• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.85-95
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• 1985

It has been tried to find effective biological control measures involved in nature of soil suppressiveness to fusarium wilt of cncumber caused by Fusarium oxysporum f. sp. cucumerinum Owen. Total 28 soil samples were obtained from Jinju, Haman, Namji, Milyang and Suncheon vinyl house area. The disease response of test soil was quantified in terms of DI50 value which caculated from log-probit transformation of diseases response curves. Soils designated 5 from Jinju, 7 from Suncheon, 22 from Namji were recognized as suppressive to fusarium wilt of cucumber. This suppressiveness was completely nullified after autoclave. The disease suppressiveness of tested soil did not indicate any consistency according to either chemical property or texture of soil. Conidial germination, induction and germination of chlamydospore were markedly inhibited in supprerssive soil compared to those in intermediate or conducive soils, however, mycelial lysis did not appear to have direct relationship with disease suppressiveness of given soil. Population density of fluorescent Pseudomonads and Bacillus spp. in the soil originated from different degree of suppressiveness were not different significantly but the number of lytic bacterial plaques measured by triple layer agar method was remarkably higher in suppressive soil than that in intermediate or conducive soil.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.139-144
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• 2008

A field experiment was conducted to investigate the influence of cultivars and compost on soil microbial activities and diversities in a red pepper-grown field. Compost was applied with 0, 30, and 60M/T $ha^{-1}$ in April and then red pepper seedlings of "Yong-go 4" and "Koeun" were transplanted in May 2007. Soil samples were collected in early August 2007. Measurement of microbial activities was based on a dehydrogenase assay and a fluorescein diacetate hydrolysis. Soil microbial community was characterized with Biolog $EcoPlate^{TM}$ and phospholipid fatty acid(PLFA). Red pepper cultivars did not differentiate the selected soil chemical and microbial properties. Soil pH and soil microbial community changed by amending the soil with 30 and 60 M/T $ha^{-1}$ of compost, and the soil organic matter and potassium content, and soil microbial activities increased in soils amended with 60 M/T $ha^{-1}$ of compost. Red pepper cultivar induced a little different soil chemical properties and microbial activity in soils amended with 60 M/T $ha^{-1}$ of compost even though significant differences were not found in those properties. In conclusion the effects of compost on soil chemical and microbial properties were much higher than red pepper cultivars in short-term period but the effects of red pepper cultivars should be investigated in long-term field test.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.98-102
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• 2009

Various physical properties of soils were investigated in the areas where organic farming had been practiced widely, for upland fields. The investigations were also conducted in the nearby fields under conventional to find out the influence of organic farming on the physical properties of soils. The investigated properties involved bulk density, hardness, shearing resistance, friction resistance, sinking depth of small rectangular board, water stable aggregates and the depth of soil available to plants. By and large, the practice of organic farming tended to improve all of the physical properties soils, investigated in upland soils. However, in case of water stable soil aggregates in upland soils, the reverse was previous data; in those soils water stable soil aggregates were less under organic farming. It was suspected that this might be due to intensive application of the organic materials with high C/N ratio like wood chips and wood bark. The contents of OM, Av. P2O5, and Ex. cations were higher in organic farming than those of nearby fields under conventional, due to heavy organic matter application. From the results, It could be concluded that soils under organic farming were looser and softer than those under conventional as shown by lower bulk density and hardness, but that the effect of organic farming on water stable aggregates were low.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.59-64
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• 1998

In order to elucidate the leaching behaviour of the herbicide bentazon in soil, soil columns(5cm ID ${\times}$ 34 cm L) were packed with three different soils up to 30 cm height, followed by the treatment of [$^{14}C$]bentazon, and rice plants(Oryza sativa L.) were grown for 9 weeks on these columns, with the columns without growing rice plants as the control for comparison. The amounts of $^{14}C$ activities percolated were about 92% of the originally applied $^{14}C$ irrespective of the physicochemical properties of the soils in the absence of rice plants, whereas $21{\sim}50%$ of the originally applied $^{14}C$ was percolated in the presence of rice plants, suggesting that the amounts of $^{14}C$ leached decreased remarkably in rice-cultivating soils. Bentazon leached faster in soil with higher pH and with lower organic matter content in the presence of growing rice plants. The amounts of $^{14}CO_{2}$ evolved from the soil columns were less than 0.2% of the originally applied $^{14}C$. Smaller amounts of $^{14}C$ were translocated into shoots via roots in soils with higher organic matter content. $^{14}C$ activities distributed into the aqueous phase of the leachate collected from the soil columns increased with leaching period and by rice cultivation, whereas the physico-chemical properties of soils did not exhibit any effect. The amounts of soil-bound residues increased remarkably by cultivating rice plants.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.462-462
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• 2018

국내 신규댐 건설에 있어, 침수토양의 용출에 의한 호내 수질영향에 대해서는 현재까지 정량화된 사례는 찾기 어려우며, 댐 담수 초기에 증가되는 오염원에 대한 정확한 조사자료의 부족으로 담수이후의 수질변화에 대한 정확한 예측이 어려운 실정이다. 따라서 외부 오염부하의 강우시 유입과 퇴적물로부터의 영양염용출 등의 내부 오염부하가 함께 고려된 수질예측기법의 적용이 필요하다. 수몰지 토양 및 호내로부터의 내부부하에 있어서는 퇴적물 내의 다량 존재하는 오염물이 재용출 되거나 퇴적물 내의 화학적 생물학적 반응이 하천 수질에 악영향을 미치게 된다. 대부분 수몰지토양에서 수층으로 용출되는 유기물의 양은 수층에서 퇴적물로 흡수 또는 침강 되는 것보다 많은 경우도 있으며, 오염된 수계에서는 내부 부하량이 과다할 경우 수질 개선을 어렵게 하는 요인이 되고 있다. 따라서 본 연구에서는 2016년 시험담수 예정지인 신규댐 수몰지를 대상으로 토양에 포함된 유기물이 자연상태에서 수체로 용출되는 특성을 분석하여 수질에 미치는 영향을 검토하고자 한다. 댐 수몰지의 토양 시료는 시험담수전 2016년 7월, 토지이용 유형별로 5개지점(논, 밭, 대지, 임야, 하천)에서 시료를 채집하여 총 36일간 용출실험을 실시하였으며, 수층내 용존산소 조건을 호기성 조건과 혐기성 조건으로 나누어 실험하였다. 수질분석은 COD, T-N, T-P, $PO_4-P$등 9개 항목에 대해 실험기간 중 13회 실시하였다. 토양별 점유면적 대비 일 용출량은(kg/day) COD 63 kg/day, T-N 93.6 kg/day, T-P 5.8 kg/day, $PO_4-P$ 4.6 kg/day 였으며, 수몰지 내 토지이용현황별 오염원 기여율은 임야, 밭, 하천, 논, 대지 순 이었다. 본 실험은 수몰지토양의 순수용출량만을 담수개시~36일간 측정한 결과로서 실제 저수지환경에서는 실험값보다 낮을 것으로 판단되며, 수중 수질환경 변화 및 퇴적물의 퇴적 등으로 인하여 원토양으로부터의 용출로 인한 수질에의 영향은 시간의 경과와 함께 변화 또는 감소될 것으로 예상된다. 따라서 본 실험결과는 담수초기의 영향으로 국한하여 해석하는 것이 바람직하며, 보다 장기적인 영향파악을 위해서는 담수 후의 퇴적물의 거동(퇴적현황) 파악 및 담수 후 퇴적물의 장기용출실험을 통한 용출량 검토가 필요하다.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.2
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• pp.99-105
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• 1976

After investigation of soil characteristics the properties of a reclaimed marine soil (Gupo series) distributed along the southern coastal areas of Korea are summarized as follows: 1. Gupo soils distributed in the southern Ria coastal area are derived from rolling to hilly materials and are poorly sorted with less influences of river fluvial action. These soils have high content of sand compared with the broad fluvio-marine soils in the western coastal areas. 2. The morphological features of the poorly drained Gupo soils are greyish brown sandy loam with a few yellowish mottles in the surface horizon and are grey sandy loam with a few gravel in the sub-strata. The ground water table remains around 10-30cm below the surface. These soils, recently reclaimed younger deposits, do not show any evidence of illuviation. 3. The "n" value (about 0.8) of the Gupo soils indicates physically unripened soils. 4. pH value of these soils shows more than 8.0 throughout the profile. Organic matter contents are extremely low (around 0.5%) except 1.2 percent in the surface horizon. C.E.C. ranges from 7 to 9m.e/100g which is lower than average in the country. The ratios of extractable cations such as Ca, Mg, Na and K of the surface horizon are 20:7:4:1. Base saturation is more than 60%. Available phosphate content is very low that is less than 25 ppm. Electric conductivity of the soils at $25^{\circ}C$ ranges 7 to 12 mmhos/cm and increased with depth. 5. According to classification of soil based on physical ripening, the Gupo soils can be classified into "Unripe soils with half-ripe sub-soils". The soils could be classified into "Hydric Haplaquents" in the original of the 7th Approximation (1960), but into "Typic Haplaqents in the supplement of 7th approximation which the physical ripening condition is not clearly expressed. Soil Taxonomy, apparently the final version of the 7th approximation, defines the soils as "Haplic Hydraquents" that clearly show the condition of physical ripening as well as other properties. Other several classification systems applied do not describe physical ripening condition of the soils.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.205-210
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• 2010

This study was conducted to investigate the effect of the mixed ratio of the soil amendments, peat, humate, peatmoss and zeolite, on the soil physicochemical properties. The mixed ratios of soil amendments were 0%, 3%, 5%, 7% and 10% (v/v) incorporated with sand which met to the USGA (United State of Golf Association) recommendation. It was measured pH, EC and CEC as a chemical properties. Porosity, capillary porosity, air-filled porosity, bulk density and hydraulic conductivity were also measured to analyze the changes of physical properties. Chemical properties were significantly different by mixture ratios of peat, humate, peatmoss and zeolite. When the results were applied to the USGA standard of the soil physical properties, the optimum mixture ratios of peat, humate and peatmoss were 5%, 3% and 7%, respectively. Air-filled porosity was factor involved in soil physical properties by blending with soil amendments and it was affected on volume of porosity and hydraulic conductivity. To analyze the corelation of mixture ratio versus to physical characters, the ratio of peat and peatmoss was significantly related to capillary porosity and hydraulic conductivity (P<0.05), that of humate hydraulic conductivity (P<0.01), and that of zeolite air-filled porosity and volume of porosity (P<0.05). These results could be used as a basic data for construction USGA sand green.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.123-131
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• 1999

To get the basic information for the improvement of the optimum levels of upland soil fertility and fertilizer application, the soil samples in two hundred fifteen site were collected from the major condiment vegetable cultivation areas such as red pepper, garlic and onion fields. Physico-chemical properties of the soil samples were investigated. Soil texture distribution of soil samples in red pepper, garlic and onion cultivation areas was in order of loam (L), sandy loam (SL), silt loam (SiL) and clay loam (CL) (35.4, 31.6, 14.9 and 7.0%, respectively). The average pH of soil in garlic and onion cultivation areas were over pH 6.0, whereas in red pepper was under pH 5.5. The frequency distribution of soil pH in total sampling sites were 58.7% in under pH 6.0 and 21.4% in below pH 5.0, in contrast to 10.3% in over pH 7.0. The organic matter contents were in the range of $20{\sim}30g\;kg^{-1}$, and the onion field soils was a little higher than those in red pepper or garlic. The available phosphate contents were in the range of $719{\sim}746mg\;kg^{-1}$ and were not different among in red pepper, garlic and onion. The frequency distribution of available phosphate in total sampling sites were found 62.8% of above $600mg\;kg^{-1}$, which was over the standard level for upland soil improvement, and then 22.3% was exceeded $1,000mg\;kg^{-1}$, especially. In the exchangeable cations, the K and Ca contents in garlic (1.27 and $9.11cmol\;kg^{-1}$) and onion (1.20 and $8.39cmol\;kg^{-1}$) were higher than in red pepper (0.96 and $5.87cmol\;kg^{-1}$), respectively. The Mg contents in garlic field soils ($2.17cmol\;kg^{-1}$) were higher than those in red pepper and onion (1.51 and $1.80cmol\;kg^{-1}$). This exchangeable K, Ca and Mg contents were higher than the standard level for upland soil improvement. The contents of microelement were ranged in $54.3{\sim}60.1mg\;kg^{-1}$ for Fe, $31.3{\sim}42.3mg\;kg^{-1}$ for Mn, $1.7{\sim}2.3mg\;kg^{-1}$ for Cu and $4.8{\sim}5.5mg\;kg^{-1}$ for Zn, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.275-281
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• 1996

The objective of the study was to investigate the effects of water treatment sludge (WTS) on the growth of soybean and carrot, and uptake of some inorganic components in the plants. WTS was incorporated to field at the rates of 0, 1, 3, and 5 tons per 10a on the basis of dry weight. With the application of the sludge, OM and CEC in the soil increased slightly while the concentration of available phosphorous decreased. And heavy metals, including Pb, Cd, Cr, As and Hg, were not detected at the harvest stage in crops. With an increase in the application of the sludge, the concentration of phosphorous in the seed of soybean and the root of carrot tended to be decreased. There seems no correlation between rate of application of the sludge and uptake of Al in the plants. The yield of soybean was the highest when applied to one ton sludge and the yield on carrot increased with an increase in rate of applied sludge. Also, the concentration of carotene increased with an increased application of the sludge. But, application of WTS showed to deteriorate the visual quality with an irregularity of carrot's surface. This results indicate that application of WTS will be give a positive and negative effects on soil and crops.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.26-37
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• 1992

Fifty-five field experiments were conducted in order to find out some useful indices for the prediction of N-supplying capability(NSC) of soils under cultivation of corn in Pennsylvania over 3 years from 1986. Contents of $NO_3-N$, absorbance at 200 nm of the extract from soil with 0.01M $NaHCO_3$ were identified to be used as indices before planting. Methods for the estimation of organic nitrogen available later in the growing season(KCLA-N, PBBA-N, UV260 nm absorbance of $NaHCO_3$ extract) were not to be used as good indices individually, but when those are combined together with inorganic $NO_3-N$ showed a highly significant correlationship with the NSC. The year of an even distribution of rainfall, 1987, gave the highest significant correlationship between NSC and the indices. For soils of the same texture with slightly different physical properties, combined indices obtained from physico-chemical factors improved the degree of predictability when the grades of soil slope, depth of Ap were considered at the same time. More futher researches such as this need to be done before any conclusive result can be drawn.