>sawdust>bark>peat. Distributions of the basic AAs were in the reversed order of the acidic AAs. In bark fertilizer with increasing compost maturity, contents of the acidic AAs were increased in compensation for the decreases in those of neutral and basic AAs. Results demonstrated that distributions of amino acids in humic acid of by-product fertilizers were different from composting raw materials and degrees of humification.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.301-306
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• 1988

Contents and distribution of amino acids in the hydrolysates of humic acids extracted from straw of rice and barley at three different dates during decomposition were examined. The results obtained from this study may be summed up as the following: 1. There are differences between the humic acid hydrolysates from rice straw and barley straw in regards of composition of humic acids and distribution of amino acids. 2. Neutral amino acids as a group occupy the largest share, followed by acidic amino acids and basic amino acids. 3. The total amount of amino acids per gram of humic acid is greater in straw of rice than in straw of barley. 4. With the humification progressing the content of lysine increases, but the content of histidine decreases. In general glycine, glutamic acid, aspartic acid, alanine and leucine constitute the 5 predominant amino acids in all hydrolysates. 5. Arginine is not detected at all in any of the hydrolysates of humic acids obtained from humified materials. 6. The presence of phenylalanine and tyrosine is an evidence for the aromatic characteristics of humic acids.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1623-1623
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• 2001

Composting is a biological method used to transform the organic waste into stable, humified organic amendments. Humification is indicated as the key factor in improving the quality of compost, because of the importance of humic substances to soil ecology, fertility and structure, and their beneficial effects on plant growth The compost constituents vary widely, however, the degree of maturity is very important factor in compost quality. So this experiment carried out to determine the rapid estimation of the quality in cattle, pig, chicken and waste composts using near infrared reflectance spectroscopy(NIRS). Near infrared reflectance spectra of composts was obtained by Infra Alyzer 500 scanning spectrophotometer at 2-nm intervals from 1100 to 2500nm. Multiple linear regression(MLR) or partial least square regression (PLSR) was used to evaluate a NIRS method for the rapid and nondestructive determination of humic acid contents in composts. The results summarized that NIR spectroscopy can be used as a routine testing method to determine quantitatively the humic acid content in the compost samples ondestructively. Especially, we supposed that absorbance around 2300nm is related to humic acid as a factor of compost maturity. However the NIR absorption approach is empirical, it actually requires many combinations of samples and data manipulations to obtain optimal prediction.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.123-127
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• 2003

Changes in pyrene partitioning due to mineral surface adsorptive fractionation processes of humic substances (HS) were examined in model environmental systems. For purified Aldrich humic acid(PAHA), carbon-normalized pyrene binding coefficients ( $K_{oc}$ ) for the residual (i.e., nonadsorbed and dissolved) PAHA components were different from the original dissolved PAHA $K_{oc}$ , value prior to contact with mineral suspensions. A positive correlation between the extent of pyrene binding and weight-average molecular weight (M $W_{w}$) of residual PAHA components was observed, which appeared to be unaffected by the specific mineral adsorbents use and fractionation mechanisms. A similar positive correlation was not observed with the adsorbed PAHA components, suggesting that conformational changes occurred for the mineral-associated components upon adsorption. Nonlinear pyrene sorption to mineral-associated PAHA was observed, and the degree of nonlinearity is hypothesized to be dependent on adsorptive fractionation effects and/or structural rearrangement of the adsorbed PAHA components.s.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.70-78
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• 1998

Dissipation, adsorption and desorption of oxadiazon were examined in two soils containing different amounts of soil organic matter. In addition, reactivity of oxadiazon with humic monomers was searched to clarify binding mechanism of oxadiazon to soil organic matter in the presence of a laccase of Myceliophthera thermophila. Half lives of oxadiazon were 38 days in Soil I and 45 days in Soil II. Freundlich constant, k values of fresh soils were higher than those of oxidized soils. Adsorption rates of oxadiazon were increased 17.1% in Soil I and 9.3% in Soil II in the presence of a laccase but no significant increase was observed in oxidized soils. Desorption rates of oxadiazon in fresh soils were lower than those in oxidized soils. Desorption rates of adsorbed oxadiazon in soils addes with the enzyme were not changed in oxidized soils but decreased in fresh soils. The herbicide oxadiazon alone underwent no transformation by a laccase but in the presence of catechol, guaiacol and gallic acid as humic monomer, transformation rates of it were from 20% to 24%.

• Journal of Soil and Groundwater Environment
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• v.26 no.5
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• pp.49-59
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• 2021

The effects of green manure crops, hairy vetch and sesban, supplemented with HS (humic substance) on biological soil health indicators was studied in a pot containing two kinds of reclaimed soil previously contaminated with petroleum hydrocarbons; a soil remediated by land-farming (DDC) and another soil by low-temperature thermal desorption (YJ). Treatments include no plant (C), plants only (H), and plants+2% HS (PH), which were evaluated in a pot containing respective soil. Biological indicators include microbial community analysis as well as soil enzyme activities of dehydrogenase, 𝛽-glucosidase, N-acetyl-𝛽-D-glucosaminidase (NAG), acid/alkaline phosphatase, arylsulfatase, and urease. Results showed an increase of enzyme activities in pot soils with plants and even greater in soils with plants+HS. The enzyme activities of DDC soil with plants (DDC_P) and with plants+HS (DDC_PH) increased 1.6 and 3.9 times on average, respectively than those in the control. The enzyme activities YJ soil with plants (YJ_P) and with plant+HS (YJ_PH) increased 1.8 and 3.8 times on average, respectively than those in the control. According to microbial community analysis, the relative abundance of nitrogen-fixing bacteria in DDC and YJ soil was increased from 1.5% to 7% and from 0 to 5%, respectively, after planting hairy vetch and sesban. This study showed that mixed planting of green manure crops with a supplement of humic substance is highly effective for the restoration of biological health indicators of reclaimed soils.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.340-340
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• 2017

Rice straw is very important to maintain fertility in agricultural soil with several aspects such as carbon and nitrogen cycles in Korea. Recently, concerning about climate change, carbon sequestration in agricultural land has become one of the most interesting and debating issues. Rice straw is most representative source of organic material produced in agricultural sectors. In order to evaluate changes of soil carbon treated by rice straw during cultivating rice in paddy field, we carried out to treat rice straw with 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$ at $50{\times}50{\times}20cm$ blocks made of wood board, and analyze contents of fulvic acid and humic acid form, and total carbon periodically. The experiment was conducted in 2013-2016, and sampled with interval in a month. The organic material was applied to treatment blocks in 2 weeks ago in rice transplanting of each year. Total carbon in beginning time is low as $7.9g\;kg^{-1}$. The contents of total carbon with treatments of rice straw after experiment are recorded as 8.7, 11.2, 9.5, 10.5, and $10.9g\;kg^{-1}$ applied by 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$, respectively. When trend lines were calculated on changes of soil carbon in periods of experiments, The trend equations of soil carbon changes with treatments of 0, 0.5, 1, 1.5, and $2.0ton\;ha^{-1}$ were Y=0.0015X+8.479, Y=0.073X+8.2577, Y=0.0503X+8.4477, Y=0.0822X+8.2103, and Y=0.082X+8.5736. These trends suggested several results. When rice straw was applied in cultivating paddy fields, most carbon in rice straw would be decomposed regardless the amount of rice straw in soil. We calculated sequestration rate of applied rice straw as about 0.1% per year during rice cultivation in paddy fields. It means that if farmer want to increase 1% soil organic matter by using application of rice straw returned after cultivation, famer should apply rice straw continuously for ten years. The change of soil carbon as fulvic acid, humic acid, and humane is showed that only content of carbon as mumine is increased significantly while fulvic acid and humic acid were changed in range of 10 to 30% among total carbon in soil. In conclusion, to sequestrate soil carbon with rice straw, it is important for rice straw to apply continuously every year. The amount of rice straw applied is not much effected to increase soil organic matter.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.3
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• pp.239-244
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• 1986

This study was conducted to investigate the characteristics of humic substances and the fractional distribution of organic nitrogen in Korean paddy soils. The results are obtained as follows: 1. The content of humus in soils used was 665-2680 mg/100g and the average contents of humic acid in normal paddy soils and in sandy paddy soils were 1436 mg/100g, 970 mg/100g respectively. 2. The humic acid diagrams classed by Kumada method belong to B type, P type and Rp type. 3. The content of Mineral - N to Total - N was 1.04-2.86% and the average contents of that in sandy paddy soils and in normal paddy soils were 1.72% and 1.75% respectively. 4. The fractionations of acid hydrolysable organic - N in sandy paddy soils were Amino acid - N (31.52%), Humin - N (20.63%), Amino sugar - N (18.70%), and Unknown - N (25.73%).

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.347-352
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• 1983

To characterize humus fractions in soil, visible, ultraviolet and infrared absorption spectra of humic acids in alkaline solutions and hymatomelanic acids in ethanol solutions extracted by Stevenson's method from paddy rice soils, peats, and volcanic ash soils were analyzed. The spectra patterns of both fractions in visible and ultraviolet ranges did not have any peak and the absorbance decreased as the wavelength increased. Visible and ultraviolet spectra of the solutions from all the peats, volcanic ash soils and paddy rice soil were very similar each other but absorbances were slowly declined in the order of volcanic ash soils, peats and mineral paddy soils. The infrared spectra of the two solutions appeared in a typical pattern, showing a few broad peaks. The main absorption bands were in the regions of $3400cm^{-1}$ (hydrogen bonded OH), near $2900cm^{-1}$ (aliphatic CH), $1720cm^{-1}$ (C=O of COOH, C=O of carbonyl), $1625cm^{-1}$ (aromatic C-C conjugated with C=O and/or COO-), $1400-1450cm^{-1}$ (CH stretch), $1200-1250cm^{-1}$ (CaO stretch of phenolic OH or OH-deformation of COOH) and $1050cm^{-1}$. The hymatomelanic acid fractions, however, had spectra that were characterized especially by very distinct absorption at $2900cm^{-1}$ and $1720cm^{-1}$, for aliphatic CH and carbonyl stretching vibration respectively in addition to the weaker bands for COO- or aromatic CH vibration at $1625cm^{-1}$, as compared to humic acid. No differences were noted in the general patterns of the spectograms of both fractions extracted. Analyses of the functional groups revealed little differences between peats and paddy soils, although total acidity and the content of carboxyl groups were decreased in the order of volcanic ash soils, peats and mineral paddy soils.