• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.429-437
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• 2019

This study was conducted to examine the effect of humidification and shading during cutting propagation on growth and development of strawberry (Fragaria x ananassa Duch.) 'Maehyang' plants at a propagation stage. The runner cuttings were stuck on Nov. 23, 2017 in propagation benches set in a Venlo-type glasshouse. Four shading treatments, no shading (control, C), 55% shading with white lawn (W55), 55% black shading net (B55), or 100% black plastic film (B100) with either an intermittent fog system (H) or without fog system. The shading and fog systems were removed 2 weeks after sticking of strawberry cuttings. A nutrient solution for strawberry, which was developed by Yamazaki, was supplied once a day with electrical conductivity (EC) $1.6dS{\cdot}m^{-1}$ and pH 5.8. Growth parameters such as plant height, longest root, crown diameter, leaf chlorophyll, leaf area and fresh and dry weight were measured at 7 days and 26 days after sticking. There was no significant difference in growth of above-aerial part of strawberry. The overall growth of the strawberry roots was better grew by providing fog than that not provide fog. The root fresh weight and root dry weight after 26 days after sticking of strawberry cutting was the best in the treatment that provided fog system without shading (CH). The longest root after 26 days after sticking of strawberry cutting was the best in the treatments that provided fog system with either 55% white lawn (W55H) and 55% black shading net (B55H). These results suggest that morphogenesis of these plants were affected by humidification and shading types. In a broader perspective, these results can be used to optimize studies of other crops grown from cuttings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.225-233
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• 2019

This study was conduct to investigate the effect of mixed seed sowing and flour blending on the uniformity of flour quality of Korean domestic wheat. Two wheat varieties (Keumkang and Baegjoong) were selected for sowing mixed seeds, and their growth characteristics and flour quality were analyzed. Quality of flour blending with the same varieties was also evaluated. The ratios for mixed seed sowing and flour blending were from 0 to 100% with a 10% increase of interval for each treatment. On increasing the portion of Baegjoong in mixed seed sowing, the heading time was a little delayed, however, yield increased. The results of the flour quality showed lower damaged starch content and sodium carbonate SRC (solvent retention capacity) value for Keumkang than for Baegjoong. Protein quantity by protein content and quality by SDSS (Sodium Dodecyle Sulfate-Sedimentation) volume, lactic acid SRC, and mixograph pattern of Keumkang were superior to those of Baegjoong. Compared with mixed seed sowing, overall quality characteristics of flours with different ratios showed predictable and proportional change by flour blending. This demonstrated the successful application of flour blending, compared with mixed seed sowing, for improving the uniformity of flour quality.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.480-485
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• 2019

The present study was conducted to compare antioxidant capacities of protein hydrolysates from four different edible insects (Protaetia brevitarsis larvae, Allomyrina dichotoma larvae, Gryllus bimaculatus imago, and Tenebrio molitor larvae) which have recently been registered as food varieties in Korea. Protein hydrolysates were prepared from each insect using enzymatic hydrolysis using alcalase, and were then separated into a fraction containing ${\leq}3kDa$. According to $RC_{50}$ values and trolox equivalent antioxidant capacity results obtained from five different antioxidant analyses, the Gryllus bimaculatus (GB) hydrolysate showed relatively high levels of antioxidant capacity and, in particular, the GB hydrolysate showed considerably strong antioxidant activities in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and in ferric reducing antioxidant power (FRAP) assays. The GB hydrolysate also showed the strongest inhibitory effect on peroxidation of linoleic acid, and its rate of inhibition at $100{\mu}g/mL$ on day 3 of treatment was 60.26%. These results suggest that protein hydrolysates from edible insects including GB represent potential sources of natural antioxidants.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.864-873
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• 1995

Amorphous $Fe_{73.5}Cu_{1}Nb_{3}Si_{16.5}B_{6}$ ribbons were annealed for different time at $500^{\circ}C$ and $552^{\circ}C$, just before and after the exothermic reaction in DSC curve. The development of nanocrystalline phase was investigated by means of $M\"{o}ssbsuer$ spectroscopy. The crystalline phase consists mainly of $DO_{3}Fe-Si$. Though slight in amount (5%), another ferromagnetic phase which could be presumed $t-Fe_{3}B$ was detected Si content of $DO_{3}Fe-Si$, Si/(Fe+Si), was 0.218 under the heat treatment at $500^{\circ}C$ for 60 min and 0.222 at $552^{\circ}C$ for 10 min. Since then both of those values decreased with time until 120 min and finally these two values remained constant at 0.210. The variation in Si content with annealing time results in the variation in the hyperfine field and the isomer shift. The increase in the mean hyperfine fields and the decrease in the mean isomer shifts of Fe-Si are caused by the increase in Si content. The volume fractions of residual amorphous phase rapidly decrease during the early stage of annealing and come nearer to saturation after 120 min both at $500^{\circ}C$ and $552^{\circ}C$. The decrease in the mean hyperfine field of residual amorphous. in spite of slight changes in the volume fractions of Fe-Si and of residual amorphous after 120 min. is caused by the increase in the content of Nb and B in residual amorphous phase. The saturated volume fraction of the crystalline phase was 81% for $500^{\circ}C$ (180 min) and 77% for $552^{\circ}C$ (960 min), different from expectation.

• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.263-270
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• 2015

To reduce the injury by continuous cropping system of tomato cultivation, green manure crops (GMCs) such as hairy vetch and rye were applied, Nutrient contributions of N, P₂O₅, K₂O, CaO, and MgO in hairy vetch were 26.2, 5.8, 10.2, 6.6, and 1.5 ㎏/10a, respectively. Nutrient contributions of N, P₂O₅, K₂O, CaO, and MgO in rye were 9.1, 4.2, 11.8, 3.8, and 3.1 ㎏/10a, respectively. After incorporation of GMCs into soil, bulk density in soil with GMCs was lower than that in soil without GMCs (control). In soil after incorporation of GMCs, pH was not different in all treatment conditions, and ranged from 6.37~6.52. EC in soil after incorporation of GMCs was lower than that in soil without GMCs. The OM, T-N, and avail. P₂O₅ contents in soil with GMCs were higher than those in soil without GMCs. The tomato growths were increased in the rotational cropping system (RCS) as compared to continuous cropping system (control and without NPK). Also the density of Pseudomonas corrugata in soil with GMCs was lower than that in soil without GMCs (control). This study suggest that the RCS using GMCs showed lower disease outbreak density in soil for tomato cultivation as compared to RCS without GMCs. Especially, the GMCs was good effect for reduction of continuous cropping injury of tomato.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1150-1157
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• 2011

Streptomyces sampsonii KK1024 having strong chitinolytic activity was isolated from crab-shell rich soil at Muan, Jeolanamdo. The KK1024 produced chitinase, protease, gelatinase and lipase. When 50% of KK1024 culture broth was treated to juveniles and eggs of root-knot nematode, juvenile mortality at 3 days was 81.67% and egg hatch rate at 5 days was 2.00%. When $183.7{\mu}g\;mL^{-1}$ of crude enzyme produced by KK1024 was treated, juvenile mortality at 3 days was 96.00% and egg hatch rate at 5 days was 5.33%. At 1% of butanol extract from KK1024, juvenile mortality was highest with 90.00% and egg hatch rate was lowest with 0%. The comparison of the effect of KK1024 culture broth with only medium, synthetic fertilizer, and commercial nematicide on tomato growth and nematode infection was examined in pot trials. KK1024 culture broth showed lower number of egg mass and gall in plant, and population of juveniles in soil compared with only medium and synthetic fertilizer treatment, but not in commercial nematicide. However, the highest shoot weight and length was discovered in KK1024 culture broth. These results suggest that Streptomyces sampsonii KK1024 producing lytic enzymes and nematicidal compounds can be one of candidates for biocontrol agents against root-knot nematodes.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1071-1079
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• 2011

In this study, coal combustion ash (CCA) was evaluated for its stabilization effect on acidic mine waste with column experiment. Total of six treatments were installed depending on mixing ratio between coal wastes and CCA (0, 20, 40%) and mixing method (completely mixing and layered). Artificial acidic rain (pH 5.6) was used for feeding solution with flow rate of $0.05mL\;min^{-1}$. Result showed that higher pH of leachate was observed as more CCA was mixed. The highest pH in leachate was measured when 40% of CCA was mixed with coal waste (pH of 5.8). Also, complete mixing with CCA and coal waste was more effective to increase the pH of leachate than layered treatment. Regarding the reduction of soluble Fe amount, the highest efficiency (78%) was observed when 20% of coal ash was completely mixed with mine waste. Based on those result, optimum mixing ratio of coal ash with mine waste can be ranged 20-40% depending on environmental circumstances in the field.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.981-986
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• 2010

This study was carried out to investigate the effects of fertilizer and organic resource annual dressing for 30 years of Jeonbug series (silt loam) on soil properties and rice N uptake in paddy field soil. In the study field, treatments including control (NPK), NPK+rice straw, NPK+rice straw compost and nitrogen fertilization levels at 0, 100, 150, 200, 250 kg $ha^{-1}$ have been imposed for 30 years. Soil hardness and bulk density decreased from 15.7 mm and 1.381 Mg $m^{-3}$ in the control to 12.5 mm and 1.244 Mg $m^{-3}$ in NPK+rice straw compost treatment, respectively, indicating improvement of soil physical conditions such as porosity. Co-application of straw compost with NPK also result in a better chemical properties than NPK alone as it increased available phosphate (from 96 to 133 mg $kg^{-1}$), available silicate (from 81 to 116 mg $kg^{-1}$), and cation exchange capacity (from 9.8 to 11.4 $cmol_c\;kg^{-1}$). Soil organic matter concentration of top soil (0 to 7.5 cm in depth) was higher in NPK+rice straw and NPK+rice straw compost than in control. Fertilizer N uptake amount was much higher in NPK+rice straw (nitrogen fertilization level; 250 kg $ha^{-1}$) and NPK+rice straw compost (nitrogen fertilization levels; 200, 250 kg $ha^{-1}$) plots compared to the control (nitrogen fertilization level; 100 kg $ha^{-1}$) plot. Nitrogen use efficiency was showed significantly high in the NPK+rice straw compost (nitrogen fertilization levels; 100, 150 kg $ha^{-1}$) plot compared to the control (nitrogen fertilization level; 100 kg $ha^{-1}$) plot. Therefore, it was suggested that application of organic inputs is helpful in improving soil fertility and physical conditions and thus in N uptake.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.85-94
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• 2007

To determine the influence of food waste compost (FWC) application on paddy soil, FWC was applied to the paddy soil and then compared with farmer's practice as to the effects on rice and soil environment. Initially, pig manure compost (PMC) had high content of phosphorus ($15g\;kg^{-1}$) and potassium ($23g\;kg^{-1}$), while FWC had high content of total nitrogen ($13g\;kg^{-1}$) and salinity ($18.5g\;kg^{-1}$). Comparison was also made between chemical fertilizer and FWC use as a trial in the paddy field under the clay loam and sandy loam soil. In the panicle formation stage, chemical fertilizer application was proper in clay loam while PMC application was proper in sandy loam. However, chemical fertilizer produced higher yield compared to compost treatment, both on clay loam and sandy loam with 20~25% and 17~19%, respectively. The lower yield in sandy loam maybe due to slow mineralization of compost such that the crop did not effectively use it. Organic matter content in paddy soil after experiment was higher in FWC and PMC plots compared to that in chemical fertilizer plots. But the other soil properties were comparable. Therefore, the FWC compost had little effect on soil when it use as a trial in paddy field. Likewise, after the application of FWC as a trial, analysis of nitrate nitrogen and ammonium nitrogen in the surface water and 60 cm depth of paddy soil water nine days after planting was done. Results revealed that concentration of ammonium nitrogen was similar to irrigation water while nitrate nitrogen concentration was not detected, and hence did not contribute to water pollution. It is concluded that the application of FWC in the paddy field had not affected on environmental pollution in the paddy field. But its use as compost during rice culture reduced yield quantity. Such study should include selection of compost material, amount and method of compost application.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.447-453
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• 2007

With a broad objective for the development of microbial based fertilizers, a total of 373 strains were isolated from rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass. The efficacy of the isolates to augument overall plant growth was evaluated. After screening for their plant growth promotion and antagonistic properties in vitro efficient strains were further selected. The most efficient strains was characterized by 16S rRNA gene sequences and biochemical techniques and was designated as Bacillus subtilis S37-2. The strains facilitated plant growth and inhibited the plant phathogenic fungi such as Fusarium oxysporum (KACC 40037, Rhizoctonia solani (KACC 40140), and Sclerotinia sclerotiorum (KACC 40457). Pot based bioassay using lettuce as test plant was conducted by inoculating suspension ($10^5$ to $10^8cells\;mL^{-1}$) of B. subtilis S37-2 to the rhizosphere of lettuce cultivated in soil pots. Compared with non-inoculated pots, marked increase in leaf (42.3%) and root mass (48.7%) was observed in the inoculation group where the 50ml of cell mixture ($8.7{\times}10^8cells\;ml^{-1}$) was applied to the rhizosphere of letuce either once or twice. Antagonistic effects of B. subtilis S37-2 strain on S. sclerotiorum (KACC 40457) were tested. All the tested lettuce plants perished after 9 days in treatment containing only S. sclerotiorum, but only 17% of lettuce was perished in the inoculation plot. B. subtilis grew well in the TSB culture medium. The isolates grew better in yeast extracts than peptone and tryptone as nitrogen source. The growth rate was 2~4 times greater at $37^{\circ}C$ as compared with $30^{\circ}C$ incubation temperature. B. subitlis S37-2 produced $0.1{\mu}g\;ml^{-1}$ of IAA (indole 3-acetic acid) in the TSB medium containing L-tryptophan($20mg\;L^{-1}$) in 24 hours.