• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.50-57
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• 2020

BACKGROUND: Biochar is used in various environmental fields, such as water quality and soil restoration, and affects soil fertility and nutrient cycling. Also, when crops are grown on biochar-applied soil, their characteristics may be affected. Biochar is used especially with commercial vegetable seedlings. METHODS AND RESULTS: The objective of this study was to determine the effects of biochar content in seeding mixes on early growth of lettuce (Lactuca sativa L.), Chinese cabbage (Brassica rapa L.), and red pepper (Capsicum annuum L.). Treatments consisted of a control (0: 10, ratio of biochar to seeding mixes (w/w)), 1: 9 (biochar 10%), 3: 7 (biochar 30%), 5: 5 (biochar 50%), and 7: 3 (biochar 70%). The biochar was made from risk husk and had a C/N ratio of 104. As the mixing ratio of biochar increased, pH increased whereas EC and nitrogen content decreased. The highest phosphorus content was with the treatment of 30% biochar, while there were significant increases in the weight of lettuce seedlings and concentrations of T-N, P₂O₅, K₂O, MgO, and Na with the treatments of 30% and 50% biochar. Although the weight of Chinese cabbage seedlings increased with the treatment of 10% biochar, the increase was not statistically significant. Also, there was an increase in the weight of red pepper seedlings with the treatment of 30% biochar, but the increase was not statistically significant. With increases in the biochar mixing ratio, the K₂O concentration of red pepper seedlings increased, but the concentrations of P₂O₅, CaO, MgO, and Na decreased. It was believed that this was because of absorption inhibition by calcium-phosphate formation in the seeding mixes owing to increased pH. CONCLUSION: In conclusion, adding biochar to seeding mixes is considered to be an important mean for growing healthy vegetable seedlings. More field experiments are needed to verify the effect of biochar on vegetable crop growth over the entire growing season.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.265-270
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• 2008

This study examined the effects of treating green tea leaves with ozonated water by evaluating pesticide residue levels and catechin content. The pesticide residue levels of tea leaves treated with carbendazim, captain, diazinon, fenthim, dichlorvos, and chlorpyrifos ranged from 43.2 to 48.2 ppm. For leaves treated by soaking or watering with tap water, or with 0.25 ppm of ozone water for 30 min. Pesticide residue levels were reduced by 24.0-30.2%, 30.3-33.6%, 52.4-70.5%, and 65.5-80.2%, respectively. No major differences in catechin content were observed in the leaves according to the soaking and rinsing treatments using ozonated or tap water.

• Korean Journal of Medicinal Crop Science
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• v.22 no.5
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• pp.363-368
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• 2014

This study was conducted to find out the optimum composition of nursery soil for raising seedling of ginseng (Panax ginseng C. A. Meyer). Total 9 kinds of raw materials were used such as peat-moss, perlite, leaf mould, rice bran, gull's guano, castor-oil plant bark, palm bark, cow manure and chicken manure for optimum composition of nursery soil in ginseng. Occurrence of damping-off in ginseng was lowered about 50% in nursery soil type 1, 2 and 4 than in other types nursery soil in June, and occurrence rate of rusty root also lowest in nursery soil type 1. As the salinity of nursery soil increased, so did the occurrence of physiological disorder in ginseng seedling. The cause of salinity increasing in nursery soil has closely relation to $NO_3-N$, $P_2O_5$ and $Na^+$ content. Plant height, root length, diameter and weight were longer and heavier in nursery soil type 1 (mixing ratio of peat-moss, perlite and leaf mould was 50 : 20 : 30 based in volume) than in other types of nursery soil. So nursery soil type 1 was selected for raising seedling of ginseng. pH and electric conductivity (EC) of selected nursery soil type 1 was 5.55 and 0.13 dS/m. Contents of $NO_3-N$ and $P_2O_5$ were 21.0 and 40.0 mg/L, and $K^+$ 0.36, $Ca^{2+}$ 3.38, $Mg^{2+}$ 2.01 and $Na^+$ $0.09cmol^+/L$, respectively.

• Research in Plant Disease
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• v.14 no.3
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• pp.176-181
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• 2008

This experiment was conducted to find the causes of ineffective seed disinfection methods such as rice seeds soaking in hot water and prochloraz EC solution when the rice seeds were severely infected by Bakanae disease. In case of rice seeds collected from severely diseased field by Bakanae disease, the pathogen as the forms of spores and mycelium were infected in plumule and inner and outer integument of embryo, aleurone layer, and pericarp layer. When the rice seeds were soaked in hot water, the appearances of spores and hypha on the outer pericarp layer were severely disordered, however those of inner region of outer integument and aleurone layer were shown normal. The membrane of hypha on the outer pericarp layer was destroyed within 24 hours, while some spores were healthy and germinated 7 days after soaking, when the rice seeds soaked 24 hours in 125 ppm prochloraz solution at $30^{\circ}C$. These results indicated that the seed disinfection methods were ineffective on the Bakanae disease severely infected rice seed because the hot water did not transmit the pericarp layer of rice seed and also prochloraz solution did not effectively destroy the spore of pathogen.

• Journal of the Korean Society of Groundwater Environment
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• v.3 no.1
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• pp.27-36
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• 1996

The Nanji landfill is one of the biggest uncontrolled landfill in terms of its size and scale in the world. Because the landfill was constructed on the very vulnerable alluvial deposit installing no pollution control systems such as bottom liner and leachate collection systems, it has caused a serious adverse effect to near-by groundwater and surface water systems. A through remedial investigation comprising plume detection and site-characterization was performed to design the remedial measure. As a part the investigation, comprehensive water quality study was conducted, using ten existing observation wells and one bundle type monitoring well, to determine the contaminant indicators for the plume delineation and to define the vertical and horizontal variation of specific contaminants via distances from the landfill. The results clearly shows that EC and temperature are a good pollution indicators and the vertical concentrations of specific contaminants measured in the fully screened wells are 20 to 90% more than those measured at the same depth in bundle type well which is located just 2 m apart. This paper presents a cost effective monitoring and sampling method to define the contaminant plume and obtain a basic data for leachate control measures.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.438-441
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• 2003

남해 동부 연안 지역 지하수의 해수 침투 영향을 광역적으로 파악하기 위하여, 202개소의 지하수 시료를 채취하고 수리지구화학적 연구를 수행하였다. 전체 시료 중 14.4%가 500 $\mu\textrm{m}$/cm을 초과하는 높은 EC값을 나타내어 해수 영향을 시사해 주었다. 해수 영향 판단의 또 다른 파라메터로 사용되는 CI/HCO$_3$ 몰비는 전체 시료의 23.3%가 1.3 이상의 값을 나타내었다. 한편, 대표적으로 해수침투 영향 및 인위적 오염의 영향을 각각 반영하는 것으로 알려진 Cl과 NO$_3$의 농도에 관한 누적도수분포도를 작성하여 배경수질군과 오염영향군을 구분짓는 배경치(background concentration)를 구한 결과, 각각 Cl = 22.3 mg/1 및 NO$_3$= 23.1 mg/l로 나타났다. 이 두 파라메터의 농도 분포를 기준으로 하여 채취된 지하수 시료를 크게 4개의 그룹으로 나눌 수 있었다. 그 결과, 자연적 또는 인위적 기원의 오염이 배제된 그룹 1은 전체 시료의 31%, 자연적 오염(해수 영향)을 반영하는 그룹 2는 전체의 24%, 인위적 오염의 영향을 반영하는 그룹 3은 전체의 9%, 해수 영향 및 인위적 오염을 동시에 반영하는 그룹4는 전체의 36%로 나타났다. 또한 그룹2와 그룹4는 대부분 Na-Cl유형으로 진화하는 Ca-Cl유형을 나타내었다. 따라서, 여러 지구화학 방법에 의한 해수 영향 판단 결과는 서로 잘 일치하고 있음을 알 수 있다. 결국, 지구화학적 파라메터를 종합적으로 활용함으로써, 연안 지역 해수침투의 효과적인 파악은 물론 예측 및 방지, 복구에 효과적으로 사용될 수 있을 것으로 판단된다.으로 토양에서 유동 가능성이 있는 중금속만을 추출하였다. 분석실험은 토양의 Cd2+ 와 Pb2+를 대상으로 행하여졌으며, 여러 토양에서 추출 분석한 결과를 EDTA분석결과와 비교하였다. 실험결과, 중금속은 매우 신속하게 고분자 자성체와 결합하였고, 그 후 자성체를 외부 자장으로 모은 후 산으로 용해시키고, 결합된 중금속은 Graphite furnace AAS로 분석함으로써 빠르고 효율적으로 분석실험을 수행할 수 있음을 알 수 있었다. 한편, 실험에서 나타난 수치들을 비교 검토한 결과 토양 분석시 sandy soil에서는 자성체를 이용한 분석이 EDTA에 의한 방법보다 더 높은 추출도를 보인 반면, silt 함량이 많은 토양의 경우에서 EDTA분석에서 더 높은 중금속 추출도를 보였다.s 중에서 490nm와 555nm의 복합밴드를 포함하는 OC2 알고리즘(ocean color chlorophyll 2 algorithm)을 사용하는 것이 OC2 series 및 OC4 알고리즘보다 좋은 추정 값을 도출할 수 있을 것으로 기대된다.환경에서는 5일에서 7월에 주로 이 충체의 유충이 발육되고 전파되는 것으로 추측되었다.러 가지 방법들을 적극 적용하여 금후 검토해볼 필요가 있을 것이다.잡은 전혀 삭과가 형성되지 않았다. 이 결과는 종간 교잡종을 자방친으로 하고 그 자방친의 화분친을 사용할 때만 교잡이 이루어지고 있음을 나타내고 있다. 따라서 여교잡을 통한 종간잡종 품종육성 활용방안을 금후 적극 확대 검토해야 할 것이다하였다.함을 보이고 있다.X> , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.463-471
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• 2000

A pot experiment was carried out to find out the effects of the sludge application on corn and Chinese cabbage growth and changes in soil chemical properties with sludges collected from 4 plants at 0, 12.5, 25, 50, and $100Mg\;ha^{-1}$ levels and chemical fertilizer. With the corn experiment, the pot where sludge and chemical fertilizers were treated together, greater amount of sludge resulted in initial growth inhibition. In general, higher sludge treatment rates resulted in better growth in the end, whereas initial growth was inhibited due to high the electrical conductivity of saturated extracts(ECe) for the Chinese cabbage. However, the highest yield among sludge treatments was lower than the yield with chemical fertilizers. While the treatments resulted in chemical changes in soil showing differences of cation exchange capacity, organic matter contents, and nitrogen contents, hardly any changes were detected before and after crops were grown. Inorganic nutrients such as Na, K, Ca and Mg showed similar changes. The ECe in soil saturation extract decreased after crops were grown. The more sludge was treated, the greater was the decrease. The differences of ECe in the soil saturation extract with varying degrees of treatment were also reduced after crops were grown. Available phosphorus content increased during growth. Due to the low nitrogen content in sludge, when nitrogen becomes the determining factor for the amount of sludge treatment, phosphorus buildup resulted from continued application of sludge could be raised. Therefore, it is advisable to use phosphorus, not nitrogen content, in determining the amount of sludge treatment and chemical fertilizer as supplementary sources for nitrogen.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.242-247
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• 1997

This study was conducted to investigate the combined effects of oyster shell, fly ash and gypsum on rice yield and quality. The four treatments of soil amelioration were oyster shell 4, fly ash 80, fly ash 56 + gypsum 24 and oyster shell 0.8 + fly ash 40 + gypsum 24 ton/ha. Rice yield were in the order of oyster shell, fly ash and control plats. The pH, EC values and OM, Ca, $SO_4$, moisture contents of the top-soil after rice harvesting in soil amelioration treatments were increased, while Mg, Na, Fe, Zn and Al were decreased than those of control. Rice quality was the best in the fly ash plat due to lower T-N and higher Mg/K ratio.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.206-213
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• 2008

We observed the physical and chemical properties of a soil on pine mushroom picking areas where were located in the most upper and lower parts showing a comparative climatic characteristics in Korea. The slope gradients within the investigation areas which were divided into 100 quadrates of $1m^2$ ranged from $5.7{\sim}8.6{\beta}$ to $24{\sim}22.7{\beta}$ (left to right) and $4.5{\sim}6.8{\beta}$ to $13.5{\sim}17.8{\beta}$ (top to bottom) for Ponghwa and Gansung, respectively. The amount of clay and thickness of organic matter were significantly decreased with increasing slope gradient, resulting in decrease of the soil moisture content around a fairly ring-colony of Tricholoma matsutake which was observed under the relatively thicker organic matter layer beyond 3 cm depth. Soil pHswere weak acid and average EC was $0.44dS\;m^{-1}$ in both areas. The cations were in the order of Fe K > Na > Mg > Ca and Fe > K > Na > Ca > Mg for the upper(Gansung) and the lower (Ponghwa) part. And the amount of Fe was approximately $80dS\;m^{-1}$ or greater in the pine mushroom picking soil. From this, we could assume that the growth of the pine mushroom was closely related not only with iron but also soil moisture content.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.194-204
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• 2015

Six study sites in Gumi, Goryeong in Gyeongbuk province and Naju in Jeonnam province were selected to investigate soil properties of poorly drained horizons in paddy soils. The horizons were re-established layers which were parent material layers originated from fluvial deposits. Topsoil layers were differentiated from piled parent materials while soil structure of the topsoil layer was massive with striated microstructure. Compaction at soil re-establishment and a lack of structure and aggregate development in these soils may cause the limitation of vertical water movement and result in poorly drained horizons. Soil samples were taken from paddy fields with top soils of sandy loam, silt loam and silty clay loam and re-established soils of coarse and fine texture. The samples were taken from each horizon for the analyses of soil chemical and mineral properties. Soils with re-established soils of coarse texture had greater amounts of sands from top soil texture distributions, while soils with fine texture had greater amounts of silts. Chemical properties of top soils were analyzed from rice cultivated soils at the time of re-establishments and one year after the re-establishments. The coarse texture of the re-established horizons decreased in EC values from 0.23 to $0.11(dS\;m^{-1})$, available phosphate values from 112 to $54(mg\;kg^{-1})$, and exchangeable Ca values from 6.6 to $4.9(cmol_c\;kg^{-1})$. On the other hand, soils with fine texture showed decrease only in pH and exchangeable Ca values. Especially, organic matter and available phosphate contents showed heterogeneous distributions from each horizon. This result may be caused by mixture of plough layer and subsurface layer during and consolidation. Hydraulic conductivity values were low at the boundaries of top soil and parent material layers except SL/coarse soil. Soil microstructure was massive structure without soil clods or pores and showed striated structure. Therefore, re-established paddy fields with fluvial deposits as parent material layers showed limited vertical movements of soil water because of occurrence of compacted layers and less-development of soil clods and aggregates.