• ALGAE
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• v.29 no.3
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• pp.217-225
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• 2014

Land-based seaweed (Gracilaria) cultivation systems may provide products with high quality and biosafety for human consumption, as well as for other high value applications. However, a limitation for this land based system is high management costs. The objective of this study was to determine if the management costs for Gracilaria cultivation can be reduced without a decrease in productivity by using $CO_2$ injection along with a high stocking density and high photosynthetically active radiation (PAR), and commercially available fertilizers. When Gracilaria tikvahiae was cultivated at a high stocking density and high PAR, coupled with $CO_2$ enhancement, the productivity was significantly higher than that at a lower stocking density, low light without $CO_2$ injection. We also found that G. tikvahiae grown in a medium of commercially available fertilizer (Jack's Special, JS) showed a similar growth rate and productivity to that grown in von Stosch's enriched (VSE) seawater, while the cost for JS media is only 2% of the cost for VSE. These results suggest that $CO_2$ injection and commercial fertilizer may be a potential way to provide sustainability in land-based Gracilaria cultivation systems.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.21-27
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• 2013

The present study explored the way to desalinate seawater for agricultural irrigation using forward osmosis (FO) process using liquid fertilizer as draw solution. FO experiments were performed in a cross flow mode using flat sheet FO membrane. The effect of membrane orientation, flow rate, and draw solution concentration on the performance of forward osmosis was investigated by measuring water flux of forward osmosis membrane. The water flux when the draw solution was placed against the membrane active layer was lower than the water flux when the feed solution was placed against the membrane active layer. This results indicated that the decrease of effective osmotic pressure by dilutive internal concentration polarization was less than that by concentrative internal concentration polarization. Increasing flow rate from 66.7 to 133.1 $cm^3$/min resulted in increase of the water flux when the membrane active layer orient to draw solution and feed solution, respectively. The reduction of resistance to water flow increased water flux at higher flow rate. The water flux of FO membrane increased with increasing draw solution concentration from 10000 to 30000 mg/L. The water flux for $KH_2PO_4$ draw solution was similar to that for commercial fertilizer. Optimization of FO process would contribute to economically desalinate brackish water for agricultural use.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.406-409
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• 2005

Since 2003, Korean government has restricted landfill application of organic waste, which shares approximately 56% of total waste sludge from municipal and industrial wastewater treatment plants. In addition, enforcement of the ocean disposal prohibition law is effective from 2005. Organic sludge was composted for the purpose of converting to organic fertilizer. After moisture content was regulated with bulking agents aerobic treatment performed. When composting was conducted, commercial and activated microbe materials, identified from soil were seeded in sewage sludge. Carbon dioxide production was increased sharply after 24 hours. Temperature and pH of compost reached to $66.2^{\circ}C$ and 8. Heavy metals were lower than their regulatory limits, which enable it to utilize as organic fertilizer.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.1
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• pp.5-14
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• 2019

The objective of this study was investigated the effect of organic fertilizer(OF) application on the grain yield, protein content, and soil chemical properties in rice cultivation to evaluate the replacement ratio of OF based on basal fertilization of inorganic(nitrogen) fertilizer, In case of soil 1 with optimum range of organic matter for rice growth, the grain yield of rice in 70% and 100% treatments of OF were higher than the other treatments. In soil 2 with higher than the optimum range of soil organic matter, the grain yield of rice of NPK, 30%, 70%, 100%, and 300% treatments of OF showed no significant difference. When the protein criteria of rice quality was below 7%, the treatment of 30%, 70%, and 100% using OF in soil 1 were satisfied with protein criteria of rice. In case of soil 1, ammonium nitrogen content, electrical conductivity, and the organic matter in 30%, 70%, 100%, 300% treatments of OF showed similar tendency to NPK treatment. These results suggested that the substitution ratio of OF 70~100% could be appropriate to increase the yield and commercial quality for rice.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.484-489
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• 1998

The GLEAMS nutrient submodel was evaluated to predict nutrient losses in surface runoff following application of two rates (9 and 18 t/ha) of poultry litter and a recommended rate of commercial fertilizer on corn plots. Nutrient submodel was evaluated with calibrated runoff and sediment losses to the observed field data. Simulation of nitrogen transformation effects on nitrogen losses in surface runoff did not agree with field data. The model simulated higher NH$_4$-N than NO$_3$-N losses in surface runoff, while field data showed the opposite.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.201-206
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• 2009

It is generally accepted that organic materials are a significant factor on the soil aggregation formation but little information exists on how the formation and stabilization of aggregates in reclaimed tidelands. In this work, the effects of organic materials on the soil aggregate formation in reclaimed tidelands were determined. The soil was treated with 5 cm-size chopped fresh italian ryegrass residues (fresh organic material), commercial livestock compost with swine manure and sawdust (by product fertilizer), and fresh organic material + by product fertilizer (1 : 1 w/w) after ploughing at 20 cm soil depth. The three organic materials applied $2,000kg\;10a^{-1}$ every year. Water stable aggregate was estimated by wet-sieving method. Three years after the beginning of the experiment, water stable aggregate rate and MWD (mean weight diameter) were higher fresh organic material treatment than two other treatments. For improvement of physical property and structure of soil in reclaimed tidelands, fresh organic material treatment was more suitable than two other treatments.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.683-693
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• 2014

This study was carried out to investigate the characteristics of the organic liquid fertilizer and find out optimum fermentation conditions of Effective Microorganisms (EM) including ascidian tunic. During the EM fermentation by adding ascidian tunic, electrical conductivity (EC) was increased, contrast to decrease the pH value, on related to the initial dosage molasses rate. Additionally, the total nitrogen quantity was shown to be increased on EM fermentation and the most effective increasing was recorded up to 220% on more than 15% molasses dosage condition. The phosphorus quantity was to be maximum rate on 21th of EM fermentation, and other contents, such to potassium, calcium, magnesium, sodium, had be shown an increasing patten during the fermentation period. After the EM fermentation, the concentration of hazardous material (Zn, As, Cd, Cu, Cr, Hg, Ni, pb) was measured below than the official criteria for commercial fertilizer. As a effective material in fermentated fertilizer, the 29 kinds free amino acids were detected and their total concentration was measured to 7080.94 mg/L.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.251-253
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• 1963

Six corrosion inhibitors for cooling water use were evaluated by means of a corrosometer in a laboratory bench scale test. A steel probe (Alloy 1020) was exposed and checked for the extent of corrosion in a recirculating water system, changing inhibitors and their concentrations at $40^{\circ}C$. A 95% inhibition was provided at the following concentrations of inhibitors. 50 ppm sodium hexametaphosphate 50 ppm commercial inhibitor A 50 ppm commercial inhibitor B 100 ppm disodium phosphate 200 ppm sodium chromate Sodium silicate was found to be use-less in this test. It was also observed that some inhibitors worked less effectively on the acid-cleaned steel probe.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.197-205
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• 2015

This study was performed to identify the effect of fertilizer application and planting method on growth and yield of 'Seolhyang' strawberry during seedling raising. According to the concentration of fertilizer applied, the height of daughter plants was the highest at an EC of $0.8dS{\cdot}m^{-1}$. Leaf number and crown diameter were greatest at an EC of $0.6-0.8dS{\cdot}m^{-1}$. In the first measurement, root number was highest in non-fertilizer application, while root weight was heaviest in non-fertilizer application and EC $0.4dS{\cdot}m^{-1}$. The higher the concentration of fertilizer applied as culture media, the lower the growth rate. Thirty days after planting on the main field, plant height and number of new leaf were highest at an EC of $0.8dS{\cdot}m^{-1}$. However, no significant difference was found in leaf length and width and chlorophyll content according to fertilizer application. Marketable yield of 25 g or higher was greatest in EC $0.6dS{\cdot}m^{-1}$. In contrast, no significance was found in total marketable yield at an EC of $0.4-0.8dS{\cdot}m^{-1}$. Aconsistent pattern was exhibited in the growth of 1-5 harvesting flower clusters according to planting method. The length of leaf and flower cluster was short and chlorophyll content was low, when bed soil was removed 100% in harvesting of the first flower cluster. In all treatment, leaf length was shortened until harvesting of the second and third flower cluster, but rapidly lengthened in harvesting of the third and fourth flower clusters. Moreover, the length of flower cluster had a increasing tendency from harvesting of the third flower cluster. However, chlorophyll content was reduced continuously until harvesting of the fifth flower cluster, and was lowest in harvesting of the fourth flower cluster without removal of bed soil. Total yield was greatest in treatment of crown removal in bed soil between November and May. Late marketable yield between March and May was highest in treatment of 100% bed soil removal, followed by treatment of crown removal. Marketable yield of 25 g or higher was greatest in treatment of crown removal between December and February, while greatest in treatment of 100% bed soil removal between March and May.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.31-39
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• 2017

From July to August 2013, liquid fertilizers produced at 180 liquid manure public resource centers and liquid fertilizer distribution centers were collected. The maturity of liquid fertilizers was measured using the mechanical maturity measurement device. The nutrient contents (nitrogen, phosphorus, and potassium), physicochemical properties, and heavy metal content of 46 liquid fertilizers were investigated in this study. We used a matured liquid fertilizer with a total number of 46, with number of 7 for Gyeonggi-do, 3 for Chungcheongbuk-do, 2 for Chungcheongnam-do, 13 for Jeollabuk-do, 5 for Jeollanam-do, 3 for Gyeongsangbuk-do, 11 for Gyeongsangnam-do, 1 for Daejeon, and 1 for Jeju-do. The physicochemical properties were as follows: pH 8.0, EC 11.6 mS/cm, SS 5,188 mg/L, TKN 847mg/L, ${{NH_4}^+}-N$ 317 mg/L, ${{NO_3}^-}-N$ 170 mg/L, Org-N 360 mg/L, TP 193 mg/L, and TK 2,557 mg/L. The total amount of NPK was 3,596 mg/L. The total amount of N-P-K was as follows: a number of 2 at 1,000-2,000 mg/L (4%), a number of 17 at 2,000-3,000mg/L (37%), a number of 11 at 3,000-4,000mg/L (24%), and a number of 16 at 4,000mg/L or more (35%). Thus, 41% of the mature liquid fertilizers were below the official standard of commercial fertilizer (livestock manure liquid fertilizer) (0.3% of the total amount of N-P-K). Most of the N-P-K total amount showed non-uniform characteristics of low nitrogen and low phosphoric acid due to the potassium concentration. The average heavy metal content in the matured liquid fertilizer was as follows: As, not detected; Cd, 0.01 mg/kg; Hg, not detected; Pb, 0.02 mg/kg; Cr, 0.14 mg/kg; Cu, 6.89 mg/kg; Ni, 0.44 mg/kg; and Zn, 20.70 mg/kg. Thus, the official standard of commercial fertilizer was satisfied in all categories, indicating a safe level.