• Journal of Plant Biology
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• 제22권1_2호
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• pp.5-14
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• 1979

In several leguminous plants such as acasia, arrowroot and bushclover, growth rate and contents of nitrogen, phosphorus and potassium in the tissues and the variation in the culture media were determined. In water cultrue which was free of added nutrients, nitrogen was found to be largely in the form of nitrate(NO3-N). This NO3-N is believed to be the result of nitrification from NH4-N which was apparently released form the plants. From the studies of organ culture with root segments, the amount of nitrogen released and absorbed was found to be proportional to the amount added to the mediuim. Especially, in the N-plot, the amount of nitrogen absorbed by the tissue reached more than 90% of the amount supplied to the medium already in early stage. On the contrary, in the amount free plot, the amount of nitrogen released from the tissue was lower than the minimum level in the N-plot. The amount of total N and P in the cultured tissue was found to be influenced by the amount of nitrogen addedin the medium. However, the amount of K in the tissue was not related to the nitrogen level in the medium, but rather it was influenced by the amount of added potassium. These findings present little difference in the metabolic pattern among the three species plants studied, and suggest that the woody leguminous plants have some common features in tehir metabolic pattern.

• Journal of Plant Biology
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• 제20권3호
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• pp.109-118
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• 1977

Seasonal distribution of N, P and K contents and their cycling were studied in Korean oak (Quercus acutissima) and Korean alder (Alnus sibirica) stands in central part of Korean peninsula. The amounts of three minerals were high in young leaves but gradually decreased with the process of leaf development in both stands. The amounts of minerals in the branches, trunks and roots were decreased in summer, however, they increased again in autumn. Seansonal changes of these minerals were not significant in the two stands. The amounts of phosphorus and potassium in plant and soil were higher in the oak stand than the alder one, but those of nitrogen were reversed. The amounts of minerals absorbed during one year were greater in the oak stand than in the alder one, but those returned into soil through mineralization of litter were less in the former than in the latter. The nutrient requirements of the oak stand were greater than the alders, but the cycling rate, the ratio of the amount of minerals absorbed to returned, was opposite.

• Journal of Plant Biology
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• 제5권2호
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• pp.6-12
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• 1962

For the comparison with the previous paper (4) the present report deals with the absorption and metabolism of urea and other nitrogen ions in barley seedling absorbed through root. 1. The amount of nitrate in barley treated with urea reach it peak on the 8th day. NO3 on the 4th, NH4 on the 6th or 8th, respectively. 2. The ammonia content in urea group reaches its peak on the 6th day but other groups on the 4th day. The present data in the urea group show to shorten 4 days compared with that of the previous paper(4). 3. the content of total amide from the present data aare gradully increased on all of the groups during this experiment. These are agreement with the result of the previous paper (4). 4. the alcohol solution nitrogen in the urea gorup shows the similar tendency to the NaNO3 group but reaches it peak 2 days later than in the (NH4)2SO4 group. 5. The content of total nitrogen in the urea series has the lowest amount at the beginning while the richest from the 4th day after. These would be explained on that the absorption of urea is delayed and the PH in the urea solution does not change, so called "physiological neutrality". The author should like express his sincere thanks to Prof. M.J.Lee of Seoul National University for his valuable advices.e advices.

• 한국토양비료학회지
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• 제42권3호
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• pp.152-159
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• 2009

혼합유기질비료 시용 후 벼 재배시 무기태질소 함 량, 질소이용율, 수량 등을 조사하여 질소 화학비료 대체 가능성을 검토코자, 화학비료 3요소구, 혼합유기질비료 0, 100, 150% 시용구 등 5처리를 두어 2006년도에 시험을 수행한 결과는 다음과 같다. 혼합유기질비료 100% 시용구 토양 중 $NH_4-N$ 함량은 대조구에 비해 많았으며 표면수에서도 같은 경향이었다. 시험후 토양 중 Av. $P_2O_5$ 함량은 대조구에 비해 혼합유기질비료 100% 시용구에서 많았으나 Ex. K 함량은 적었다. 수도체 중 질소이용율은 혼합유기질비료 100% 시용구가 대조구에 비해 높아 질소 화학비료 대체 가능성이 있었다. 이앙 후 30일, 60일에서 경수는 혼합유기질비료 100% 시용구가 대조구 보다 많았다. 혼합유기질비료 중 질소 함량과 단백질 함량과는 정의 상관, 식미치와는 고도의 부의 상관, 완전립 비율과는 부의 상관이 있었다. 혼합유기질 비료 100% 시용구의 쌀 수량은 대조구 $4,892kg\;ha^{-1}$에 비해 4% 증가하였다. 벼 재배시 대조구의 쌀 수량과 대등한 혼합유기질비료의 시용량은 [질소 토양검정시비량 ${\div}$ 혼합유기질비료질소함량 $(g\;kg^{-1})/1,000{\times}0.93)/1,000$]으로 산출되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제11권5호
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• pp.620-633
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• 1998

Methods developed for measuring digestibility and availability of amino acids in feedstuffs used in pig nutrition are reviewed. Digestibility is a proportion of an amino acid in a feed that is absorbed from the digestive tract and should be determined from the difference between the amount of amino acid consumed and passing the distal ileum. Techniques for ileal digesta sampling including various types of cannulas: a re-entrant, T-piece, IPV, IPVC and ileaorectal anastomosis are described and comparisons amongst these methods are presented. Other methodologies like mobile bag technique, in vitro assays and mathematical prediction method are also described. Significance and methodologies for measurement of endogenous nitrogen and amino acids losses at the distal ileum and their effect on the apparent and true nitrogen and amino acid digestibilities in feeds are discussed. Factors influencing the apparent and true amino acid digestibilities such as dry matter intake, protein, fibre and antinutritive compounds content in the diet are discussed. Amino acid bioavailability -the proportion of the total amino acid digested and absorbed in a form utilized in metabolism - measured by the growth assay may differ from its ileal digestibility. Chemical methods for determination of available lysine content in heat treated feeds are evaluated.

• 한국작물학회지
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• 제37권3호
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• pp.224-229
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• 1992

본 시험은 포트실험으로서 분얼을 하는 옥수수(IK$_1$,/IRI)와 분얼을 하지않는 옥수수(장야001)의 생육기간중 주요식물학적 특성을 비교하고 또 주요양분에 대한 생육시기별 흡수량과 흡수율에 대한 변화를 알아보고자 수행되었다. 1. 분얼하는 IK$_1$ /IRI가 분얼하지 않는 장야001 보다 전반적으로 생육이 양호하여 지상부의 개체당 생체중과 건물중이 무거웠으며 식물체를 부위별로 비교하였을 때에도 이삭을 제외한 경엽중이 더 무거웠다. 2. 생육시기별 개체당 질소, 인산, 가리의 흡수량을 전체 건물중에 대한 비율로 보면 분얼형인 IK$_1$/IRI 교잡종이 분얼하지 않는 장야일호보다 낮은 경향이었으나 성숙기의 질소함량은 오히려 분얼형이 분얼하지 않는 옥수수 보다 높았다. 3. 석회 및 고토의 흡수량은 두 공시 교잡종이 비슷한 경향이었다. 4. 질소와 가리의 함양은 웅종 출현기에 최고에 달하였다가 생육후기로 갈수록 감소하는 경향이었으나 분얼하는 IK$_1$/IRI의 경우 질소함량이 성숙기에 증가하였다. 그러나 인산의 생육기별 함유량은 두 교잡종 모두 감소하는 경향이었다. 5. 경엽의 질소, 인산, 가리함량은 생육시기별로 일정하거나 다소 감소하는데 반하여 이삭에서는 생육후기로 갈수록 크게 증가하였다. 6. 흡수한 질소의 건물생산효과를 보면 전생육기간중 이삭을 제외하고 IK$_1$/IRI가 장야일호보다 높았다.

• 한국작물학회지
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• 제46권4호
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• pp.303-308
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• 2001

To investigate the partitioning of newly absorbed N derived from NO$_3$- and NH$_4$$^{+}$, 6 mM $K^{15}$ NO$_3$ or 3 mM ($^{15}$ NH$_4$)$_2$ was fed continuously in Italian ryegrass (Lolium multiflrum L.) for 7 days. Nitrogen metabolites (nitrate, amino acid, soluble- and insoluble protein) were analyzed at the end of $^{15}$ N feeding. Dry weight in shoot, stubble and root was not significantly different between NO$_3$$^{[-10]}$ and NH$_4$$^{+}$ feeding. Total nitrogen content in all three organs was significantly higher in NH$_4$$^{+}$ than NO$_3$$^{[-10]}$ feeding. Sum on N content in reduced N fractions (amino acids + proteins) in shoot, stubble and roots in NH$_4$$^{+}$ feeding increased by 13.3, 12.5 and 35.4 %, respectively, compared to NO$_3$$^{[-10]}$ feeding. The Relative Specific Activity (RSA, percentage of newly absorbed $^{15}$ N relative to total N in a sample) values of amino acids and insoluble proteins were significantly higher in NH$_4$$^{+}$ feeding. Total amount of newly absorbed $^{15}$ N in NO$_3$$^{[-10]}$ and NO$_3$$^{[-10]}$ feeding was 52.3 and 69.5 mg/plant on dry matter basis, respectively. In both NH$_4$$^{+}$ and NO$_3$$^{[-10]}$ grown plants, most of the N was allocated to the shoot, 67.5% in NH$_4$$^{+}$ feeding and 58.8% NO$_3$$^{[-10]}$ feeding, respectively. The $^{15}$ N amount incorporated in the reduced N compounds (amino acids and proteins) in NH$_4$$^{+}$ grown plants significantly increased by 74.8% compared to NO$_3$$^{[-10]}$ grown plants. The increase of the $^{15}$ N amount assimilated to amino acids in NH$_4$$^{+}$ grown plants was remarkably higher in roots as more than 7.25 times compared to NO$_3$$^{[-10]}$ feeding. These results indicated that Italian ryegrass was much efficiently utilized NH$_4$$^{+}$-N for the synthesis of reduced N compounds.reduced N compounds.

• 한국작물학회지
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• 제50권1호
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• pp.16-21
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• 2005

This study was conducted to establish the elaborate nitrogen fertilization method to enhance N use efficiency in direct-seeded rice on flooded paddy. The nitrogen uptake by rice plants was insignificant until 25 days after seeding, and increased gradually thereafter. During this early growth stage, rice plants absorbed only the $4\%$ of basal applied N, while the $45\%$ of N fertilizer remained in the paddy soil. The absorption of basal N by rice plants was almost completed at 46 days after application. Nitrogen top-dressed at 5-leaf stage was well matched to crop nutrient demand, so it could be absorbed so actively in 8days after application. As a result, we could cut down the amount of N fertilizer to $36\%$ of the basal N level without significant difference in yield. Plant recoveries of fertilizer $^{15}N$ applied with different application timings were $7.8\%$ for basal, $9.4\%$ for 5-leaf stage, $17.1\%$ for tillering stage, and $23.4\%$ for panicle initiation stage, respectively. When urea was applied with nitrogen fertilization practice based on basal incorporation (BN), plant recovery of $^{15}N$ at harvest was $31.0\%$, which was originated from $13.7\%$ for grain, and $21.3\%$ of the fertilizer $^{15}N$ remained in the soil, and the rest could be uncounted. Plant recovery of fertilizer $^{15}N$ applied with nitrogen fertilization practice based on topdressing at 5-leaf stage (TN), where N rate was reduced by $18\%$ compared with BN, was $35.1\%$ (grain $15.6\%$), and $19.9\%$ of the fertilizer $^{15}N$ remained in the soil, and the rest could be uncounted. TN showed a higher $^{15}N$ recovery than BN because it was to apply N fertilizer at a time to well meet the demand of rice plant direct-seeded on flooded paddy. We concluded that TN would be the nitrogen fertilization method to enhance N use efficiency in direct-seeded rice on flooded paddy.

• 한국수산과학회지
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• 제8권1호
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• pp.37-45
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• 1975

재동결 명태육의 냉동변성에 미치는 축합인산염처리의 영향을 밝히고져 북양산 냉동명태를 해동하여 fillet로 만든 후 sodium polyphosphate 및 sodium polyphosphate: sodium pyrophosphate(1:1, w/w) 용액에 농도별, 시간별로 침지처리하여 동결저장한 후 해동하였을 때의 육중에 흡수된 인산염량, free drip, expressible drip, drip중의 total solid, total nitrogen 및 DNA함량, 해동시의 fillet의 관능적품질 및 가열조리시 중량감소 등을 실험하여 육질변성의 정도를 비교 검토하였다. 1. 해결전 처리에 의한 육중의 인산염흡수량은 침지시간보다 처리액농도에 더욱 많은 영향을 받았으며, 본 실험 조건하의 전처리육의 인산염함량은 모두 FAO/WHO의 허용기준량이하였다. 2 Drip의 발생량은 육중의 인산염량와 역상관계를 나타 내었고 drip감소에 가장 효과적인 처리조건은 $10\%$, sodium polyphosphate액에 5분간 침지한 것으로 무처리때의 drip 량의 약 $14\%$ 였다. 3. Drip중의 total solid, total nitrogen 및 DNA 함량은 대체적으로 drip량에 비례하는 결과를 나타내었으며, 특히 DNA 감소에 미치는 축합인산염처리의 효과는 컸다. 4. 해동한 fillet의 관능적품질은 고농도처리액에 처리한 것은 광택이 있고, 육질은 강성이 있어 양호하였으나, 저농도액에 처리한 것 및 무처리의 것은 광택과 강성이 좋지 못 하였다. 5. 가열조리시의 감량은 고농도처리액에 장시간 처리한 것은 감량제어의 효과가 다소 있는 듯하였으나, 저농도액에 처리한 것을 그 효과를 인정할 수 없었다.

• 한국토양비료학회지
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• 제20권1호
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• pp.35-41
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• 1987

질산태질소(窒酸態窒素)를 선택흡수(選擇吸收)하는 담배식물에 대하여 흡수된 $NO_3-N$의 각조직별(各組織別) 이동양상(移動樣相)과 질산환원효소(窒酸還元酵素)의 활성도(活性度)(nitrate reductase activity. NRA)를 조사하고 생육과정(生育過程)에서 출엽(出葉)된 잎들의 질산환원능력(窒酸還元能力)을 비교조사(比較調査)한 결과(結果) 1. 도관조직(導管組織)인 엽맥(葉脈)까지는 함유(含有)된 질소(窒素)의 대부분(大部分)이 $NO_3-N$으로써 무기태질소(無機態窒素)로 엽맥(葉脈)을 통과(通過)하며 엽육(葉肉)에서는 $NO_3-N$이 환원(還元)되어 무기태질소(無機態窒素)가 거의 검출(檢出)되지 않았다. 2. NRA는 성숙(成熟)된 잎에서 가장 왕성하였으며 분열생장중(分裂生長中)인 잎이나 도관조직(導管組織)에서는 환원기능이 매우 낮은 수준에 머물렀다. 3. 하위(下位)의 성숙엽(成熟葉)은 두껍고 수분(水分)을 많이 함유(含有)하였으며 가장 왕성한 질산환원능력(窒酸還元能力)을 보였다. 4. 생장조직(生長組織)으로 유기질소물질(有機窒素物質)을 공급(供給)하기 위하여 유식물(幼植物)때는 소수(小數)의 좁은 잎에서 높은 수준(水準)의 NRA를 유지(維持)했으나 생육(生育)이 진전되어 많은 잎이 착엽(着葉)되면서 상위(上位)쪽의 성숙엽(成熟葉)은 NRA가 낮은 수준에 머물렀다.