• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.106-106
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• 2022

An appropriate amount of nitrogen fertilizer input during rice cultivation is essential for rice growth, quality control, and reduction of greenhouse gases in paddy fields. Therefore, it is necessary to develop a technology that can check whether an appropriate amount of fertilizer is applied in paddy fields. In this study, we tried to derive a method for diagnosing nitrogen fertilization level using spectroscopic diagnosis, physiological analysis, and molecular indicator genes. Nitrogen fertilization treatment was performed in a greenhouse by dividing into five treatment conditions: no fertilization (N0), low fertilization (N0.5), standard fertilization (N1.0), excessive fertilization (N1.5), and double fertilization (N2.0), respectively. Growth characteristics analysis was investigated by nitrogen fertilization conditions and growth stages, and the height of the canopy was analyzed using a laser scanner. Physiological and spectroscopic analyses were performed by analyzing chlorophyll and sugar contents and measuring SPAD and leaf spectrometer on rice leaves. In addition, real-time PCR experiment was performed to check the relative expression levels of several known nitrogen metabolism related genes. These results suggest that spectroscopic techniques can be helpful in diagnosing the level of nitrogen fertilization in rice paddy fields.

• 한국작물학회지
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• 제44권2호
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• 한국토양비료학회지
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• 제48권1호
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• pp.30-35
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• 2015

This study was conducted to investigate investigated the effect of nitrogen fertilizer on nitrate concentration in soil solution and to determine the relationship between yield and nitrate concentration in soil solution for cucumber cultivation under plastic film house. Nitrogen as urea was applied at rates of 0, 120, 240, 360, and $480kg\;N\;ha^{-1}$ as an additional fertilizer by trickle irrigation during cucumber cultivation. Monitoring of nitrate concentration in soil solution was investigated using porous cups at 25 cm depth under soil surface. Nitrate concentration in soil solution increased with increasing the rate of additional nitrogen. Correlation coefficient between EC value and nitrate concentration was positive in soil and soil solution (p<0.05). An additional nitrogen of about $300kg\;ha^{-1}$ was shown the highest yield of cucumber, and improved yield by 5% compared to N recommendation of $240kg\;N\;ha^{-1}$. The highest yield was determined at nitrate concentration of $82mg\;L^{-1}$ in soil solution by regression equation ($Y=74.2+0.73X+0.000504X^2$, $R^2=0.629^*$). These results means indicate that nitrate concentration in soil solution would be useful method to rapid determination for additional nitrogen during cucumber cultivation under plastic film house.

• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1159-1163
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• 2008

Data of 42 balance measurements from dry and lactating Holstein cows and blood and urine samples from 24 Japanese Black cows were collected to evaluate the potential for predicting urinary nitrogen (N) excretion from plasma urea nitrogen (PUN). Similar positive correlations were obtained between N intake and apparent N absorption in dry and lactating cows. The regression equations of N intake on urinary N excretion varied in dry and lactating cows, and the difference of urinary N excretion between dry and lactating cows was due to the N secretion into milk. Highly positive correlations were observed between urinary N contents and urinary urea N in Japanese Black cows, and urinary urea N increased with increasing PUN. There were positive correlations between N intake and PUN in dry and lactating cows, but PUN and urinary N excretion in lactating cows were higher than in dry cows. There were positive correlations between PUN and urinary N excretion per BW in dry and lactating cows. Although urinary N excretion could be calculated as (N clearance rate of kidneys)PUNBW, high N clearance rate of kidneys, such as 2.08 L/d/kg BW, may be suitable to calculate urinary N excretion in lactating cows, compared with 1.33 L/d/kg BW in dry cows.

• 한국해양바이오학회지
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• 제8권2호
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• pp.45-53
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• 2016

Most of microalgae shift their metabolic pathways toward the fatty acid biosynthesis following nitrogen deprivation. Recent studies on Nannochloropsis species, oleaginous microalgae, have been performed to investigate the regulation of contents and compositions of fatty acids under stressful condition. The objective of this experiment is to identify the effect of nitrogen on cell growth and fatty acids production in Nannochloropsis oculata K-1281 and compare fatty acid composition response to nitrogen deficiency between N. oculata LB2164 and K-1281. The fatty acids content in N. oculata K-1281 was increased up to 210%, while the growth rate was decreased under nitrogen deficient condition. The contents of C16:0 and C16:1 increased dramatically in both N. oculata K-1281 and LB2164, while the contents of C20:4 and C20:5 increased in N. oculata LB2164. The fatty acids content and composition in N. oculata K-1281 returned following addition of nitrogen after nitrogen starvation. These results demonstrated that fatty acid contents and compositions under nitrogen deficiency will provide the understanding of fatty acid synthesis in microalgae.

• 소성∙가공
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• 제15권2호
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• pp.112-117
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• 2006

Sliding wear mechanism of a high nitrogen austenitic 18Cr-18Mn-2Mo-0.9N steel has been investigated. Dry sliding wear tests of the steel were carried out at various loads of IN-10N under a constant sliding speed condition of 0.15m/s against AISI 52100 bearing steel balls. Solution ($1050^{\circ}C$) and isothermal aging ($900^{\circ}C$) heat treatments were performed on the steel and the effect of the heat treatments on the wear was investigated. Wear rates of the solution-treated steel specimen remained low until 5N load, and then increased abruptly at loads above 5N. The rates of isothermally aged specimens were low and increased gradually with the applied load. Worn surfaces, their cross sections, and wear debris of the steel specimens were examined with a scanning electron microscopy. Phases of the heat-treated specimen and the wear debris were identified using XRD. The transformed phase underneath a sliding track was investigated and analyzed using a TEM. Effects of the phase transformation during the wear and $Cr_{2}N$ precipitates formed during the isothermal aging on the wear of the austenitic steel were discussed.

• 한국토양비료학회지
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• 제35권1호
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• pp.38-46
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• 2002

산국(Chrysanthemum boreale M.)은 국화과에 속하는 다년생 식물이며 우리나라에 널리 분포하는 자생식물자원으로서 오래 전부터 식용과 약용으로 널리 이용되어 왔다. 최근 건강에 대한 관심이 고조되면서 산국의 수요가 급증하고 있으나 자연채집을 위주로 하기 때문에 공급을 충당하지 못하고 있는 실정이다. 본 연구에서는 우수품질의 산국을 대량생산하기 위해 질소시비반응 시험을 실시하였다. 처리구는 질소수준에 따라 6처리구(0, 50, 100, 150, 200, $250kg\;ha^{-1}$)로 설정하였다. 이때 모든 처리구에서 기본적으로 $P_2O_5-K_2O=80-80kg\;ha^{-1}$을 시비하였다. 그 결과, 질소의 시비량이 증가할수록 수량이 증가하였다. 전체 산국을 건물중으로 하여 회귀곡선을 통해 추정한 결과 N $246kg\;ha^{-1}$였으며, 꽃의 수량은 N $226kg\;ha^{-1}$이였다. 꽃의 주요 아미노산은 proline이였고 질소의 시비량이 증가할수록 아미노산의 함량이 증가하였다. 이때 질소의 이용율은 41.5-61.8%였고 N100처리구에서 가장 높았다. Sespuiterpene계 화합물로서 우수한 혈압강하효과를 가지고 있는 물질인 Cumambrin A의 함량은 식물부위 중 꽃에 가장 많이 함유되어 있었다. 질소의 시비량이 증가할수록 Cumambrin A의 함량이 다소 감소하였으나 통계적 유의성은 인정되지 않았다. 꽃에서 Cumambrin A의 전체 함량은 산국의 수량증가에 따라 질소 시비량이 증가할수록 증가하는 경향을 보였다. 따라서 유효성분이 많이 함유된 양질의 산국재배를 위해 질소의 적정시비량은 $225{\sim}250kg\;ha^{-1}$ 수준으로 판단되었으며 포장시험을 통한 현장입증시험이 있어야 할 것으로 판단된다.

• 열처리공학회지
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• 제20권2호
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• pp.84-93
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• 2007

Microstructural changes during tempering at the temperature range of $300^{\circ}C{\sim}700^{\circ}C$ for the nitrogen-permeated STS 410 and 410L martensitic stainless steels has been investigated. After nitrogen permeation at temperature between 1050 and $1150^{\circ}C$, the surface layer appeared fine $Cr_2N$ of square and rod types in the martensite matrices. Hardness of the nitrogen-permeated surface layer represented 680Hv and 625Hv, respectively, for 410 and 410L steels. It is considered that the fine homogeneously dispersive effect of precipitates by nitrogen caused the increased hardness. Due to the counter current effect of carbon from interior to surface during nitrogen diffusion from surface to interior, the 0.1%C alloyed 410 steel showed the low nitrogen content of 0.025% compared with 0.045% of 410L steel at the distance of $100{\mu}m$ from the surface. Tempering of nitrogen-alloyed 410 and 410L showed the maximum hardness at $450^{\circ}C$. This maximum hardness was considered to be the secondary hardening effect of very fine carbide and nitride. The decrease in hardness at $700^{\circ}C$ was the softening effect of the matrix due to the precipitation of many needle-shaped $Cr_2N$ for 410 steel and the precipitation of coarse nitride of $Cr_2N$ in line with the spherical precipitates with directionality for 410L steel. For 410 steel, the corrosion resistance of nitrogen permeated surface in the solution of 1 N $H_2SO_4$ were nearly unchanged, however the superior corrosion resistance was obtained for nitrogen permeated 410L steel compared to the solution annealed condition.

• 한국유기농업학회지
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• 제13권2호
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• pp.211-221
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• 2005

This experiment was conducted to evaluate the effect of animal slurry on nitrogen uptake of hairy vetch and growth of chinese cabbage in cropping system. Hairy vetch was seeded on September 20 in 2003 . We examined the effect of cover crop(hairy vetch (Vicia villosa Roth) and slurry application(0, l00, 200kg N/ha) on yield and N uptake. Dry matter yield and nitrogen uptake of hairy vetch were measured. The chinese cabbage succeeding cover crop was harvested in 2004. The nitrogen uptake of hairy vetch was 84, 121, 148kg N/ha respectively, when the slurry application was 0, 100 and 200kg N/ha. In addition. N uptake of hairy vetch at the plot of 100kg and 200 kg N/ha slurry were 44% and 76% higher than that of the plot without slurry application respectively. Slurry application of hairy vetch could increase nitrogen uptake by application of green manure at the harvesting time. the content of organic matter and P-content of soil with hairy vetch plot was higher than that of fallow plot due to inhibition of soil erosion. The organic matter levels tend to improve with the addition of hairy vetch. Hairy vetch could improve soil quality by reducing erosion compared with bare fallow. The green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage. The hairy vetch residues decomposed rapidly releasing half of their residues within 40 days after burial. The yield of chinese cabbage was 90% in the plot of manure of hairy vetch compared with chemical fertilizer. The yield in the plot treated with green manure of hairy vetch and 50% of chemical fertilizer was reduced 5% less than that of chemical fertilizer. Therefore, it was estimated that the green manure of hairy vetch-chinese cabbage cropping system could reduce nitrogen chemical fertilizer as much as 84~148kgN/ha. the green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage.

• 한국유기농업학회지
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• 제10권1호
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• pp.49-63
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• 2002

In order to supply 85% of total organic feed in ruminants and 80% in non-ruminants for organic animal production, nitrogen fixation ability of legume should be used in domestic roughages production. 50% of Europe organic farmer use intercropping legume in as green manure. This article is dealing with amount of biologically fixed nitrogen used by legumes and methods for estimating the transfer of biologically fixed N in rotation and separating the N benefit into fixed N and non-fixed N components are reviewed. Available data indicate that transfer amount of N to non legumes was from 50∼9.6(kg/ha) in legume-cereal rotations and proportion of legume N varied with seasons, 90% in summer, 50% in autumn. The important point in cropping system for legumes have to be included for organic forage production 6 year rotation is based on pasture system of 3 year pasture + 2 year annual(com, sudangrass), again pasture. Rye, barly and Italian ryegrass+legumes(vetch, crimson and pea) can be one of option in spring, com, soybean, sudangrass and Japanese bamyard millet would be seeded after spring harvest in the field. Farmer can make good use of rice paddy field as forge production potential area after harvesting rice. Italian, burly and rye+vetch and crimsonclover may be grown in autumn or spring time at the rice field.