• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.6-12
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• 1992

To study the effects of irrigation on the mulberry, 3 experiments were conducted. In experiment 1, four treatments, conventional (no irregation), drip irrigation, fertigation and fertigation with 20% extra fertilizer were examined. Irrigation hose was hurried at 20cm depth under the surface (Experiment 1). Water potential was controled at 0.1, 0.2, 0.5 and 1.0 bar to understand the optimum irrigation potential under rain-block system with plastic film hose(experiment 2). Five leading mulberry varieties, Cheongilppong, Youngcheonppong, Suseongppong, Kaeryangppong and Shinilppong were examined for irrigation response(experiment 3). Fertigation and fertigation with extra fefilizer increased yield by 22%, repectively compared with conventional. Irrigation increased by 8%, but with no significance statistically compared with the conventional. Irrigation, especially fertigation increased water content, P$_2$O$_{5}$, $K_2$O and CaO in leaves, suggested improving leaf quality in fall. Fertigation increased available P$_2$O$_{5}$ content in the sub-soil. More root distribution showed at the sub-soil in fertigation. Weed did not occured in fertigation due to sub-soil fertilization, whereas the conventional received surface fertilization showed 931kg/10 a weed in fresh weight. No effect showed at the 20% extra fertilizer than the conventional amount Maximun yield showed at the 0.5 bar water potential. Irrigation increased yield by 22-25% with Cheongilppong and Yongcheonppong, and by 9-13% with Suseongppong, Shinilppong and Kaeryangppong.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.270-274
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• 1996

To estimate the suitable method of phosphorus application in puddled-soil drill seeding of rice, available phosphorus, appearance of algal water bloom, and rice yield were investigated in paddy soil of Honam area from 1994 to 1995. Available phosphorus content with different regions was the highest in the east-west inland region of Noryeong mountain range and the inland region of Honam area and it was the lowest in the Charyeong south plains region. Available phosphorus content was the highest in the alluvial plains. and it was the lowest in dilluvial terrace. Frations of phosphorus in Jeonbug series were high in the order of Ca-P, Fe-P, and Al-P, respectively. Algal water bloom occurred highly in 100% and 70% basal applications before seeding, and slightly in no-fertilizer and 100% application of 3-leaf stage in puddled-soil drill seeding of rice. Suitable amount of phosphorus application was 21kg/ha in the single cropping paddy field of Fluvio-marine plain, and rice yield was increased 6% at 50% basal application.

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.117-124
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• 2003

This study was designed to test the effect of Korean traditional tea materials on oxygen-free radical metabolism in lead (Pb) -administered rats. Male rats were divided into normal, Pb-control (Pb-Con) and Pb-water extract of green tea (Camellia sinensis; GT) , persimmon leaf (Diospyros kaki; PL) , safflower seed (Carhamus tinctorius: SS) , Du-Zhong (Eucommia ulmoides; EU) groups, respectively. Pb intoxication was induced by administration of lead acetate (25 mg/kg. B.W., oral) weekly. The extract was administered based on 1.26 g of raw material/kg B.W./day for 4 weeks. When the GT, PL, SS and EU were supplemented to the Pb-administered rats, hepatic lipid peroxide levels were significantly lower compared to the Pb-Con group. Hepatic cytochrom P-450 content and aminopyrine N-demethylase activity was lower in the Pb-Con group than in the normal group, whereas xanthine oxidase activity was significantly elevated in Pb-administered rats. The water extract of GT, PL, SS and EU supplementation attenuated changes in enzyme activities generating reactive oxygen species in the liver. Hepatic superoxide dismutase, catalase and glucose 6-phosphate dehydrogenase activities were significantly higher in the Pb-Con group than in the normal group, while monoamine oxidase activity also tended to increase in the Pb-administered rats. However, glutathione peroxidase and glutathione S-transferase activities, and glutathione content significantly decreased through Pb intoxication. The supplementation of GT, PL, SS and EU induced alleviation changes of hepatic antioxidant enzyme activity.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.1-4
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• 1980

The Chemical components of Abies koreana Wilson grown in Korea were analized. The results obtained were summarized as follows. 1. The ash content is ca 0.56% on the average, and of the range is 0.33 to 0.76%. 2. The cold water extractive content is ca 8.76% on the average and of the range is 5.55 to 12.5%. 3. The hot water extractive content is ca 10.16% on the average and of the range is 4.80 to 13.65%. 4. Basic extractive content is ca 14.60% on the average and of the range is 5.51 to 25.44%. 5. The alcohol benzol soluble fraction is ca 4. 23% and of the range is 2.94 to 5.44%. 6. The holocellulose content is ca 76.49% on the average and of the range is 73.68% to 79.10%. 7. The cellulose content is ca 56.30% on the average and of the range is 46.02% to 61. 33%. The cellulose contains 78.54% ${\alpha}$-cellulose, 7.66% ${\beta}$-cellulose and 14.04% ${\gamma}$-cellulose respectively. 8. The Klason lignin content is ca 25.03% on the average and of the range is 22.5 to 27.0%. In conclusion, ash content is comparable to the other needle leaf trees. It has 76.49% in holocellulose content which is comparable value to the Pinus densiflora's. It has lower value than the Pinus densiffora in pentosan and lignin content. Having not resin cannal in xylem and long tracheid, this wood could be usable industrial material.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.745-756
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• 2013

This study was carried out to suggest an experimental base to maintain the sustainability of extensive green roof as considering moisture demand by the type of the green roof plant before construction. The changes of soil moisture content, chlorophyll content, coverage of Sedum kamtschaticum and Dianthus chinensis var. senperflorens in two type of perlite soil and mix soil, were investigated under the condition of no rainfall and no irrigation during one month. The result shows that with the increase of stress time, soil moisture content and chlorophyll content on leaf were in a downward trend; After 30 days, Soil moisture content were lowest in 10 cm depth perlite soil system planted Dianthus chinensis. and 20 cm depth mix soil system planted Sedum kamtschaticum had the highest soil moisture. Generally soil moisture contents of soil system planted Dianthus chinensis var. senperflorens were lower than that of soil system planted Sedum kamtschaticum. In 10 cm depth soil system, state of plant growth was better than 20 cm depth soil system both perlite soil and mix soil type. It can be confirmed.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.2
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• pp.105-114
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• 2018

The aim of this study was to evaluate the change of phenolic compounds after phosphite treatment on Cheorwon onion. Onion is a perennial plant belonging to the lily family. It is native to Persia of Southwest Asia. It is widely cultivated in the temperate regions of the world. Onion is a good name for the 'Okchong' to drop blood cholesterol and cardiovascular blood flow to increase the prevention of adult diseases. Cheorwon area is inland, but it has high continental climate due to its high altitude. Therefore it is said that the onion cultivated in this region has higher sugar content and higher taste than onion grown in the southern region. Phosphorus components are particularly important ingredients for promoting muscle development. However, if the phosphoric acid content of the soil part is maintained to a large extent until the harvest, the competition of the nutrients tends to cause decay of the root part. Therefore, it is important to improve the quality and shelf life of onion by inducing nutrient balance by applying foliar fertilization method on the reducing phosphorus at harvest time. In this study, acidity was controlled by diluting phosphorous acid(H₃PO₃) and potassium hydroxide(KOH), followed by leaf surface treatment with phosphite on onion. In this study, the concentration of phosphite was diluted to 500, 1,000, 1,500ppm and sprayed three times over the onion leaves in May 2018 using an atomizer and harvested at the end of June, and the phenolic compounds were analyzed by HPLC. As a result, the content of quercetin, one of the important substances in onion, was phosphite 500ppm(179.70㎍/g), 1,000(150.27), 1,500(105.95). The contents of caffeic acid, p-coumaric acid, ferulic acid, rutin, kaempferol, and sugar content were higher in the treatments than in the control. Therefore, the phosphite does not have a great influence on the growth, but it may play a role as a method of achieving balance with nitrogen in the rainy season by supplying the role of the material catalyst and the water soluble phosphoric acid and the potassium in the influence of the material change.

• The Korean Journal of Ecology
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• v.26 no.6
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• pp.321-326
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• 2003

This study was conducted to investigate and effects of shading treatment on photosynthetic activity of Acanthopanax senticosus. We investigated plant growth, light response curve and A-Ci curve to photosynthesis of A. senticosus at 55%, 75%, and 90% shading treatment. As results, the ratio of above-ground/under-ground biomass was increased at 75% shaded condition and showed highest dry biomass. Under shaded conditions, plants had lower chlorophyll a+b content and a/b ratio and also showed thinner leave. But shaded plants showed higher leaf area and higher total leaf area per a plant. This apparently indicates adapted responses to shaded treatment. Effects of shading treatments on photosynthetic activity were higher in apparent quantum yield, carboxylation efficiency, re-phosphrylation but lower in light compensation point. These results suggested that higher photosynthesis rates in shaded treatments were due to activated carboxylation efficiency. Shading treatment had lower water use efficiency thatn controls but still higher than other tree species.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.139-145
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• 1987

This study was carried out to find out the effects of ammonia gas on the leaf destruction of vegetable crops, and nitrogen contents in their leaves. Radish, chinese cabbage, tomato and cucumber were fumigated with 0.05, 0.1, $0.2mg/{\ell}$ ammonia gas for 2 hrs under different exposure time, light and soil water condition at vegetative growth stage. The results obtained were as follows. The crop damages measured by percentage of leaf destruction were more severe at the night time fumigation than treatment during the day, at the full sun condition than the shading, and at the higher soil water contents. Cucumber plant showed higher resistance to ammonia gas than tomato plant. The chrolophyll contents in leaves of each crops were remarkably decreased by increment of ammonia concentration from $0.05mg/{\ell}$ to $0.2mg/{\ell}$, but the N content in them was increased.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.976-985
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• 2010

In this study, characteristics of dissolved organic matter (DOM) from Lake Paldang and seven other DOM sources (lake plankton, plants, soil, composite, treated sewage) were studied using XAD resin fractionation and 28-day microbial incubation experiment. Distribution patterns of DOM-fractions, which include hydrophilic acids (HiA), hydrophilic bases (HiB), hydrophilic neutrals (HiN), hydrophobic acids (HoA), hydrophobic neutrals (HoN) and the extent of DOM biodegradation (i.e., biodegradability) were different depending on the origins of the DOM samples. The DOM distribution pattern and the biodegradability were found to be effective for distinguishing the different DOM sources. The biodegradability (%) had negative correlations with the content (%) of hydrophobic fractions (Ho) and specific UV absorbance of DOM, which indicate that the Ho fractions contain more aromatic carbon structures and relatively stable during biodegradation, irrespective of the sources. To gain additional insight into the microbial transformation of the DOM, we also investigated the changes in the fraction's distribution for plankton, leaf litter and composite samples after the incubation. The results showed that biodegradation of hydrophilic fraction (Hi) causes an increase in the proportion of Ho (HoA, HoN), while biodegradation of HoA increases the HoN production.

• Journal of Forest and Environmental Science
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• v.33 no.2
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• pp.97-104
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• 2017

Investigation was carried out on response of Tetrapleura tetraptera (Schum. and Thonn.) to soil, water and light with the view of its domestication and introduction to different ecological regions. The experiment was arranged in a factorial experiment of $3{\times}3{\times}3$ in a completely randomized design (CRD) with three replicates. The factors were: soil textural class (Loamy sand, Sand and Sandy clay loam), watering regime (daily, twice a week and once a week) and light intensity (100%, 75% and 50%). Soil textural classes had significant influence on collar diameter, stem height, number of leaflets, root/shoot ratio and relative growth rate of Tetrapleura seedlings. Seedlings grown on loamy sand recorded the highest mean value- 2.28 mm for collar diameter, stem height- 12.9 cm, number of leaflets- 19.9, chlorophyll b- $0.34mg\;mL^{-1}$, leaf relative water content- 27.4% and relative growth rate- $0.037mg\;g^{-1}\;day^{-1}$. Watering regime had significant influence on the collar diameter of Tetrapleura. Seedlings watered daily recorded the highest mean value- 2.25 mm for collar diameter. Light intensity significantly influenced collar diameter and root/shoot ratio. Seedlings exposed to 100% light intensity recorded higher mean value for collar diameter- 2.28 mm and root/shoot ratio- 1.481 cm. The interaction between soil textural class and light intensity significantly affected collar diameter, stem height and number of leaflets. Higher mean value for collar diameter (2.47 mm) stem height (13.25 cm) and number of leaflets (21.16) were recorded while the interaction between soil textural class, light intensity and watering regime was significant for only number of leaflets. Tetrapleura exhibited some level of tolerance to different soil texture, drought and light intensity. Therefore, Tetrapleura has the potentials to be raised in different ecological zones characterized by difference in soil, rainfall and amount of sunshine.