• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.153-161
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• 1999

No-till direct-sown rice-wheat relaying cropping system has major advantages such as labor and cost saving by eliminating tillage and preparation of seed bed and transplanting. In this system, rice sowing was done simultaneously wheat harvesting. A paddy field experiment was conducted to evaluate effects of no-till years on soil microbial changes and soil physico-chemical characteristics with rice growth and development. Chemical fertilizers and agricultrual chemicals was not applied in no-till system. As the year in no-till direct-sown system the air permeability was increased and after water submerging soluble nitrogen was released Aerobic microbial-n was highest in May and then decreased after water irrigation. The population of aerobic soil microorganisms were steeply decreased after water submerging Soil microorganisms was decreased with the increased the soil depth. A month was needed for the seedling establishment in a no-tillage rice-wheat cropping system. Increased cropping years improved leaf greenness and leaf area index(LAI). But stomatal conductance(Gc) was higher in conventional cultivation system than no-till system. Stomatal conductance at panicle initiation stage was increased higher in conventional condition of leaves but the difference between conventional and no-till system was increased at heading stage. In no-till 4 years condition rice grain yield was spikelet numbers per panicle.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.436-446
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• 2020

In this study, we verified the effects of organic amendment application based on soil testing in potato cultivation. The application rate of organic amendments was determined based on the inorganicization rate of nitrogen, phosphoric acid, and potassium in the organic amendments. There was no significant difference in the length, stalk number, stalk diameter, and leaf color of potato plants under organic amendment application compared with those under chemical fertilization. The quantity of potato tubers and yield of marketable tubers under organic amendment application were higher than those under chemical fertilization. The top fresh weight and top-to-root ratio were the highest under organic amendment application, followed by those under chemical fertilization and the control. The inorganic nitrogen content in the leaves and stems of potato plants was the highest under chemical fertilization. There was no difference in the phosphoric acid content between the potatoes under chemical fertilization and those under organic amendment application. The potassium content in potatoes was higher under chemical fertilization than that under organic amendment application. While the change trend of inorganic nitrogen content in the roots was similar to that in the leaves and stems, the potatoes under organic amendment application, with the highest yield, showed the highest dry weight. The tuber weight showed a positive correlation with plant length, stalk number, and stalk diameter. The higher the weight of the tuber, the higher the weight of the marketable tuber, and the higher the top fresh weight, the higher the yield. Therefore, to increase yield, it is necessary to supply nutrients to improve the top fresh weight to the optimal level. There was no difference in the utilization efficiency of nitrogen and potassium between the potatoes under chemical fertilization and those under organic amendment application. The utilization efficiency of phosphoric acid was increased by 0.1% in potatoes under organic amendment application compared with that under other treatments. Regarding soil chemistry after harvest, the soils under organic amendment application showed a higher electrical conductivity and higher nitrogen and phosphoric acid content than those under other treatments. Therefore, the organic amendment method used in this study can be an alternative to chemical fertilization. It is also advantageous for the cultivation of subsequent crops in potato fields.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.1
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• pp.45-55
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• 1987

For some basic information in tobacco breeding, the modes of inheritance and heritabilities for the twelve agronomic and chemical characters were estimated in the study of eight varieties partial diallel set. Additive gene actions were significant for all characters except total nitrogen content and dominance gene effects were also significant for all characters. Yield, number of leaves per plant, leaf length and leaf shape index were inherited as partial dominance, and overdominance was detected for plant height, stem diameter, internode length, total alkaloid, total nitrogen and total sugar content. Dominant gene showed increasing effects in yield, plant height, stem diameter, internode length, leaf width and total sugar content, but showed decreasing effects in the other characters. The broad heritability was very high for all characters. and the narrow heritability was high in days to flower and yield, but low in internode length, total alkaloid, total nitrogen and total sugar content.

• Advances in nano research
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• v.2 no.3
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• pp.135-145
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• 2014

Nanomaterials synthesized by natural bioresources such as microorganisms, animals and plants in nature can also be synthesized in laboratories even on large scale. This is considered as an attractive prospect for eco-friendly or so-called green synthesis. Development of eco-friendly synthesis of biocompatible nanoparticles and their potential biomedical applications introduces the concept of nanobiotechnology. The lower cost and lesser side effects as compare to chemical methods of synthesis are the main advantages of biosynthesis. This review article demonstrates the role of various biological resources e.g. bacteria, fungi, actinomycetes, plant leaves, fruits and honey as well as animal tissues for the synthesis of nanoparticles mainly gold and silver with an overview of their potential applications.

• YAKHAK HOEJI
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• v.17 no.1
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• pp.21-26
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• 1973

The constituents of Korean cannabis were studied comparatively with foreign orgins. Especially, tetrahydrocannabinol(THC), the active constituents of cannabis were analyzed by the technique of thin layer chromatography and colorimetry. The results are as follows ; (1) THC content in Korean cannabis is comparatively higher than that in foreign samples. (2) THC is contained most abundantly in male flowers, abundantly in female tops and leaves and some in barks. (3) There is a tendency that the THC content increase gradually with growth of plants, being highest during unripe nad decrease with maturity of the tops. (4) Korean cannabis contains THC, cannabinol, cannabidiol, cannabidiolic acid and other cannandiolic compounds. Distribution of chemical components of Korean cannabis, compared with those of foreign ones, is remarkably different. (5) The THC content of Spanish cannabis cultivated tentatively in Korea is similar to that of Korean cannabis.

• Natural Product Sciences
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• v.2 no.2
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• pp.106-114
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• 1996

Four polymethoxyfavones were isolated from the leaves of Citrus deliciosa, three of which (nobiletin, 5-O-demethylnobiletin, and tangeritin) are bioactive. The fourth (7,4'-dihydroxy-5,6,8,3'-tetramethoxyflavone) is reported for the first time in the genus Citrus and is a potential chemotaxonomic marker. The structures of these flavones were confirmed by analysing their spectral data and comparison with similar compounds. The previously reported $^{13}C$ NMR assignment of 5-O-demethylnobiletin has been revised on the basis of 2D NMR experiments (HETCOR, COSY, and COLOC). The chemotaxonomic value of the present finding is verified.

• Agricultural and Biosystems Engineering
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• v.1 no.1
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• pp.16-21
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• 2000

Measurement of spray deposit is necessary for evaluation of a chemical application technology. However it is not easy and time consuming. A simple method for measuring the deposition amount of spray using a tracer and a spectrophotometer was developed. Various materials were tested to determine an adequate tracer. Food dye was selected as a tracer, because it was cheep and easily treatable. Using NIRS(Near Infrared Reflection Spectrophotometer), a regression curves between maximum absorbance of a solution and concentration of the tracer were obtained. Yellow food dye solution showed a peak of spectrum at 452 nm, and absorbance of peak showed a tendency to increase as concentration increased. Green or pink food dye were tested and judged to be good tracers. However, tracer concentration should not exceed certain limits in order to measure maximum absorption. Using spraying liquid with known tracer concentration and known amount of washing liquid, spray deposit amount on real targets on leaves could be estimated at less than 13% error level.

• Korean Journal of Pharmacognosy
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• v.21 no.2
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• pp.111-120
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• 1990

Five biflavones and sevenflavonolglycosideswereisolatedfromtheleaves of Ginkgo biloba. They were sciadopitysin(1), ginkgetin(2), isoginkgetin(3), bilobetin(4), amentoflavone(5), kaempferol 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](6), quercetin 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](8), rutinosides of kaempferol(7), isorhamnetin(9), quercetin(10), laricitrin(11), and kaempferol 3-O-($2',6'-{\alpha}-_L-dirhamnopyranosyl-{\beta}-_{D}-glucopyranoside$)(12). The structures were established by spectroscopic and chemical methods.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.3
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• pp.159-169
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• 1994

This paper describes the process of acidic precipitation from the atmosphere to the ground water, The net deposition of wet precipitation to the ground surface is obtained by subtracting the interception loss due to plant leaves and evaporation from the amount of total precipitation. As the water immerses through the vegetation and the different soil layers the various chemical reactions take place. The relationship between the acidic precipitation by increasing industrial emissions and the soil acidification mechanism is discussed. The report focuses on the buffering action that involves the proton budget in soil and rocks. Based on the soil constituents, the six buffer ranges of the soil are classified and each buffering process is illustrated. In addition, the Possibility of the contamination of drinking-water reservoirs by continuous acid burden is emphasized.

• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1109-1113
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• 2004

A new triterpene (1) and six known pentacyclic terpenoids (2-7) were isolated from the methanol extract of the dried leaves from Mallotus apelta. Based on the spectral and chemical evidence, their structures were determined to be 3$\alpha$-hydroxyhop-22(29)-ene (1), hennadiol (2), friedelin (3), friedelanol (4), epifriedelanol (5), taraxerone (6), and epitaraxerol (7).