• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.63-70
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• 1998

This study was carried out to investigate the interaction of selenate and sulfate ion in nutrient solution supplyed with selenate ion. At early growth stage, the growth of Mongolian wormwood was best at 3mM sulfate ion and 2mg/$\ell$Na$_2$SeO$_4$ treatment. As they were grown and matured, at the later growth stage, the effect of antagonism between selenate and sulfate ion on the growth of each plant decreased. At supplying with selenate ion in nutrient solution, the uptake of selenate by plant had negative correlation with sulfate ion concentration in nutrient solution. The higher sulfate ion concentration, the less selenium uptake. However, the effect of antagonistic interaction of selenate and sulfate ion on the selenium uptake increased with plant age. Whereas, the uptake of sulfate ion had positive correlation with sulfate ion concentration in nutrient solution at supplying with selenate ion in nutrient solution. The uptake of sulfate ion increased with increase of sulfate ion concentration in nutrient solution. The effect of this interaction with selenate and sulfate ion increased with growth and maturity of plant. However, at 3mM sulfate ion concentration in nutrient solution, sulfate ion concentration in plant tissue decreased markedly.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.65-75
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• 1994

The aim of this experiment was to investigate the effects of applying time of cattle slurry and fertilizing added mineral nitrogen on dry matter yield of orchardgrass and also to estimate proper levels of fertilizing nitrogen when idled arable land rapidly increased these days, which was used for the production of Orchardgrass. The results were as follows. 1. The annual yields of dry matter were produced 5.62~6.67 ton per ha when cattle slurry applied at rates of $30m^3$(average mineral fertilizer equivalent to 120kg) per ha in different dressing times. Those were higher 0.60~1.65 ton or 0.16 ton per ha than the yields from non-fertilizing or phosphrous and potassium fertilizing. 2. Relative yields of annual dry matter from mineral nitrogen fertilization of 120kg per ha were 142~146% in comparsion with control plots(cattle slurry plot or phosphrous and potassium plot). On the other hand, those of cattle slurry application were 112~133% in comparion with non-fertilizing plot. 3. The efficiencies of nitrogen on dry matter yield(kg DM/kg N) were 5.0~13.8 DM kg/N kg when cattle slurry applied to Orchardgrass at rates of $30m^3$(average mineral fertilizer equivalent to 120kg) per ha, and were 21.3~23.1kg DM/kg N at the same level fertilization of mineral nitrogen. 4. On the condition of this study, mineral nitrogen were fertilized after applying cattle slurry at rates of $30m^3$(average mineral fertilizer equivalent to 120kg) per ha in order to minimize chemical fertilizer and increase the potential production of Orchardgrass. At this situation, marginal dry matter yields of 8.48~8.63 ton per ha were obtained as the level of economic even point goint when mineral nitrogen fertilization is between 119.4 and 133.3kg per ha. It was possible to obtain the maximal dry matter yield(8.98 tons/ha) with fertilization of 202.8kg N/ha.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.4
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• pp.31-37
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• 2010

Livestock manures have a potential to be a valuable resource with an efficient treatment. In Korea, 42 million tons of livestock manure were generated in 2008, and 84 % of them were used for compost and liquid fertilizer production. Recently recycling of livestock manure for biogas production through anaerobic digestion is increasing, but its utilization in agriculture is still uncertified. In this study, there was applied co-digestate to the paddy for rice cultivation based on N supplement. Co-digestate was fertilizer fermented with pig slurry and food waste combined with the ratio of 70:30(v:v) in its volumetric basis. For assessing the safety of co-digestate, it was monitored the contents of co-digestate for seasonal variation, resulted in no potential harm to the soil and plant by heavy metals. The results showed that soil applied with co-digestate was increased in exchangeable potassium, copper and zinc mainly due to the high rate of pig slurry in co-digestate applied. Considering high salt content due to the combination with food waste, strict quality assurances are needed for safe application to arable land though it has valuable fertilizer nutrient. Leachate after treatment showed that the concentration of nitrate nitrogen washed out within two weeks. Considering the salt accumulation results in soil, it is highly recommended that the application rate of co-digestate should not exceed the crop fertilization rate based on N supplement. With these results, it was concluded that co-digestate could be used as an alternative fertilizer for chemical fertilizer. More study is needed for the long-term effects of co-digestate application on the soil and water environment.

• Journal of Mushroom
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• v.18 no.1
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• pp.45-52
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• 2020

Termitomyces albuminosus has been recognized to have the best mushrooms in China, in terms of taste and aroma. The efficacy of these mushrooms has been recorded in the botanical list. However, research on the development of their artificial culture methods is necessary. In this study, we prepared an organic solvent extract and a hot water extract to understand the development of compounds and functional foods with antioxidant and anti-inflammatory activities. The IC₅₀ value of DPPH radical scavenging activity of the hot water extract (TA4) was 1.5 mg/mL and the IC₅₀ value of the MeOH fraction (TA2) was 1.93 mg/mL. The anti-inflammatory activity was investigated by the inhibition of NO production. EtOAc fraction (TA1) is a crude extract, but 79% of NO production was inhibited at 100 ㎍/mL. NO was not produced at 200 ㎍/mL. TA1-5-6, from TA1 inhibited NO production by 15% as compared to the positive control at 15 ㎍/mL, and completely inhibited NO production at 30 ㎍/mL. No cytotoxicity was observed at 50 ㎍/mL. TA2-1-5 from the MeOH fraction (TA2) inhibited more than 75% of NO production at 30 ㎍/mL; cytotoxicity was very low even at 50 ㎍/mL. In conclusion, by selective solvent selection, it was possible to manufacture an extract with no cytotoxicity and excellent biological activities. Furthermore, the extracts showed potential for developing various functional foods and drugs.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.209-216
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• 1987

The experiments were carried out in lab. as well as in pots, to develop the agricultural usage of water swellable polymer, a kind of polyacrylic acid(K-sorb) synthesized by the Korea Advanced Institute of Science & Technology (KAIST) recently. The changes of soil physical properties and the influences to crops were investigated with various levels of K-sorb. When the K-sorb mixed with soils and soaked up distilled water, the volume of soils increased with the increase of soil available water contents and increase of K-sorb application levels. The rate increase of soil available water was higher in the coarse textured soils than in the fine while the swelling rate of soil volume showed adverse tendencies. A positive linear regression was observed between the contents of available soil water and levels of K-sorb. K-sorb application decreased bulk density and hardness due to the increase of porosity after soybean cultivation. The permeability in coarser textured soils such as sandy and coarse loamy families was decreased with the increase of K-sorb but in the medium textured soils it was opposite. At higher levels of K-sorb, about 0.5%, the permeability abruptly decreased due to dispersion and vertical movement in silty soils, while it was not changed in fine clayey soils but has the same trend with silty soils. In the plot of 0.3% of K-sorb application, the growth of soybean such as number of pods and stem length etc. increased and the yield also increased about 1.2-1.8 times of control. The optimum amounts of K-sorb were slightly different according to soil texture but estimated from regression curves were about 0.2% to 0.35% of soils in dry weight bases.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.143-150
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• 1983

Red rice (local name "Sore") as a weed has been a serious threat to rice production in direct-seeded rice culture in Ganghwagun, Gyeonggi province. In the Ganghwagun 508 ha out of 1,420 ha in the Samsanmyeon area is infested with red rice. The average lowland rice yield is about 4,300 kg/ha in the Ganghwagun, but the average upland rice yield is about 2,000 kg/ha in infested area. This study was carried out in order to clarify the ecological characteristics of red rice and factors affecting the competitive ability of five red rice varieties, collected from Samsanmyeon in 1981, with rice cultivar. Five varieties-Monggeunsare, Salsare, Ginkaragsare, Galsaegsalsare, Galsaegkaragsare-showed the same morphological characteristics of cultivated Japonica type, Chuncheongbyeo, but red rice tillers more profusely, is taller and lodges more easily than Chucheongbyeo. It shatters easily about 10-15 days after heading date, and at this time the hull is discolored in yellow or dark brown. There are many types of red rice with short or long owns on the spikelet, occasionally with or without own on the spikelet in the same hill, and the grains are short or long. In red reice leaf blast occurs more severely than in cultivated Indica/Japonica type, Teabaegbyeo, particulary serious in Monggeunsare. When red rice invaded in direct-seeded rice, number of panicles of rice became reduced more than other yield components.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.3
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• pp.131-137
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• 1986

Korean lawn, Zoysia japonica STEUD, is the type of a perennial warm-season lawn grass that has a naturally green period during 5 months from May to September. This study was carried out to detect the effects of N-P-K fertilization, regrowth capacity after mowing and chlorophyll contents on prolongation of the green period in Zoysia japonica grasslands. The results obtained are summarized as follows: 1. The effects of nitrogen fertilizer application on Zoysia japonica grasslands were affected on regrowth capacity after mowing, green color of leaf canopies and chlorophyll contents, respectively. 2. A the experimental plots which applied 45g/$m^2$/10 weeks of $N_3$ fertilizer, there were high significant effects on prolongation of the green period and the plots of phosphorus and potassium had additive effects. 3. Prolongation of the green period to the last ten days of October was obviously possible by slow degrees in proportion to increment of N-P-K fertilization. 4. However, it is interpreted that more prolongation of the green period is impossible with N-P-K fertilization and irrigation treatments, unless the intermediate turfgrasses between $C_3$ and $C_4$ plants must be found and bred.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.15-22
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• 2017

Application of organic resources to agricultural land can increase crop yield by improving soil characteristics. The objective of this study was to evaluate effect of crop yield and soil physical properties including aggregate stability to application of organic resources in upland. The soybean was cultivated in a sandy loam field and a clay loam field located at Suwon and a sandy loam field located at Pyeongchang. The organic resources used in this study were rice straw compost (RSC), composted pig manure with sawdust (CPIG), composted poultry manure with sawdust (CPM), and cocopeat applied before sowing crop. Application rate of organic resources was determined based on carbon content and water content. The inorganic fertilizers were applied based on soil testing. In addition, the decomposition of RSC, CPIG, and cocopeat was characterized by isothermal incubation with sandy loam soil. The decomposition rate was highest for RSC followed by CPIG and cocopeat. Organic resource application increased yield of soybean, which effect was greater in clay loam than in sandy loam. In addition, increase in gas phase proportion by organic resource application was distinct in clay loam soil compared with sandy loam soil. In terms of aggregate stability, increasing effect was more obvious in sandy loam soils than in a clay loam soil. The highest yield was observed in RSC treatment plots for all the fields. Improvement of soybean yield and soil physical characteristics by cocopeat was not as much as that of the other organic resources. The results implied that RSC could be recommended for promoting aggregate stability and crop yield in upland cultivation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1219-1225
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• 2005

This study was carried out to investigate the effects of preheating temperature on the properties of the Korean traditional pepper pickle. In experimental groups, the pepper was heated in the warm water at 40, 60, 80$^{\circ}C$ for 10 minutes while the control group was not heated. The contents of chlorophyll and vitamin C in treated pepper were evaluated. The contents of chlorophyll were 30.96$\∼$31.13 mg$\%$ at the initial stage of 0 day and 0.76$\∼$2.34 mg$\%$ for 60 days of storage. The vitamin C contents were increased until storage 6 days and then were decreased. Pickles treated at 60$^{\circ}C$ showed the highest score on hardness after 60 days of storage followed by 40$^{\circ}C$>no-heat treatment (NH)>80$^{\circ}C$. The yellowness on the surface of brined pepper peels was increased with preheating temperature increased. Activities of pectinesterase were the highest at 60$^{\circ}C$ followed by 40$^{\circ}C$>80$^{\circ}C$>NH treated. Activities of polygalacturonase were lower than that of NH group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.343-349
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• 2011

The chemical composition and antioxidative activity of kiwifruit varieties in Jeju, such as Jecy Gold (Actinidia chinensis var. 'Jecy Gold'), Halla Gold (A. chinensis var. 'Halla Gold'), Jecy Sweet (A. deliciosa var. 'Jecy Sweet') and Hwabuk 94 (A. deliciosa var. 'Hwabuk 94') were investigated. The crude protein, crude lipid, and pH showed no differences among variety and maturity whereas the moisture contents showed differences among the variety and maturity. Jecy Sweet in mature stage showed the highest values in soluble solid, crude protein, crude lipid, and crude ash. The changes in chemical components of kiwifruit by maturity stage were as follows: during ripening, the glucose and the fructose contents increased considerably with the decrease of sucrose content. Potassium, phosphorus, sodium, and magnesium were estimated as the major minerals in kiwifruit and Jecy Sweet contained the highest amounts of potassium and magnesium. At maturity stage, ascorbic, malic and lactic acid were increased with the decrease of citric acid content. The polyphenol contents were 26.81~56.10 ${\mu}g/g$ and 8.64~26.45 ${\mu}g/g$, respectively, in immature and mature fruits. During ripening, the polyphenol content was decreased. The DPPH radical scavenging activity of methanol extracts were 84.47~89.37% and 43.94~76.96% at 500 ppm, respectively, in immature and mature fruits. The immature varieties of kiwifruit have a high DPPH radical scavenging activity. Therefore the chemical composition and physiological activity of kiwifruit was affected by variety and maturity.