• Applied Biological Chemistry
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• v.20 no.3
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• pp.310-316
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• 1977

The adsorption of 2-Chloro-4-(ethylamino)-6-(isopropylamino)-s-trazine (Atrazine) and 2-Chloro-2' 6' diethyl-N(methoxymethyl)acetanilide(Alachlor) by 21 Korean surface soils is studied and discussed in relation to some properties of soils. 1. Adsorption of Atrazine was correlated posisively with content of clay and organic matter, but negatively with extractable potassium content and sand content. 2. Adsorption of Alachlor was correlated positively with organic matter, caly content and CEC, but negatively with sand content 3. Isothermal adsorpsion of Alachlor was confirmed to the Freundlich eguation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.3
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• pp.208-214
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• 1999

In order to determine if there is any physiographic preference for sedimentary organic matter preservation, two gravity cores were collected off Gampo, East Sea: one from continental shelf and the other from continental slope. Concentrations of porewater nutrients and total $CO_2$ were all higher in the continental shelf station, St. A, than the continental slope station, St. B. Meanwhile, concentrations of porewater sulfate decreased more rapidly at St. A than at St. B. Sedimentary organic carbon and nitrogen contents were lower and decreased more rapidly at St. A than at St. B. These data characters of porewater chemistry and sedimentary organic matter suggest that the organic matter is more actively decomposed at St. A than at St. B. At least over the study area, therefore, the sedimentary organic matter in the continental slope appears to be better preserved than that in the continental shelf.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.3
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• pp.33-37
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• 2018

In order to recycle sewage dredging soil, we analyzed particle size distribution and organic content of dredged sewage sediments. Based on this, it was determined that particles with relatively low organic content of 1.0 mm or more could be recycled as fine aggregate. Although it was inorganic at the size of 5 mm or more, it contained a number of foreign substances other than fine aggregate, which were needed to be removed with a sieve. Since there are volatile suspended solids between 1.0 and 5.0 mm size, they were removed by means of flotation. Fine aggregate was obtained from dredging soil by screening followed with flotation method, and the proportion of fine aggregate obtained in this study was around 38 %.

• Economic and Environmental Geology
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• v.36 no.1
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• pp.9-15
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• 2003

Two piston cores, obtained from the southwestern Ulleung Basin in East Sea, were analyzed to study the geochemical characteristics of the late Quaternary sediments and to detect any changes in sedimentary environment. The results show that the capacity of Total Organic Carbon is remarkably higher (average 1.8%) than that known from general open-sea. According to tephrochronology from known eruption ages, the sedimentation rates are high, ranging from 12.1 to 14.9 cm/kyr. The ratios of nitrogen and TOC (average 6.18-7.42) imply that the organic matter in the study area would be of oceanic origin. The correlation between sedimentation rates and sulfur contents suggests that the study area may be on the whole anoxic and somewhat high in primary productivity. During the Termination 1, inflows of organic matters were high. The sedimentary environments are characterized by rapid rates of sedimentation, and high anoxic values were compatible with accumulation of organic matters.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.707-716
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• 2005

Organic geochemical analyses including Rock-Eval pyrolysis, elemental analysis and stable carbon isotope analysis were performed to evaluate the characteristics of organic matter in the ODP Leg 127 Site 794A sediments and to understand paleoceanographic changes. Based on the TOC contents, C/N ratio, HI vs. OI, $\delta^{13}C_{org}$ and C/S ratio, results imply that dark layers containing a large amount of terrigenous organic matter were deposited under the suboxic/anoxic conditions, whereas the light layers containing largely marine organic matter were deposited under the oxic conditions. These results indicate that increasing surface-productivity by the input of a large amount of terrigenous organic matter from adjacent continent led to the deposition of dark layers during the interglacial highstands, whereas marine primary production and dilution caused by Kosa from the China desert area led to the deposition of light layers with the decreased to terrigenous organic matter during the glacial lowstands.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.130-135
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• 2002

Water-dispersible colloids are suspected to facilitate transport of contaminants to groundwater. This study evaluated some soil chemical properties in relation to the stability of colloids in soils of Jeju citrus orchards. Thirty surface soil samples were collected, and pH, organic matter content oxalate-extractable Al and Fe contents, and water-dispersible colloid content were measured. In soils of higher pH, water-dispersible colloid contents were higher. The stability of colloids was found to be significantly promoted at pH above 5$\sim$6. Since organic matter can act as a flocculant organic matter content significantly enhanced the colloid stability. In soils of less than 5% organic C, water-dispersible colloid content was expected to be significantly higher. In soils of higher oxalate-extractable Al and Fe contents, colloids remaining in suspension were lower. This indicated that amorphous oxides and hydroxides play important stabilizing roles in soil structure and can stabilize soil clay against dispersion. Therefore in soils of higher pH, lower organic matter, and lower amorphous clay minerals, the stability of water-dispersible colloids and the potential of colloid-mediated transport of organic chemicals to groundwater could be higher.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.592-599
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• 1996

The variations of asparagine and aspartic acid contents among the soybean varieties and in the different parts of soybean sprout after the different durations of storage were investigated. Asparagine and aspartic acid are known to have the detoxifying effects on acetaldehyde, which is highly toxic metabolites in the process of alcohol metabolism in the human body. The contents of asparagine and aspartic acid of beansprout showed continuosuly increasing trends along with the days to cultivation with a great varietal difference, especially in the roots. The duration of seed storage did not affect contents of asparagine content; the longer storage decreased aspartic acid content remarkably.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.329-333
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• 2006

Most of volcanic ash soils in South Korea are distributed in Jeju province which is an island placed on southern part of Korea and has steep slope mountain area. There are many soils containing high contents of organic matter (OM) derived from volcanic ash in Jejudo, also. Therefore, irrigation and drainage in volcanic ash soil different with general soil which has low OM content have to be applied with another management way, but studies searching appropriate methods for them are set on insufficient situation because the area of volcanic ash soil in South Korea is only 1.3% (130,000ha). This study was conducted for analysis of soil water content and irrigation quantity appropriate for crops cultivated in volcanic ash soil with high OM content. Although soils with different soil color have the same soil texture, soil water characteristics curve by soil color showed the difference of water retention capability by OM content. But, this characteristics classified with soil color could be unified by scaling technique with similitude analysis method which get dimensionless water content using a present water content, a residual water content and saturated water content (or water content at 10kPa). A relation of gravimetric soil water content (GSWC) and dimensionless water content by the results showed a form of power function. The dimensionless water content (DWC) express a relative saturation degree of present water content. This was also expressed by van Genuchten model which describe the relation between relative saturation degrees and matric potentials. These results on soil water characteristics curve (SWCC) of volcanic ash soil will be the basic of irrigation plan in area having high organic contents into soil.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.887-894
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• 2011

To evaluate the effects of abiotic factors of paddy fields on greenhouse gases (GHGs) emissions from rice paddy fields, $CH_4$ emission amounts were investigated from rice paddy fields by different soil organic matter contents, paddy types, and agricultural climatic zone in Yeongnam area during 3 years. $CH_4$ emission amounts according to soil organic matter contents in paddy field were conducted at having different contents of 5 soil organic matters fields (23.6, 28.7, 31.0, 34.5, and $38.0g\;kg^{-1}$), The highest $CH_4$ emission amount was recorded in the highest soil organic matters plot of $38.0g\;kg^{-1}$. High correlation coefficient (r=$0.963^{**}$) was obtained between $CH_4$ emissions from paddy fields and their soil organic matter contents. According to paddy field types, $CH_4$ emission amounts were investigated at 4 different paddy fields as wet paddy, sandy paddy, immature paddy, and mature paddy. The highest $CH_4$ emissions was recorded in wet paddy (100%) and followed as immature paddy 64.0%, mature paddy 46.8%, and sandy paddy 23.8%, respectively. For the effects of temperature on $CH_4$ emissions from paddy fields, 4 agricultural climatic zones were investigated, which were Yeongnam inland zone (YIZ), eastern coast of central zone (ECZ), plain area of Yeongnam inland mountainous zone (PMZ), and mountainous area of Yeongnam inland mountainous zone (MMZ). The order of $CH_4$ emission amounts from paddy fields by agricultural climatic zone were YIZ (100%) > ECZ (94.6%) > PMZ (91.6%) > MMZ (78.9%). The regression equation between $CH_4$ emission amounts from paddy fields and average air temperature of Jul. to Sep. of agricultural climatic zone was y = 389.7x-4,287 (x means average temperature of Jul. to Sep. of agricultural climatic zone, $R^2=0.906^*$)

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.351-356
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• 2006

A long-term experiment was initiated in 1979 at Experiment Farm of Honam Agricultural Research Institute, to investigate the effects of continued use of organic matter (rice straw and compost) along with different levels of nitrogen fertilizer in rice cultivation. The soils of experimental plots is classified as Jeonbug series developed on Fluvio-marine deposits. The application rates of rice straw and compost were 5 Mg/ha/year and 10 Mg/ha/per year, respectively. The fertilizer N application rates per season were 0, 100, 150, 200, and 250 kg/ha. In 2002, after 24 years of experiment, the effect of different treatments on soil pH, characteristics soil organic matter, soil N and P were investigated. The results of the study is summarized as following. The continue use of organic matter tended to lower the soil pH, to increase organic matter and available phosphate contents. The rice straw tended to lower soil pH more than compost, while the effect of compost was greater in increasing soil organic matter and available soil P then rice straw. The application of organic matter resulted in the increase in total organic N in the soil. Such effect was greater in compost application than in rice straw application. In organic N, greatest was amino acid-N, followed by unidentifiable organic N. The least was amino sugar-N. The application of organic matter with and without nitrogen fertilizer affected the in organic fractions of P, particularly Fe-P and Al-P. The application of rice straw tended to increase Ca-P.