• Asian Journal of Turfgrass Science
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• v.10 no.2
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• pp.125-142
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• 1996

Crassulacean acid metaholism (CAM) was investigated in leaves and stems of the succulent $C_4$dicot Portulaca oleracea L. Under 14-hour days, stem tissues showed much greater fluctuation of acidity than leaf tissues. But leaf and stem tissues showed almost same CAM-like pattern of acid fluctuation under 8-hour days. Stem tissues of R oleracea grown under the naturai environment showed high CAM activity, but no CAM activity was seen in leaves of those plants. In the naturally growing plants, the rapid acidification was seen in intact stems at dawn, but defoliated stems showed only a gradual increase. RuBP carlboxylase activity was very high at 2:00 P.M. in both leaves and stems. However, its activity at 1:00 A.M. and 5:30 AM. was hardly detected. particularly, activity of PEP carboxylase in leaves was very high in the early morning, though that in stem tissues was little. These results indicate that $CO_2$ passed through open stomata at dawn may be assimilated by PEP carboxylase in leaves, and then $C_4$ products move to stems. The levels of nitrate concentration and of nitrate reductase were higher in stems than in leaves. The levels were also higher in the light than in the dark. It would be suggested that considerable amount of nitrate absorbed from roots ho assimilated in stems, and nitrate transferred to leaves via stem tissues be reduced there. Key words: Portalaca oleracea, Cactus, Photosynthesis, Nitrogen assimilation, Crassulacean acid metabolism (CAM).

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.5
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• pp.358-364
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• 2001

To obtain information for the proper fertilization management of cut-flower roses, the amount of macro and micro elements absorbed by cut-flower roses from soil for a year was investigated. Three cut-flower rose cultivars which are called 'Grandgara', 'Nobless', and 'Centina' were transplanted to a sandy loam soil, N-P-K standard fertilization was applied to the soil, and drip irrigation was done at the level of 10 kPa soil moisture tension. There was not significantly different in the harvest amount of cut-flower rose between 'Grandgara' and 'Nobless', but the harvest yield of 'Centina' was about 63% level when compared to that of 'Grandgara'. Considering seasonal changes in the content of nutrients in plant, parts, the uptake of untrients was higher in winter season than that in spring and summer seasons. Except for 'Centina', the nutrient amount removed from plant parts of 'Grandgara' and 'Nobless' increased with the sequence of floral part < stem < leaf, indicating that it is more dependent on biomass yield than on the content of nutrients in each plant part. The ratio of N/K amount absorbed by 'Nobless' and 'Centina' was 1.13 and 1.28. respectively, lower than 1.68 of 'Grandgara', showing that the requirement for K is greater in 'Nobless' and 'Centina' than in 'Grandgara'. The use efficiency of nutrients by cut-flower roses ranged from 39 to 64% in nitrogen, 5 to 9% in phosphorus, and 37 to 67% in potassium. It suggests that the requirement for P in cut-flower roses is very low.

• Journal of Radiation Industry
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• v.5 no.1
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• pp.69-73
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• 2011

Polyamide 66 (PA66) nanofibers with Triallyl cyanurate (TAC) were obtained by electrospinning of formic acid and chloroform solution. Electron beam irradiation of PA66 nanofiber with and without TAC was carried out over a range of absorbed doses (20~100 kGy) in nitrogen. The characterization of the irradiated PA66 nanofibers and PA66 nanofibers with TAC was done by scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA) and universal testing machine (UTM). The results of the SEM image analysis confirmed that the morphology of PA66 nanofibers was not altered by electron beam. The amount of TAC in PA66 nanofiber with TAC was identified by $^1H-NMR$ analysis. The degradation temperature of PA66 nanofibers with TAC at an absorbed dose of 20~100 kGy was higher than the irradiated PA66 nanofiber without TAC. On the other hand, the decreasing rate of modulus of irradiated PA66 nanofibers with TAC was less than PA66 nanofibers.

• The Korean Journal of Ecology
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• v.19 no.4
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• pp.341-351
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• 1996

In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

• Korean Journal of Weed Science
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• v.10 no.2
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• pp.93-98
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• 1990

Interspecific competition between E. colona and rice was determined over four growth stages in replacement series. No competition between the two species as measured by plant height, leaf area and dry weight occurred by 30 days after seeding (DAS) at all the density combinations studied. At 45 DAS reductions in leaf area and dry weight of E. colons due to the competition occurred at the density combinations where number of competing E. colons plant was less than that of rice. However, there was a great increase in leaf area and dry weight of E. colons at the density combination of one E. colons competing with four rice plants at 60 DAS. As the number of E. colons plants increased, the leaf area and dry weight of E. colona decreased resulting from intraspecific competition between E. colons plants. Although rice absorbed more nitrogen than E. colons up to 30 DAS, the reverse was observed from 45 DAS. A relatively small amount of phosphorous was absorbed by both rice and E. colons, but the amount of phosphorous taken up by E. colons was greater than that taken up by rice. E. colons absorbed extremely high amount of potassium when compared to rice.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1255-1261
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• 2005

The objective of this study was to evaluate the net flux response of nitrogen compounds (alpha-amino N, ammonia N, urea N, essential amino acids) across the portal-drained viscera (PDV), liver and total splanchnic tissues of mature wethers to increasing level of dietary fishmeal (FM) supplementation. Four wethers (average body weight, 64 kg) with chronic indwelling catheters into the portal, hepatic and mesenteric veins and the abdominal aorta were used in a 4${\times}$4 Latin square design. A basal diet consisting of 0.7 hay and 0.3 concentrate was fed twice daily with a fixed amount at 1.4 times maintenance energy (1.3 kg/day on a dry matter basis). The supplementation proportion of FM as treatment was 0, 0.03, 0.06 and 0.09 to the amount of the basal diet to contain 119, 137, 154 and 170 g crude protein per kg dietary dry matter, respectively. Blood flows through PDV and liver did not differ (p>0.05) among the treatments. Both net PDV release and hepatic uptake of alpha amino acid N increased linearly (p<0.05) in response to increased dietary FM, which resulted in similar total splanchnic release of alpha-amino N among the treatments. Similarly, increased dietary FM increased net PDV absorption and hepatic removal of ammonia N linearly (p<0.05). Hepatic synthesis and total splanchnic release of urea N increased linearly (p<0.01) with increased dietary FM, but PDV uptake of urea N did not respond to increased dietary FM. Linear regression equations between the increases in FM N intake and PDV net flux indicated that 0.34 and 0.30 of FM N was absorbed in the form of alpha-amino N and ammonia N, respectively. The results demonstrated that FM supplementation provides more alpha-amino N than ammonia N to the liver, but the alpha-amino acid N absorption is less than the expected metabolizable protein N from FM supplementation.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.4
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• pp.270-276
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• 1982

Water culture experiment with mulberry (Morus alba L.)was carried out to investigate the ionic composition in the exudate and the ionic content in the organs (leaves, petioles, stem cortex, and roots) of mulberry tree with three different nitrogen sources ($NO_3-N$, $NH_4-N$, and $NH_4NO_3$). 1. Amount of exudate was much lower for $NH_4-N$ than for $NO_3-N$. 2. Total nitrogen content in the exudate was the highest in the NH4-N, the order of 2.2 times than in the $NO_3-N$. However, total nitrogen amount absorbed by tree per hour was proportional with the exudate amount. As the result, total nitrogen amount was higher 1.6 times in $NO_3-N$ ($289.6\;me\;plant^{-1}\;hr^{-1}$ than in $NH_4-N$. 3. Ammonium nitrogen depressed $Ca^{2+}$ uptake critically and even all of the anions, whereas $Mg^{2+}$, $K^+$ and $Na^+$ affected little. 4. Reduction of $NO_3$ may occured both in root and in leaves. 5. Content of cations and anions was highest in petioles, except $Ca^{2+}$ which was highest in leaves. As the result, petioles may be the storage organ of nutrients. 6. By increasing $NH_4-N$, ionic balance (C-A) decreased proportionally. 7. Nutrients amount in the exudate were approximatelly proportional with the amount in the roots. This suggested that roots may be the part diagnosed for nutrients. Being the sum of anions (${\Sigma}A$) higher than that of cations (${\Sigma}C$) in the roots, the ionic balance showed negative value.

• The Korean Journal of Ecology
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• v.15 no.1
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• pp.35-46
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• 1992

To elucidate nutrient cyclings such as nitrogen, phosphorus and potassium in mongolian oak(quercus mongolica) forest, nutrient elements of precipitation, throughfall, outflow, soil, various plant organ and litter were determined at mt.nambyeongsan, pyeongchang-gun, gangwon province in central part of korean peninsula. Annual precipitation input, throughfall and outflow of nutrientswere 10.3, 8.6 and 4.2 kg/ha for the N, 0.11, 0.24 and 0.02 kg/ha for the Pand 1.3, 10.9 and 1.2 kg/ha for the K, respectively. Inseasonal changes of nutrient concentrations, N, P and Kconcentrations which were rich in young leaves decreased steadily until autumn and decreased abruptly during autumnal yellowing. The standing N, P and K concent were 565, 37 and 257 kg/ha for standing phytomass of overstory, 33, 3 and 18 kg/ha for understory, 132, 3.6 and 14 kg/ha for litter on ground including deadwood and 20, 752, 14 and 420 kg/ha for the soil, respectively. The amounts of annual uptake, reture and retain were 174.2, 57.2, 117.2 kg/ha for the N, 9.9, 3.5, 6.4 kg/ha for the P and 73.2, 30.3, 42.9 kg/ha for the K, respectively. Reabsorption efficiency, ratio of the nutrient amount reabsorbed into woody organs to that in the mature leaves before shedding, was 71%(or 99.8 kg/ha in the amount), 69%(or 5.1 kg/ha) and 57%(or 33.1% kg/ha) and recycling coeffciently made with which the large amount of nutrients is absorbed through roots during growing season(UPTAKE) and reasorbed from the leaves before shedding(RETAIN) but the small amount of nutrients is returned through litterfall(RETURN).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.105-118
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• 2015

This study was conducted to obtain proper amount of solid swine manure and poultry manure in the beginning phase of Cornus kousa growth by investigating the initial germination, seedling growth increment, dry weight, chlorophyll content change, body nutrient uptake and chemical changes of soil according to the concentration of solid swine manure and poultry manure fertilization. When treated with solid swine manure and poultry manure, seed germination rate was the highest in the control. However germination rate showed a tendency to decrease when treated with high concentration of swine manure and poultry manure. The survey results of the growth increment were all higher than that of the control. At the 1.0% treatment of both swine and poultry manure, the seedling height growth was highest. Poultry manure treatment made higher result than swine manure treatment at each treatment. Dry weight was the highest at the 1.0% treatment by both swine and poultry manure. Dry amount declined sharply at the 2.0% treatment. Poultry manure was higher in weight than swine manure at every treatment. Chlorophyll content was the highest at the 1.0% treatment by both swine and poultry manure, but declined sharply at the 2.0% treatment. The survey content was higer than that of the control. The amount of nutrients absorbed in the seedling body was generally high at the 1.0% treatment of swine manure and poultry manure. For the planting soil of Cornus kousa the higher concentration of swine manure and poultry manure was, the lower pH became. However, nitrogen, got higher. available phosphoric acid, exchangeable K, Na, and Mg got higher.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.69-80
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• 1975

Relationships between yield and various nitrogen efficiencies, between efficiencies and between efficiency and nitrogen uptake amount of rice plant were proposed and tested using data from N.P.K simple trials about 30 to 50 locations, for three years. Established relationships are well in accordance with experimental results by showing highly significant correlations between them. The overall indications are that high yielding capacity of fields with fertilizer application, depends primarily on high fertilizer nitrogen uptake by increasing fertilizer use efficiency (Eu), secondly the efficiency (Ef) of absorbed fertilizer nitrogen (Nf) and fertilization efficiency (Fe) and also depends much on nitrogen efficiency for grain yield (E) to great extend and that the efficiency (Es) of soil nitrogen (Ns) contributes to E more than Ef does. All nitrogen efficiencies are negatively correlated with the uptake amount of corresponding nitrogen and counterpart efficiency. Es and Ef could be determined firstly by difference method and secondly E versus Cs (Cs=Ns/Ns+Nf) plotting and thirdly E-Cs plotting with labelled fertilizermethod using the equation E=Es Cs+B where B=Ef Cf but a constant under the given condition and at last Y-Ns plotting with labelled fertilizer using Eq Y=$Es{\cdot}Ns+B$ where B=$Ef{\cdot}Nf$. Es which seems not much variable from field to field is mostly greater (about 80% of tested fields) than Ef which is much variable and depends much on fertilizer form. The relationships tested and well agreed are as follows: 1. Y=$Es{\cdot}Ns+Ef{\cdot}Nf$ (Y is yield) 2. E=$Es{\cdot}Cs+Ef{\cdot}Cf$ where Cf=Nf/Nf+Ns 3. E=b-aN where E=E, Es or Ef and N=N, Ns or Nf respectively, (E=Y/N, N=Nf+Ns), b is theoretical maximum under the given system and a is tangent at N=O of the curve, Y=EN. 4. Fe=Ef Eu and Se=$Es{\cdot}Eu$ where Se is efficiency of soil available nitrogen. 5. E=$(Se{\cdot}Cs+Fe{\cdot}Cf)/Eu$ 6. Y=$Es{\cdot}Eu{\cdot}Sf+Ef{\cdot}Eu{\cdot}Fn$or Y=$Es{\cdot}Eu{\cdot}Ea{\cdot}Sn+Ef{\cdot}Eu{\cdot}Fn $where Sf=$Ea{\cdot}Sn$, Ea is soil available nitrogen equivalent to fertilizer(Sf) divided by total soil nitrogen (Sn).