• Korean Journal of Soil Science and Fertilizer
• /
• v.11 no.3
• /
• pp.127-144
• /
• 1979

Recent trend in the studies on the forming processes, chemical characteristics and chemical structure of humic substances with some discussions are reviewed and some arguments for the elucidation of the chemical structure of humic substances are summarized.

• Journal of the Mineralogical Society of Korea
• /
• v.29 no.2
• /
• pp.35-45
• /
• 2016

Clays, which are abundant in nature and eco-friendly, have been utilized throughout human history due to their characteristic physicochemical properties. Recently, a variety of clays such as montmorillonite, kaolinite, sepiolite and layered double hydroxide with or without chemical modification have been extensively studied for potential application in industries. Clays that possess a large specific surface area, high aspect ratio, nanometer sized layer thickness and controllable surface charge could be utilized as polymer fillers after appropriate chemical modifications. These modified clays can improve mechanical and gas barrier properties of polymer materials but also provide sustained antibacterial activity to polymer films. Furthermore, engineered clays can be utilized as scavengers for chemical or biological pollutants in water or soil, because they have desirable adsorption properties and chemical specificity. In this review, we are going to introduce recent researches on engineered clays for potential applications in future industries such as food packaging and environmental remediation.

• Korean journal of applied entomology
• /
• v.21 no.2 s.51
• /
• pp.68-72
• /
• 1982

Soil environmental factors, affecting population of Fusarium spp. and root rot of Panax ginseng were investigated in the ginseng cultivated soil. In the 2-year-old ginseng cultivated soil, the number of Fusarium spp. and the amount of available phosphorus were significantly decreased as clay content was increased in the soil. Also the missing rate of ginseng plants and the amount of nitrate nitrogen appears to be decreased as clay content was increased in the soil, although, it was not statistically significant. In the 6-year-old ginseng cultivated soil, there was highly significant negative correlation(r=-0.3976, p=0.01) between the number of Fusarium spp. and that of Streptomyces spp. Relationship between root rot and the amount of available phosphorus was significantly positive (r=0.3162, p=0.05), however, there was no correlation between the two factors within same soil torture.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2006.04a
• /
• pp.234-237
• /
• 2006

방부 목재는 일반 목재에 비해 사용 수명이 20-40년 정도 길기 때문에 사용이 점차 증가하고 있다 국내에서 가장 널리 사용되는 방부제는 chromate copper arsenate(CCA)이다 CCA 성분인 구리, 크롬 및 비소는 생태계 및 인체에 대한 위해성 때문에 많은 나라에서 처리 목재의 사용을 금지하거나 제한하고 있는 실정인 반면에, 국내에서의 사용은 늘어만 가고 있는 실정이다. 이 연구에서는 방부 목재를 사용하여 지은 3년 된 통나무집 한 곳과 8년 된 통나무집 두 곳에 인접한 토양시료를 채취, 분석하여 방부 목재 사용으로 인한 토양 오염도를 평가하였다. 건물에 인접한 지점부터 수평 방향으로 25cm 간격으로 100cm까지 5개의 표토 시료를 채취하였다. 또한 배경 농도를 알아보기 위해서 건물에서 조금 떨어진 곳에서 토양시료를 2개 채취하였다. 토양시료는 입도, 전기전도도, pH, 유기물 함량 등의 물리 화학적 성질에 대해 분석하였으며, CCA성분은 microwave oven을 이용하여 추출한 후 분석하였다. 0cm에서 CCA성분은 배경 농도보다. 높게 나타났다. 용출양은 3년 된 통나무집의 경우 크롬(67.2mg/kg)>구리(20.3mg/kg)>비소(4.14mg/kg)의 순으로 측정되었으며, 8년 된 통나무집의 경우 크롬(36.6mg/kg)>구리(21.3mg/kg)>비소(1.93mg/kg)의 순으로 측정되었다. 구리를 제외하고 크롬과 비소의 경우 3년 된 통나무집에서 많이 용출되는 것을 알 수 있었다. 3년 된 통나무집의 구리와 크롬은 100cm농도가 배경농도보다. 높게 나타났으며, 비소의 경우는 100cm농도가 배경농도보다. 낮게 나타났다. 이는 구리와 크롬이 100cm이상으로 이동을 한다는 것을 알려주며, 8년 된 통나무집의 경우는 크롬과 비소가 100cm이상으로 이동한다는 것을 알 수 있었다. 이 연구를 통해 CCA로 처리된 방부목재에서는 CCA성분이 용출되는 것을 알 수 있었으며, 크롬과 비소의 경우는 초기에 많이 용출되고, 구리의 경우는 꾸준히 용출되는 것을 알 수 있었다. 3년 된 통나무집이 8년 된 통나무집보다. 용출양이 더 컸으며, 이는 CCA성분이 초기에 많이 용출된다는 것을 의미한다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.3
• /
• pp.160-166
• /
• 2009

We estimated site productivity for unstocked land based on the relationship between site index (i.e., average height of dominant trees at fixed age) and soil physico-chemical properties of Pinus densiflora stands. Site index relates to a direct method of determining a tree's response to a specific environment such as forest soil and climate conditions. We selected 78 sites in 22 P. densiflora stands of central temperate forest zone, and sampled soils for physicochemical analyzing. And 13 properties of soils were statistically treated by stepwise regression. In the degree of contribution of the variables to site index, the highly effective variables in A horizon were OM, clay content, sand content, available $P_2O_5$, and Exch. $Ca^{{+}{+}}$ inorder, and in B horizon T.N., O.M., Soil pH, cation exchange capacity(C.E.C.), and sand content in order. In both A and B horizon of the soil for P. densiflora stands, the variables commonly contributed to the site index were sand content and OM. These results may be useful to provide not only important criteria for establishment of Pinus densiflora stand sespecially in unstocked land but also aguidance for reforestation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.11 no.3
• /
• pp.161-174
• /
• 1979

A review was made on the effect of organic matter application on the chemical characteristics of soils such as pH, solubilities of minerals, and cation exchange capacity mainly at flooded rice soils. The review can be summarized as follows: 1. Application of organic material such as rice straw and compost in flooded rice soil leads to a temporary lowering of soil pH at the earlier stage of soil reduction, due to the production of various organic acids and carbonic acid. This temporary lowered pH is replaced with the production of alkaline substances such as ammonia as the reduction of soil proceeds. 2. Incorporation of organic materials intensifies the ferrous iron, dissolving various minerals, virtually to the increase in electrical conductivity of soils. 3. Organic materials also play an important role in dissolving soil minerals through the production of various chelating agents. 4. Application of soil organic matter significantly increases cation exchange capacity of soils. 5. Continuous application of rice straw or compost leads to the increase in soil organic matter content to some extent, up to the level of equilibrium. In soils low in organic matter the equilibrium level is attained with five years continuous application of compost. 6. The manner of chemical fertilizer application influences the accumulation of organic matter applied in soils. Low levels of fertilization lowers the accumulation while high levels of fertilization accerelates the accumulation.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.31 no.2
• /
• pp.159-166
• /
• 2011

This experiment was carried out to investigate the effect of application of swine slurry (SS) and slurry composting-biofilteration liquid fertilizer (SCB) on productivity of sorghum${\times}$sorghum hybrid (SSH) and soil environment in reclaimed land of Sukmoon in Korea. Dry matter (DM) yields of SSH in the treatments of SS and chemical fertilizer (CF) were higher than those of in SCB treatment in reclaimed land, but DM yields in SS and CF did not show a significant difference as compared to SCB. Nutritive values of SSH were not different among CF, SS and SCB. In soil samples collected at the end of the experiment, the concentration of organic matter was significantly increased by SS and SCB as compare to that at the beginning of the experiment (P<0.05), whereas the concentration of total nitrogen was not affected by SS and SCB. To investigate the moisture content of soil, the soils were collected from three layers; surface (0~5 cm), intermediate (10~15 cm), and deep (20~25 cm) layer. The moisture contents of soils increased according to the soil depth and the soil moisture was immediately affected by the amount of rainfall. Therefore, we suggest that the cultivation of SSH using SS in reclaimed land is possible and that additional nitrogen fertilizer was surely applied in case of application of SCB to cultivate SSH.

• Korean Journal of Soil Science and Fertilizer
• /
• v.4 no.2
• /
• pp.187-192
• /
• 1971

This paper deals mainly with the genesis and classification of the Jeonnam series. These soils have brown to dark brown silt loam and silty clay loam A horizon(strong brown or reddish brown where eroded). Argillic B horizons are dominantly red or yellowish red silty clay loam to silty clay with moderately developed subangular blocky structure and with thin clay cutans on the ped faces. The C horizons are strongly and very deeply weathered strong brown, yellowish brown, pale brown and reddish yellow silty clay loam and sandy loam granitic saprolite. Content of clay increases with depth to a maximum between 100cm. Percolating water seems to be responsible for transportation and oriented deposition of clay. Chemically, soil reaction is strongly acid to medium acid throughout the profile. The content of organic matter is 1 to 2 percent, and decreases regularly with depth. Base saturation is low, based on amount of extractable cations. Characterisltically the Jeonnam series are similar to Red-Yellow Podzolic soils of the United States and are similar to Red-Yellow soils of the Japan. In the writer's opinion the Jeonnam soils are classified as Red Yellow soils. According to USDA 7th approximation, this soil can be classified as Typic Hapludults and in the FAO/UNESCO World Soil Map as Helvic Acrisols.

• Applied Biological Chemistry
• /
• v.29 no.1
• /
• pp.62-72
• /
• 1986

At present, the definition and chemical analysis method of available soil phosphorus for plants have not been standardized because of the complexity of crop and soil characteristics in Korea and many analysis methods have been suggested with different extraction conditions. Suitable analytical method of available soil P should be established by the trial of various methods based on crop nutrition and soil conditions. To establish the most suitable analysis method of available soiIP, a pot experiment with young maize was conducted over 44 different upland soils collected over the land of Korea. The amount of uptaken P by the plant was determined by ten different chemical methods for the available soil P. The results obtained were as follows: 1. Total phosphorus content in the sample soils ranged ranged $533{\sim}4917\;ppm$, and showed significant positive correlation with the content of organic matter. 2. The P content was relatively low in the acid sulfate soil and very high in the volcanic ash soil although both types of soil contained high level of orgic matter. 3. The amount of extractable P determined by ten different methods were varied more or less, and the ratios of the extractable P to the total soil P were in the range of $1{\sim}48%$. 4. The relative values to the amount of extractable soil P by different methods were in the order of $H_2O(5\;min.)\;1.0\;<\;H_2O(60min.)\;2.27\;<\;NH_4HCO_3\;5.57\;<\;NaHCO_3\;7.42\;<\;Double\;lactate\;9.71\;<\;Bray\;No.1\;12.53\;<\;Lancaster\;17.63\;<\;Nelson\;25.96\;<\;AcOH\;27.6\;<\;CAL-method\;50.27$ 5. The amount of extractable P determined by all of applied methods was very low in acid sulfate soil, volcanic ash soil and coarse textured soil. 6. Soil pH and total soil P generally showed significant positive correlation with the chemically extracted P, and soil organic matter was negatively correlated with the determined by Nelson-and CAL-method. Olsen method which showed significant correlation with exchangeable calcium seemed to be recommendable for calcareous soils. 7. Total amount of uptaken P by Young maize through continuos twice cropping was 4.05% of total soil P in average, and the uptake in the second cropping was twice as much as that of the first cropping. 8. Three determination methods, i.e. Soltanpour-, Double lactate and Bray No. 1-method seemed to be more suitable than Lancaster method which is widely practiced at present in Korea. However, further study should be carried out with other crops and soils to most adequate chemical method for determination of available soil P.

• Korean Journal of Soil Science and Fertilizer
• /
• v.31 no.2
• /
• pp.120-127
• /
• 1998

This study was performed to produce basic data for developing prediction techniques of desalinization through analyzing soil properties of reclaimed tidal lands, using soil samples collected in 11 units of tidal land reclamation projects. The average apparent specific gravity (bulk density), real specific gravity (particle density), porosity, and saturation percentage were measured to be 1.33, 2.64, 49.6%, and 56.3%, respectively. It was estimated that the soil texture class of reclaimed tidal lands would be silt or silt loam. The electrical conductivity and exchangeable sodium percentage were estimated to be $20{\sim}40dS\;m^{-1}$ and 30~50% in the beginning of tidal land reclamation, and the value of pH was measured to be 6.5~7.9. In conclusion, the soil properties of reclaimed tidal lands could be descrived to be saline-sodic soils with the high electrical conductivity and exchangeable sodium percentage.