• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.694-703
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• 2012

To understand the characteristics of sedimentary and benthic environments in habitats of naturally-occurring intertidal benthic macroalgae, various geochemical parameters of sediment (grain size, ignition loss [IL], chemical oxygen demand [COD], and acid volatile sulfur [AVS]) and pore water (temperature, salinity, pH, and nutrients) were measured in the southern intertidal zone of Hampyeong Bay at two month intervals from April to October 2009. Ecological characteristics including the distribution and biomass of benthic macroalgae were also investigated. Benthic macroalgae were distributed below 4 to 5 m depth from mean sea level near the lower portion of the intertidal zone where air exposure time is relatively short. The distribution area and biomass of benthic macroalgae gradually decreased during the study period. The surface sediments in the benthic algal region were mainly composed of finer sediments, such as slightly gravelly mud and mud. The temperature, salinity, pH, and nutrient concentrations (except dissolved inorganic nitrogen) in pore water did not differ in regions with and without benthic macroalgae, whereas the mean grain size and the concentrations of IL, COD, and AVS in sediments were much higher in regions harboring benthic macroalgae. The correlation between mean grain size and IL in sediments displayed two distinct gradients and the slope was much steeper in regions harboring benthic macroalgae, indicating that the content of organic matter in benthic algal region is not solely dependent on mean grain size. Our results indicate that the benthic macroalgae in the southern intertidal zone of Hampyeong Bay play an important role in the accumulation of organic matter in sediment.

• 한국해양학회지
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• v.22 no.3
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• pp.191-206
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• 1987

Keum River discharges 6.4billion tons of fresh water annually into the Yellow Sea. More than 60% of the total discharge is concentrated in summer, differentiating distinct low-discharge and high-discharge periods for the estuarine environment. The concentration of SPM(Suspended Particulate Matter) is, in general, very high, except sometime during rainy season, and turbidity maximum is often observed, especially during spring-tides(Lee and Kim, 1987).

• Culinary science and hospitality research
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• v.15 no.1
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• pp.59-66
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• 2009

To investigate the physicochemical characteristics of garlic(Allium sativum L.), general composition, mineral, vitamin C, free sugar and total acidity were determined in nine sample groups from Daejeong Jeju(DJ; Alttre, Gasiorum, Seoyukgaeri), four from Korea domestics(KD; Danyang, Uiseong, Taean and Namhae), and one from China. The average composition of the group from DJ included 63.0% of water, 35.6% of organic matter, and 1.40% of inorganic matter, which were similar to that of the group from KD. The contents of magnesium, phosphorus and sodium in the group from DJ were higher than those of the group from KD, whereas the contents of iron and calcium and total acidity showed a similar level. The mean vitamin C concentration in the group from DJ, especially from Alttre, was much higher than that in the groups from KD and China. It was also observed that the free sugar content of the group from DJ(Alttre) was the highest of all other garlic groups except that from China. In conclusion, the nutrient profiles of garlic groups from Daejeong Jeju are so comparable to those from Korean domestics, and so Daejeong Jeju should be recommended as the garlic cultivation area with acceptable quality.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.41-50
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• 1987

The present study was conducted to measure and predict the leachate generation and to establish the methods of leachate control and handling by both field and lab-lysimeter studies. The change of biodegradable matter, field capacity, dry density, quantity and quality of leachate as a function of time of landilling were measured. The model based on the theory of unsaturated flow and contaminant transport in porous media was developed and simulation model was used for the prediction of movement of landfill moisture and for the strength in leachate in terms of organic and inorganic contaminant. The model constructed from the present study in terms of unsaturated decomposition and transport combined with the evapotranspiration and surface runoff showed good agreement with the results obtained by lysimeter studies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.75-79
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• 2002

This study conducted to elucidate the change of the cation content (Na$^{+}$, $K^{+}$, and $Ca^{2+}$), the L-proline content, and the sugar and starch content in the stems, roots, and leaves of three cultivars of the 30 days old seedling soybeans (Glycine max L. cv. Danwonkong, Hwang-keumkong, and Kwangankong) after 100 mM NaCl stress containing 1/2 Hoaglands nutrient solution in the sand culture. The reduction of the dry matter weight after 100 mM NaCl treatment among cultivars was higher in the order of Kwangankong, Danwonkong, and Hwang-keumkong. The highest reduction of the dry matter weight was occurred at the roots among three parts of plant. The Na$^{+}$ content increased with NaCl treatment in overall and specially greatly increased in roots and stems. The $K^{+}$ and $Ca^{2+}$ content decreased with NaCl treatment at the roots and stems. The $K^{+}$ content, however, at the leaves increased in all three cultivars with the NaCl treatment. The L-proline content with NaCl stress increased greatly. The increment of the L-proline content at the stems and roots of Hwangkeumkong was lower than that of other two cultivars, K wangankong and Danwonkong. The sugar content decreased with NaCl treatment at the stems and leaves. The starch content also decreased at the stems and leaves with NaCl treatment.aCl treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.510-516
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• 2011

Salt-affected soils are present in Pakistan in significant quantity. This experiment was conducted to assess the effectiveness of compost for reclamation and compare its efficiency with gypsum. For this purpose, various combinations of compost and gypsum were used to evaluate their efficacy for reclamation. A saline-sodic field having $pH_s$ 8.90, $EC_e$ $5.94dS\;m^{-1}$ and SAR $34.5(mmol\;L^{-1})^{1/2}$, SP (saturation percentage) 42.29% and texture Sandy clay loam, gypsum requirement (GR) $8.75Mg\;ha^{-1}$ was selected for this study. The experiment comprised of seven treatments (control, gypsum alone, compost alone and different combinations of compost and gypsum based on soil gypsum requirements). Inorganic and organic amendments (gypsum and compost) were applied to a saline sodic soil. Rice and wheat crops were grown. Soil samples were collected from each treatment after the harvest of both crops and analyzed for chemical properties (electrical conductivity, soil reaction and sodium adsorption ratio) and fertility status (organic matter, available phosphorus and potassium contents) of soil. Results of this study revealed that compost and gypsum improved chemical properties (electrical conductivity, soil reaction and sodium adsorption ratio) of saline sodic soil to the desired levels. Similarly, all parameters of soil fertility like organic matter, available phosphorus and potassium contents were built up with the application of compost and gypsum.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.63-71
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• 2021

Using fossil fuels in existing industrial systems causes a variety of social problems. Recently, many studies have been conducted on bio-refineries, which aim to actively utilize biomass to reduce the use of fossil fuels and solve various social problems. Among them, research using microalgae as a third-generation biomass has attracted considerable attention. Microalgae use inorganic matter to produce organic matter, and cell destruction is necessary to extract useful organic materials from microalgae. The extracted organic materials are currently used in various industrial fields. Numerous cell-destruction methods exist. We have investigated cell disruption by sonication, especially its efficiency. Ultrasound is a sound wave with frequencies above 20 kHz, and destroys cells by sending high energy through a cavitation that occurs, according to the characteristics of the sound wave. The Dunaliella salina microalgae used in this study was cultured in a flat-type photobioreactor. Experiments were performed using a batch low-frequency processing device. Logistic model was applied to analyze the results of cell-destruction experiments using ultrasound. The proper conditions for the most efficient cell destruction were OD 1.4(microalgae concentration)), 54watt(output power) and 200mL(microalgae capacity).

• Korean Journal of Agricultural Science
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• v.50 no.2
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• pp.231-239
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• 2023

Ammonia (NH₃) emitted from the use of fertilizers during agricultural practice generates particulate matter and odors. The application of carbonized rice husk, an eco-friendly material, is one of the measures used to reduce NH₃. The objective of this study was to evaluate the effect of the application rate and pH of carbonized rice husk on NH₃ emissions and soil quality. An experiment to assess NH₃ emissions was performed in a glasshouse using a static chamber method. The pH of the carbonized rice husk was divided into acidic, neutral, and basic groups, and the carbonized rice husk application rates were 1, 3, and 5% of the soil weight. NH₃ emissions showed a sharp increase within three days after the inorganic fertilizer was applied. Subsequently, NH₃ emissions decreased rapidly after basal fertilization compared to primary and secondary top-dressing. When carbonized rice husks were applied to soil, NH₃ emissions decreased in all treatments, and neutral carbonized rice husk was the most effective in comparison with acidic and basic carbonized rice husk. The application rate of carbonized rice husk and NH₃ emissions showed a negative correlation, and the lowest emissions were found in units with a 5% application rate. Also, there was no statistically significant difference between NH₃ emissions according to the application rate of carbonized rice husk, and when carbonized rice husks were applied at a 5% rate, soil OM increased excessively. Therefore, it is recommended to apply only 1% neutral carbonized rice husk to most effectively reduce NH₃ emissions in the soil.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.439-446
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• 2021

A field-scale study was conducted to evaluate the effect of organic matter amendments on the solubility of arsenic (As) in paddy soil and uptake by rice. Six organic matter (rice bran, rice straw, pig/cattle/fowls manure compost and swine liquid manure) were added to two polluted soils with high As (53 mg kg^-1) and low As concentration (28 mg kg^-1), and changes in soil solution constituents was monitored. The mean As concentrations in soil solution from the high As soil with rice bran, pig manure compost and swine liquid manure addition were significantly higher (0.61-1.15 mg L^-1) than that of the control (0.42-0.66 mg L^-1). Regression between As and Fe in soil solution indicated that As was attributable to reductive dissolution of Fe (hydr)oxides and it was driven by organic matter addition. Mean As concentrations in brown rice from the high As soil were 0.35-0.46 mg kg^-1, above the maximum safety level of inorganic As (0.35 mg kg^-1), and tended to be higher in organic matter amended soils than that of the control. The significant correlation between grain As and soil solution As was not observed and it was probably attributable to As tolerance of rice causing the reduction of As uptake and/or translocation to grain. However, considering the significant As release in soil solution from the high As soil and the tendency of grain As elevation after organic matter addition, it is needed to be cautious for food safety when amending organic matter to paddy soil with high As concentration.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.758-765
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• 1999

Comparative studies of the effects of rates and frequency of application of dairy slurry on herbage yield and stand persistence of alfalfa and various forage grasses have not previously been conducted. The results being reported here are part of a larger study having a primary objective of comparing the effectiveness of alfalfa (Medicago sativa L.), various grasses and alfalfa-grass mixtures for utilizing nutrients from applied dairy slurry. The objectives of this part of the study were to evaluate the effects of various rates and frequencies of application of slurry on herbage yield and stand persistence of orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.), and alfalfa-orchanrdgreass and alfalfa-reed canarygrass mixtures managed as a 4-cutting management system. A randomized complete block design with treatments in a split plot arrangement with four replicates was used. The main plots consisted of 9 fertility treatments: 7 slurry rate and time of application treatments, one inorganic fertilizer treatment, and an unfertilized control. The sub-plots consisted of the two grasses and two alfalfa-grass mixture mentioned above. Slurry was composed from stored solids scraped from the alleyways of a free-stall housing barn and water added to form a slurry having about 8% solids. Manure was pumped from a liquid spreader tank into 10.4 L garden water cans for manual application to the plots. Herbage yields within species were generally unaffected by various rates of application in the first production year. Herbage yields of grasses and alfalfa-grass mixtures the second year were generally not affected by frequency of application for the same rate of slurry applied. Slurry application resulted in greater herbage yield increases in grasses than alfalfa-grass mixtures in the 4-cutting management system. In general, herbage dry matter yields of grasses from the dairy slurry treatments equaled or exceeded yields from the inorganic fertilizer treatment. Stand ratings of grasses and alfalfa-grass mixtures were not changed by manure application rates. In this study, the highest rate of slurry ($967kg\;total\;N\;ha^{-1}$ in 1995 plus $2,014kg\;N\;ha^{-1}$ in 1996) was not detrimental to herbage yields or stand persistence of any of the species. It was concluded that applying dairy slurry to these cool-season grasses and alfalfa-grass mixtures managed in a 4-cutting system is an acceptable practice from the standpoint of herbage yield and satnd persistence and by doing so the utilization of inorganic fertilizers can be reduced.