• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.2
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• pp.139-146
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• 2000

A trial was carried out to investigate the effect of fermented saw-dust pig manure (FSP) and N fertilizer application on physical, chemical properties and microbial population of soil on Cheju brown volcanic ash pasture during the period from September, 1997 to January, 1999. Average soil N contents during 3 different periods, August and October, 1998, and January, 1999 were 0.39, 0.41 and 0.39% for fertilizer N level 0, 150 and 300kg/ha, respectively. Soil N contents determined in January, 1999, was significantly increased by an increase of fertilizer N. Nitrogen contents in the soil applied with 0, 3, 6 and 12 tons 1 ha of FSP were 0.43, 0.40, 0.38 and 0.38%, respectively, showing decreasing tendency of soil with increasing levels of FSP application. Soil N contents determined in August, 1998 and January, 1999, were significantly decreased by increasing levels of FSP application. Organic matter contents of the soil applied with N 0, 150 and 300 kg/ha was 8.04, 8.37, and 9.08%. Soil organic matters determined on the 1st and 2nd period trended to increase with increasing level of fertilizer N. FSP application significantly decreased organic matter contents of pasture soil, (9.14, 8.79, 8.28 and 7.78% OM in soil applied with FSP 0, 3, 6 and 12 tonlha of FSP), respectively. Soil OM determined in October, 1998, also showed a significant decrease with increasing level of FSP. Soil pH, available phosphorus, exchangeable K, Ca, Mg and Na in soil studied were not influenced by fertilizer N or FSP application during all three periods. N application tended to increase soil bacteria count, ($27.0\;{\times}\;10^4\;cfu/g,\;29.4\;{\times}\;1-^4\;cfu/g$ and $53.6\;10^4\;cfu/g$ in the soil applied with 0, 150 and 300 kg N/ha, respectively). The number of colonies of soil bacteria and fungi determined in June and October, 1998 was not increased remarkably by FSP application, but the number of colonies of bacteria determined in March, 1998 showed a significant increase with increasing level of FSP application. In conclusion, N contents and OM of soil increased with increasing level of N application, but decreased with increasing level of FSP application.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1231-1238
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• 2008

This study was performed to evaluate the treatability of food waste leachate using lab-scale two-phase anaerobic digestion system. Effects of influent pH, hydraulic retention time (HRT), and recycle of methanogenic reactor effluent to the thermophilic acidogenic reactors were investigated. For methanogenic reactors, effects of internal solids recycle and temperature were studied. Performance of the acidogenic reactors was stable under the conditions of influent pH of 6.0 and HRT of 2 d with the recycle of methanogenic reactor effluent, and acidification and VS removal efficiency were about 30% and 40%, respectively. Up to the organic loading rate (OLR) of 7 g COD/L/d, effluent SCOD values of mesophilic and thermophilic methanogenic reactors either lower or kept the same with the internal solids recycle. Also, decreasing tendency in specific methane production (SMP) due to the organic loading increase became diminished with the internal solids recycle. Mesophilic methanogenic reactors showed higher TCOD removal efficiency and SMP than thermophilic condition under the same OLR as VSS was always higher under mesophilic condition. In sum, thermophilic acidogenesis-mesophilic methanogenesis system was found to be better than thermophilic-thermophilic system in terms of both organic removal and methane production.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.351-357
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• 1987

A laboratory experiment was conducted to find out the effect of organic fertilizer as Bio-com$^{(R)}$ on the changes of pH and Eh values, gas evolution, ammonification and nitrification, and microbial population with farmer's compost and refused mushroom compost in submerged paddy condition. The results obtained are summarized as follows: 1. Application of compost and refused mushroom compost was increased the pH values than that of NPK alone. Organic fertilizer of Bio-com$^{(R)}$ showed the same results of the farmer's compost or refused mushroom compost. 2. Population of soil microbes as bacteria, actinomycetes and fungi was increased by application of compost, refused mushroom compost and Bio-com$^{(R)}$. Moreover, the results were pronounced more with the addition of NPK. 3. The application of Bio-com$^{(R)}$ was effected to the increase of the amount of $NO_3-N$ and the rate of nitrification than NPK, farmer's compost or refused mushroom compost. 4. The amounts of evolved gases as $CH_4$, $CO_2$, and $N_2O$ were not much differed with application of kinds of compost and NPK, but little increasing tendency was observed in application of NPK than that of NPK+kinds of compost.

• Ocean Science Journal
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• v.40 no.3
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• pp.167-176
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• 2005

A time-series sediment trap was deployed at 1,034 m water depth in the eastern Bransfield Strait for a complete year from December 25, 1998 to December 24, 1999. About 99% of total mass flux was trapped during an austral summer, showing distinct seasonal variation. Biogenic particles (biogenic opal, particulate organic carbon, and calcium carbonate) account for about two thirds of annual total mass flux $(49.2\;g\;m^{-2})$, among which biogenic opal flux is the most dominant (42% of the total flux). A positive relationship (except January) between biogenic opal and total organic carbon fluxes suggests that these two variables were coupled, due to the surface-water production (mainly diatoms). The relatively low $\delta^{13}C$ values of settling particles result from effects on C-fixation processes at low temperature and the high $CO_2$ availability to phytoplankton. The correspondingly low $\delta^{l5}N$ values are due to intense and steady input of nitrates into surface waters, reflecting an unlikely nitrate isotope fractionation by degree of surface-water production. The $\delta^{l5}N$ and $\delta^{l3}C$ values of sinking particles increased from the beginning to the end of a presumed phytoplankton bloom, except for anomalous $\delta^{l5}N$ values. Krill and the zooplankton fecal pellets, the most important carriers of sinking particles, may have contributed gradually to the increasing $\delta^{l3}C$ values towards the unproductive period through the biomodification of the $\delta^{l3}C$ values in the food web, respiring preferentially and selectively $^{12}C$ atoms. Correspondingly, the increasing $\delta^{l5}N$ values in the intermediate-water trap are likely associated with a switch in source from diatom aggregates to some remains of zooplankton, because organic matter dominated by diatom may be more liable and prone to remineralization, leading to greater isotopic alteration. In particular, the tendency for abnormally high $\delta^{l5}N$ values in February seems to be enigmatic. A specific species dominancy during the production may be suggested as a possible and speculative reason.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.951-958
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• 2003

Twenty-four cultivars of colored rice seeds were collected inside and outside Korea, and the antioxidant and antimutagenic activity was determined for the solvent-fractionated layers of their bran parts lipid soluble fraction, pigment containing fraction, and pigment component per se. As the serial organic solvent extraction proceeded, the overall tendency of antioxidant activities declined with increased chemical homogeneity of each fraction. This markedly showed the low antioxidativities of the pigment components from LK 1-3-6-12-1-1 and Gillimhukmi. Even all the colored rice cultivars, with considerable antimutagenic activity in 70% ethanolic extract, exhibited mutagenicity when measured with its pigment containing fraction (wx 124-163-45-7-1-1-1 and LKlB-2-1-1 being the strongest). The pigment content in each colored rice seeds decreased in the order of IR 17491-5-4-3-3>LK 1-3-6-12-1-1>LK 1D-2-12-1>RGS No.336, Elwee. In addition, a substantial difference in both chemical composition of the constituents and its amount could be found between the colored rice and cooking rice cultivars. This revealed that, compared to cooking rice, major components of organic solvent fractions from colored rice probably have long hydrocarbon chain moieties.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.70-76
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• 2003

Continuous anaerobic hydrogen production with a mixed culture was investigated. With a sucrose concentration of 5g COD/L in the feed, hydrogen production exceeded $0.5mole\;H_2/mole\;hexose$ was found at the early stage, however it did not maintain longer than 9days. It was assumed that the failure was caused by insufficient active hydrogen producing bacteria in the reactor. Therefore, effects of pH control, repeated heat treatment and substrate concentration on sustainable continuous anaerobic hydrogen production was examined to find out operating conditions to sustainable hydrogen production. Decrease of hydrogen production was not overcome by only pH control at 5.3. Repeated heat treatment could recover hydrogen producing activity without any external inoculum supply. However, frequent heat treatment was needed because the treated sludge also showed the tendency in decrease of hydrogen production. With a sucrose concentration of 30g COD/L in the feed, hydrogen production maintained $1.0-1.4mole\;H_2/mole\;hexose$ in continuously stirred tank reactor and $0.2-0.3mole\;H_2/mole\;hexose$ in anaerobic sequencing batch reactor) for 24days. More than 90% of soluble organics in effluent was organic acids, in which n-butyrate was the most one.

• The Korean Journal of Ecology
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• v.27 no.6 s.122
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• pp.355-361
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• 2004

In order to elucidate the ecophysiological characteristics of coastal plants, we collected them on salt marsh and sand dune, and analyzed inorganic ($Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+}$) and organic solutes (soluble carbohydrate, glycine betaine). Chenopodiaceous plant species (Atriplex gmelini, Salicornia europaea, Salsola collina, Suaeda glauca, Suaeda japonica) showed a tendency to accumulate inorganic ions such as $Na^+\;and\;Cl^-$ instead of $K^+$. However, Chenopodium serotinum which lives in ruderal habitat contained more $K^+$ and less $Na^+$ than the other Chenopodiaceous plants. Most Chenopodiaceous plant species maintained very low level of soluble $Ca^{2+}$ and relatively low concentration of carbohydrates and showed high concentration of glycine betaine which is among the most effective known compatible solutes in the leaves of plant under drought and saline conditions. On the other hand, plant species which belong to Gramineae (Ishaemum anthephoroides, Phragmites communis, Zoysia sinica) and Cyperaceae (Carex kobomugi, Carex pumila) absorbed $K^+$ selectively and excluded $Na^+\;and\;Cl^-$ effectively regardless of habitat conditions, and they accumulated more soluble carbohydrate as osmoticum than Chenopodiaceous plants. These results suggested that physiological characteristics such as high storage capacity for inorganic ions (especially alkali cations, chloride) and the accumulation of glycine betaine in chenopodiaceous plants and $K^+$-preponderance, an efficient regulation of ionic uptake (exclusion of $Na^+\;and\;Cl^-$) and the accumulation of soluble carbohydrate in monocotyledonous plants enable them to grow dry and saline habitats.

• Journal of the Korean earth science society
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• v.33 no.6
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• pp.510-518
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• 2012

The Holocene climate change has been studied based on humus analysis of sediments that came from the Nam River basin in the Jinju, Gyeongnam. Humus and soil organic carbon analyses were performed to interpret the climate change and OSL dating and radiocarbon dating were conducted to determine the age of the sediments. The age determinations revealed that the sediments were formed approximately from $10,000{\pm}100$ yr. BP to $4,370{\pm}50$ yr. BP (2,970 BC) The deposits were classified into five layers based on sediments color and texture, and the climate change of each layer has been interpreted. The general climate was found out to be warm. The study result illustrated that section I was the lowest layer and section V the highest among the five surveyed sections. One the other hand, relatively cold events were detected in the sections ranging from I and II to III in terms of temperature. In term of humidity, sections II and III are estimated to have been relatively dry. Sections IV and V were relatively warm and dry, and the section IV tends to be warmest of the entire sedimentary. In addition, there is a tendency that the total soil organic carbon shows relatively high values under the cooler and humid climatic condition.

• Korean Journal of Organic Agriculture
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• v.32 no.1
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• pp.75-90
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• 2024

Biochar is a solid substance with a high carbon content, as it is made out of biomass pyrolyzed under the condition of limited oxygen. This product has attracted attention as an environment-friendly soil amendment because it contributes to carbon neutrally and has improvement effects on the soil environment. This study conducted an experiment to evaluate soil physiochemical properties and microbial community changes in a melon greenhouse according to the applied amount of biochar to investigate the growth characteristics and yields of melons accordingly. In soil physical properties, an increase in the applied amount of biochar resulted in a decrease in bulk density and an increase in porosity of the soil, improving air permeability. In soil chemical properties, an increase in the applied amount of biochar led to a increasing of pH, organic matter and available phosphate content. In the growth characteristics of melons, there was a growing tendency of plant height, leaf length and leaf width according to the increasing application of biochar until 10,000 kg/ha. Moreover, melon yields also increased as the amount of biochar, 13~16% higher in 10,000 kg/ha biochar application than no treatment. Compared differences among microbial communities in the soil according to the application of biochar and found that plant beneficial bacteria dominated in biochar treatments. This study demonstrated the potential of biochar as an effective soil amendment in melon greenhouse by showing improvements in soil physicochemical properties and microbial communities.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.4
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• pp.91-102
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• 2009

In this study, to estimate the transforming (runoff and leachate) rate of the organic fertilizer made of livestock resources to farm land, laboratory scale test was conducted and the results were obtained as follows: The runoff volume from farm land showed the tendency of increase according to the increase of rainfall intensity. The most rainfall leachated into the underground at the rainfall intensity of 20mm/hr, and rainfall of 5L or less leachated at the rainfall intensity of > 32.4 mm/hr. This shows that surface runoff largely depends on the rainfall intensity when soil characteristic and hardness are similar in each site. When liquid compost was fertilized, the surface runoff was similar with the results from the reactor fertilized by compost, and leachate flow was found to be lower than compost. The runoff ratio of contaminant parameters from farm land were BOD 0.00003,, $COD_{cr}$ 0.00006, TN 0.00056, TP 0.00011, TOC 0.00005, Especially, the runoff ratio of TN showed 10 folds higher than other parameters. On the other hand, the runoff ratio of SS showed higher value of 0.001, and colloid particles of soil caused this result rather than the leachate from compost fertilizer. At all ranges of rainfall intensity, fertilizer removal ratio by farm land was found to be 94.9~98.4% for compost and 85.8~98.1% for liquid compost in terms of BOD. For TN, it resulted in 96.6~98.4% for compost and 97.2~98.5% for liquid compost, and thus the most fertilizer from livestock resources were shown to be reduced through farm land application.