• Horticultural Science & Technology
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• v.34 no.6
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• pp.807-817
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• 2016

Many onion growers and researchers assert that differences in soil type, agricultural practices, weather, and duration of prolonged onion cultivation in a particular field could affect onion bulb quality. This study evaluates the bulb quality of onions grown in different regions and determines the correlations between bulb characteristics and postharvest loss during cold and ambient storage. Soil and onion bulbs were collected from fields in six onion growing regions in Korea, during the growing season of 2011-2012. The fresh weight, dry matter content, and carbon (C), sulfur and magnesium contents of the onion bulbs were significantly affected by the location in which they were grown. Bulbs grown in Muan had the greatest number of scales, thinnest scale thickness, and the highest total soluble solids (TSS) and total flavonoids (TF). Bulbs originating from Jecheon had the lowest pyruvic acid (PA), total phenolics and TF. Storage loss of bulbs from the different regions was similar in refrigerated storage, but differed in ambient temperature storage. Bulb fresh weight was positively correlated with scale thickness (r = 0.617) and cold storage loss (CSL; r = 0.398). Dry matter content was positively correlated with C (r = 0.958) and TF (r = 0.256) contents, while it was negatively correlated with CSL (r = -0.424). CSL was primarily affected by the fresh weight, as well as the dry matter, C, and PA contents of the bulbs, while ambient storage loss was primarily influenced by the amount of TSS.

• Mycobiology
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• v.48 no.5
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• pp.351-363
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• 2020

Here, we investigated fungal microbiota in the understory root layer of representative well-conserved geographically segregated natural wetlands in the Korean Peninsula. We obtained 574,143 quality fungal sequences in total from soil samples in three wetlands, which were classified into 563 operational taxonomic units (OTU), 5 phyla, 84 genera. Soil texture, total nitrogen, organic carbon, pH, and electrical conductivity of soil were variable between geographical sites. We found significant differences in fungal phyla distribution and ratio, as well as genera variation and richness between the wetlands. Diversity was greater in the Jangdo islands wetland than in the other sites (Chao richness/Shannon/Simpson's for wetland of the Jangdo islands: 283/6.45/0.97 > wetland of the Mt. Gariwang primeval forest: 169/1.17/0.22 > wetland of the Hanbando geology: 145/4.85/0.91), and this variance corresponded to the confirmed number of fungal genera or OTUs (wetlands of Jangdo islands: 42/283> of Mt. Gariwang primeval forest: 32/169> of the Hanbando geology: 25/145). To assess the uniqueness of the understory root layer fungus taxa, we analyzed fungal genera distribution. We found that the percentage of fungal genera common to two or three wetland sites was relatively low at 32.3%, while fungal genera unique to each wetland site was 67.7% of the total number of identified fungal species. The Jangdo island wetland had higher fungal diversity than did the other sites and showed the highest level of uniqueness among fungal genera (Is. Jangdo wetland: 34.5% > wetland of Mt. Gariwang primeval forest: 28.6% > wetland of the Hanbando geology: 16.7%).

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.618-624
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• 2019

This study aimed to determine the growth and carbon storage of planted Haloxylon aphyllum in the Aralkum Desert in Kazakhstan. Six sites afforested in 2000, 2005, 2009, 2010, 2013, and 2017 were selected. The root collar diameter(cm) and height(m) were measured for all H. aphyllum in 30 m×44 m plots. Biomass accumulation (g m^-2) and carbon storage(C g m^-2) were calculated using allometric equations and the carbon concentration data of Haloxylon species. The diameters varied from 2.5 cm to 4.3 cm and the height varied from 106.2 cm to 223.7 cm. The growth of H. aphyllum was not linearly related to the afforestation year or soil properties. Tree growth might have been influenced by variations in the microclimate, such as temperature, precipitation, and dust storms. The mean total biomass accumulation was 20.57g m^-2 and ranged from 2.42 g m^-2 to 64.53 g m^-2. The mean carbon storage was 9.70C g m^-2 and ranged from 1.12 C g m^-2 to 30.61 C g m^-2. These biomass and carbon storage estimates were smaller than those reported for other Central Asian deserts, but afforestation enabled the generation of vegetative cover and consequently, carbon sequestration in the manmade Aralkum Desert.

• Asian Journal of Atmospheric Environment
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• v.6 no.4
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• pp.281-287
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• 2012

Aerosol concentrations at the CC-Lag site in the Teshio Experimental Forest increased from winter to spring and sometimes showed extremely high values associated with Kosa and/or forest-fire events. The range and mean of the mass concentrations of aerosol chemical species were as follows: total particulate mass, 1.2-29, 5.0; elemental carbon, 0.061-2.2, 0.43; organic carbon, 0.059-3.5, 0.79; and sulfate, 0.12-6.2, 1.8 ${\mu}g/m^3$. The total masses of the deposited particles on hybrid larch and on bamboo leaves were approximately 35 and 30 ${\mu}g/cm^2$, respectively. The amounts of soil particles on the leaves were 6 ${\mu}g/cm^2$ for the upper part of hybrid larch, 2 ${\mu}g/cm^2$ for the lower part of hybrid larch, and 1 ${\mu}g/cm^2$ for Sasa bamboo leaves. The amounts of deposited black carbon were 2.3 ${\mu}g/cm^2$ for the upper part of hybrid larch, 0.6 ${\mu}g/cm^2$ for the lower part of hybrid larch, and 0.2 ${\mu}g/cm^2$ for Sasa bamboo leaves. Half of the total deposited particular mass was attached on the hybrid larch; however, most of the total deposited mass was adhered on the Sasa bamboo leaves. Regardless of the species, there tend to be more deposited particles on the leaves in the upper part than in the lower part, with only a few meters height difference. Comparing the composition of the deposited particles to that of the atmospheric aerosols without any size cut, the fractions of water-soluble material sulfate and sea salt in the deposited aerosols were about one tenth and one hundredth lower than that in the aerosols, respectively. On the basis of the measured concentration and the deposited amount on leaves, the deposition velocity of black carbon was estimated to be approximately 0.5 cm/s.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.2
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• pp.41-54
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• 2016

The production of high quality seedlings is a very important phase in silvicultural systems for successful reforestation or restoration. The purpose of this study was to measure both growth performances and nutrient responses of Fraxinus rhynchophylla and Pinus densiflora seedlings, which are commercially planted in Korea, according to soil improvement treatments. We applied 8 types of soil improvements: control with no treatment, compost B and compost Y as organic materials, vermiculite, perlite, two level of zeolite, and mix of vermiculite, perlite, and zeolite as inorganic materials in a permanent national nursery. Only compost B treatment significantly increased soil pH, organic matter, total nitrogen, available phosphorus, exchangeable potassium and calcium at the 0-10 cm soil depth. The growth of F. rhynchophylla and P. densiflora was the highest at the compost B treatment and the lowest at the vermiculate treatment. Compost B treatment allocated more carbon to aboveground than belowground by 39%, especially to foliage. On the vector diagnosis, there was 'shortage' on compost B treatment because of all increases of N contents, N concentrations, and growth and 'over accumulation' on vermiculite treatment because of more N uptake compared with dry weight increase. This study suggested optimal use of soil improvements is very important to improve soil quality in a permanently used nursery.

• Journal of Ginseng Research
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• v.39 no.1
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• pp.81-88
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• 2015

Background: In Changbai Mountains, Panax ginseng (ginseng) was cultivated in a mixture of the humus and albic horizons of albic luvisol in a raised garden with plastic shade. This study aimed to evaluate the impact of ginseng planting on soil characteristics. Methods: The mixed-bed soils were seasonally collected at intervals of 0-5 cm, 5-10 cm, and 10-15 cm for different-aged ginsengs. Soil physico-chemical characteristics were studied using general methods. Aluminum was extracted from the soil solids with $NH_4Cl $(exchangeable Al) and Na-pyrophosphate (organic Al) and was measured with an atomic absorption spectrophotometer. Results: A remarkable decrease in the pH, concentrations of exchangeable calcium, $NH_4^+$, total organic carbon (TOC), and organic Al, as well as a pronounced increase in the bulk density were observed in the different-aged ginseng soils from one spring to the next. The decrease in pH in the ginseng soils was positively correlated with the $NH_4^+$ (r=0.463, p<0.01), exchangeable calcium (r=0.325, p<0.01) and TOC (r= 0.292, p < 0.05) concentrations. The $NO_3^-$ showed remarkable surface accumulation (0-5 cm) in the summer and even more in the autumn but declined considerably the next spring. The exchangeable Al fluctuated from $0.10mg\;g^{-1}$ to $0.50mg\;g^{-1}$ for dry soils, which was positively correlated with the $NO_3^-$ (r=0.401, p < 0.01) and negatively correlated with the TOC (r=-0.329, p < 0.05). The Al saturation varied from 10% to 41% and was higher in the summer and autumn, especially in the 0-5 cmand 5-10 cm layers. Conclusion: Taken together, our study revealed a seasonal shift in soil characteristics in ginseng beds with plastic shade.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.610-617
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• 2015

The impact of 1 pound of nitrous oxide ($N_2O$) on warming the atmosphere is almost 310 times that of 1 pound of carbon dioxide. Agricultural soil management is the largest source of $N_2O$ emissions, accounting for about 73% of total $N_2O$ emissions. This study was conducted to evaluate the nitrous oxide emission in the cultivation of soybean during the first year of No-tillage (NT) and Conventional-tillage (CT) practices, under the various conditions such as different kinds of fertilizers, soil temperature, and moisture level. In the experiment, we set CT and NT treatments into 4 different groups - control treatments (no fertilization), green manure treatments, chemical fertilizer treatments and organic manure treatments. In the case of chemical fertilizer treatments, $N_2O$ emission of NT treatment was 7.78 to 22.59% lower than CT treatment. In organic manure treatment, $N_2O$ emission of NT treatment was 6.62% higher than CT treatment in August. But In July and September, $N_2O$ emission of NT treatment was 9.50% 28.38% lower than CT treatment, respectively. Soil temperature was correlated with $N_2O$ emission positively. In the future, continued long-term research on influence of various environmental factors on the generation of $N_2O$ and the economic value of no-till farming is required.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.473-481
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• 2022

Environment-friendly harvesting is practiced to maintain ecosystem, landscape, and forest protection functions. The present study was conducted at Simgok-ri, Sinbuk-myeon, Pocheon, Gyeonngi-do, where a 41-50-year-old Japanese larch forest was harvested in an environment-friendly manner from 2017 to 2019. The dynamics of organic matter in this forest were investigated at three years after the harvest. Specifically, organic matter content was measured on the forest floor and in overstory biomass, litterfall, and soil up to 30 cm in depth from June 2020 to January 2021. Owing to the harvest, the amount of overstory biomass of the Japanese larch stands decreased from 142.22 to 44.20 t ha^-1. On the forest floor, the amount of organic matter was 32.87 t ha^-1 in the control plots and 23.34 t ha^-1 in the harvest plots. Annual litterfall was 4.43 t ha^-1 yr^-1 in the control plots and 1.16 t ha^-1 yr^-1 in the harvest plots. Soil bulk density in the B horizon was 0.97 g cm^-3 in the control plots and 1.06 g cm^-3 i n the harvest plots. Soil organic matter content was 11.5% in the control plots and 12.8% in the harvest plots. The total amount of soil organic matter did not differ significantly between the control plots (245.21 t ha^-1) and harvest plots (263.92 t ha^-1), although the amount of soil organic matter tended to be higher in the harvest plots. The total amount of organic matter in the forest was estimated to be 406.48 t ha^-1 in the control plots and 338.21 t ha^-1 in the harvest plots. In the harvest plots, the ratio of aboveground organic matter decreased to 13.1% and soil organic matter increased to 78.0%, indicating that the distribution of organic matter changed significantly in these plots. Overall, the carbon accumulated in aboveground biomass was substantially reduced by environment-friendly harvesting, whereas the soil carbon level increased, which played a role in mitigating the reduction of system carbon in the forest. These results highlight one possible resolution for forest management in terms of coping with climate change. However, given that only three years of environment-friendly harvesting data were analyzed, further research on the dynamics of organic matter and tree growth is needed.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.382-389
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• 2020

Soil properties in opencast mines are a key factor in reclamation (revegetation) of mining areas. In this study we determined the soil physical and chemical properties of kaolinite tailings, reclaimed areas, and adjacent natural red pine (Pinus densiflora S. et Z.) forests in kaolinite opencast mines in Sancheong-gun, Gyeongsangnam-do. Six sites were chosen for collection of soil samples to determine soil physical and chemical properties at a soil depth of 10 cm. Soil bulk density was significantly higher (P < 0.05) in the kaolinite tailings (1.51 g·cm-3) than in the reclaimed areas (1.19 g·cm-3) and red pine forests (0.93 g·cm-3), whereas air phase in the kaolinite tailings (14.2%) was significantly lower than in the red pine forests (32.6%). Clay content in the red pine forests was significantly higher than in the reclaimed areas (18.7%) or kaolinite tailings (14.8%), whereas soil structural stability index was significantly lower in the reclaimed areas (1.61%) and kaolinite tailings (0.87%) than in the red pine forests (7.75%). Soil pH was significantly higher in the kaolinite tailings (pH 6.68) and reclaimed areas (pH 6.27) than in the red pine forests (pH 5.31). Soil organic carbon and total nitrogen were significantly higher in the red pine forests (C: 36.03 mg·g-1; N: 2.08 mg·g-1) than in the reclaimed areas (C: 5.00 mg·g-1; N: 0.31 mg·g-1) than in the kaolinite tailings (C: 2.12 mg·g-1; N: 0.07 mg g-1). The amount of available phosphorus was not significantly different among the three treatments. The concentration of exchangeable potassium was significantly lower in the kaolinite tailings (0.08 cmolc·kg-1) than in the reclaimed areas (0.21 cmolc·kg-1) and red pine forests (0.30 cmolc·kg-1). These results indicate that, because of high soil bulk density and low soil organic carbon, total nitrogen, available phosphorus, and exchangeable potassium in kaolinite tailings and reclaimed mining areas, soil nutrient management is needed in order to reclaim the vegetation in these type of areas.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.249-256
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• 2021

Napa cabbage (Brassica campestris var. Pekinensis) is the main material of Kimchi so that important crop in South Korea. There are two typical napa cabbage cropping systems in the alpine area. One is cultivating napa cabbage annually while another is cultivating napa cabbage and potato biennially. In this research, we evaluated soil physiochemical properties, yield, and mineral contents of napa cabbage depending on two cropping systems. As a result, organic matter, available P₂O₅, exchangeable K⁺ was decreased after six-years of cultivation on both cropping systems. However, soil pH was only decreased in a continuous napa cabbage cropping system. Soil porosity is also decreased in both cropping systems on topsoil while is increased in rotation with potato on subsoil. The rotation system showed a significantly higher yield with a higher value of leaf and napa cabbage size than the continuous cropping system. Total nitrogen, Ca²⁺, and Ma²⁺ were increased and total carbon and phosphate decreased in both cropping systems after six-years. Especially, total nitrogen and Mg²⁺ were significantly higher in the continuous system while Ca²⁺ was higher in the rotation system. In conclusion, the cropping system influences soil physiochemical properties and plant production in an agricultural field.