• Korean Journal of Soil Science and Fertilizer
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• v.7 no.2
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• pp.113-118
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• 1974

A study was carried out to investigate the effect of application time of fertilizer nitrogen on its rate of uptake and its distribution in rice plant. The rate of applied fertilizer was 100kg/ha, as a single application at transplanting time and four equal split applications of 25kg/ha was applied at transplanting time, 3 weeks after transplanting, 1 week before the primodial initiation stage of growth and at the flag leaf stage of growth, respectively. The ammonium sulfate was labelled with N-15, as 1% atom excess for single application and 4.4% atom excess for split applications. The results are sumarized as follows: 1. The effect of split application of nitrogen on yield was observed. The yield of brown rice of the single application at transplanting time was 3.1 ton/ha and the split application was 3.4 ton/ha. However, without nitrogen the yield was reduced to 1.9 ton/ha. 2. The number of grains per panicle and 1000 grains weight were increased as split application of nitrogen, but for the number of panicles per hill and maturing rate, the single application of nitrogen revealed favorable results. 3. The rate of uptake of applied fertilizer nitrogen showed a tendency that the efficiency of fertilizer nitrogen increased by top dressing. The rate of uptake of applied nitrogen as basal application, first top dressing, second top dressing and third top dressing was 28%, 33% 51% and 63%, respectively. 4. After shooting stage of the growth, nitrogen in straws transfered to grains. The nitrogen applied at flag leaf stage was absorbed by root and easily accumulated in grains rather than straw.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.773-777
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• 2008

Phosphate solubilizing bacteria (PSB) were isolated from the rhizosphere of Chinese cabbage and screened on the basis of their solubilization of inorganic tricalcium phosphate in liquid cultures. Ten strains that had higher solubilization potential were selected, and they also produced indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and siderophores. The strains were identified to be members of Pseudomonas, by 16S rDNA sequence analysis. Seed bacterization with PSB strains increased the root elongation and biomass of Chinese cabbage in seedling culture, although they had no effect on phosphorus uptake of plants. The plant growth promotion by PSB in this study could be due to the production of phytohormones or mechanisms other than phosphate solubilization, since they had no effect on P nutrition.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.18-21
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• 2002

Phytoremediation which uses plants to enhance the bioremediation through stimulation of microbial activity and root uptake, has been a topic of increasing interest. Mathematical model were developed that can be applied to various bioremediation methods in the unsaturated zone, especially phytoremediation, for simulating the fate and transport of contaminants under field conditions. A 2-year field study was conducted using 72 (1.5m long and 0.1 m diameter) column lysimeters with four treatments: Johnsongrass; wild rye grass; a rotation of Johnsongrass and wild rye grass; and unplanted fallow conditions. The developed model represented the fate and transport of contaminant both in vegetated and unplanted soils satisfactorily for field applications. Parameters related to the contaminant concentration in the water phase were the main parameters determining the contaminant fate in the vadose zone and indicated that the bioavailability can be the most important factor in the success of phytoremediation as well as bioremediation applications.

• KSBB Journal
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• v.8 no.2
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• pp.104-109
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• 1993

A vector for plant transformation which had two reporter genes(Gus and Hpt genes) in a single plasmid was constructed. After rice embryos imbibed DNA solution, DNA uptake and gene expression in rice were monitored. Main expression sites of the Gus gene were meristem of root and coleoptiles. There was no difference in Hpt gene expression between a single Hpt vector and the constructed vector in viability of rice in the hygromycin medium after DNA imbibition, The genomic DNA and total RNA extracted from rice transformant survived in the hygromycin medium were subjected to PCR and RT PCR analysis, respectively. As a result, we found the existence of the Hpt gene and its expression in rice.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.115-124
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• 1984

Chlorsulfuron (chemical name : 2-Chloro-N-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)-aminocarbonyl-benzenesulfonamide) is a herbicidally active ingredient which shows effect against susceptible weeds already at such low rates like 5-20g active ingredient per hectare. In the here reported trials metabolism in several sensitive cultivated plants and weeds have been analysed using ^{14}C-labelled active ingredient. The uptake of chlorsulfuron by leaves or the root system is good in all plants species, and translocation takes place either symplasmatically or apoplasmatically. Metabolism takes place in all investigated plant species by development of hydrophile suhstances in roots and shoots. Decomposition of chlorsulfuron in roots and shoots of tolerant species (Triticum aestivum and Hordeum vulgare) to polare substances takes place quantitatively faster and quicker than in susceptible species (Beta vulgaris and Matricaria chamomilla).

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.264-268
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• 1997

Microbial metabolites from rhizosphere soil samples mainly inhabitated by Streptomyces are selectively uptaken into plants. The culture broth of a Streptomyces strain K9301 showed a major metabolite which disappeared in the medium 24hrs after planting of seedlings. This metabolite was selectively uptaken in the rice plants as well as the wheat plants. We identified the targeted metabolite showing a strong UV-absorbing spot at Rf 0.6 on TLC to be 2-aminobenzamide.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.550-556
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• 2000

Three floating islands were constructed on the surface of the reservoir, each consisting of 10 16-㎡ (4${\times}$4 m) segments, made of wood frames and floats. Three species of aquatic macrophytes were planted in each island on June, 1998. Phragmites australis was considered as the suitable aquatic macrophyte for the floating islands since it maintained the most efficient root and shoot balance among the macrophytes. The net primary productivity of P. Australis was 3,604 g/㎡ based on dry weight in 1999, with uptake rates of nitrogen and phosphorus estimated at 77.4 g/㎡/yr and 5.7 g/㎡/yr, respectively. The result of water quality simulation for the floating islands showed that, through adsorption of nutrients and light screening, they could reduce the amount of phytoplankton, thereby decreasing COD concentration.

• The Korean Journal of Ecology
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• v.15 no.3
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• pp.297-309
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• 1992

The growth of digitaria adscendens and eleusine indica, annual weeds common in japan, was experimentally analyzed under varying untrient conditions. compared with e. indica, d. adscendensshowed a higher the two under high nitrogen availability. Higher net assimilation rate(nar) in d. adscendens than e. india was responsible for high RGR in D. adscendens under the low nitrogen availability. The different of NAR in the two species was induced not by leaf nitrogen content but by nitrogen use efficiency. Under unfertilized conditions nitrogen uptake rate(nur) was greater in d. adscendens than e. indica. Specific absorption rate in two species was similar, but root mass was greater in d. adscendens than e. indica.d. adscendens allocated more dry matter to roots than e. india earlier stage of seedlings. The contributed to higher rot mass and in turn resulted in higher nur in d. adscendens than that in e. india. It is concluuded that the larger allocation of dry matter to roots at early seedling stage in d. adscendens plays an important role in obtaining nitrogen for the continuation of growth under low nitrogen availability.

• Nuclear Engineering and Technology
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• v.35 no.2
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• pp.171-177
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• 2003

A dynamic compartment model was required for the prediction of radiological consequences of the tritiated vapor released from the nuclear facility after an accident. A computer code, ECOREA-T, was developed by incorporating the unit models for the evaluation of tritium behavior in the environment. Dry deposition of tritiated vapor from the atmosphere to the soil was calculated using a deposition velocity. Transport of tritium from the atmosphere to the plant was calculated using a specific activity model, and the result was compared with the Belot's analytic solution. Root uptake of tritiated water from the soil and formation of OBT from T were considered in the model. The ECOREA-T code was verified by comparing the results from the other computer codes using a scenario developed through BIOMOVS II study. The results showed good agreements.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.340-344
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• 2005

Salinity problems are caused from the accumulation of soluble salts in the root zone. These excess salts reduce plant growth and vigor by altering water uptake and causing ion-specific toxicities or imbalances. In this investigation, green pepper cultivation technique using mixture bed of soil and rice hull and surface drop fertigation system was examined to prolong the productivity of salt-affected plastic film house soils. Green pepper growth was better in the mixture bed of soil and rice hull comparing to the conventional soil cultivation. Especially root growth was much better and the root had more thin root system in the mixture bed of soil and rice hull. The better growth of root may be due to the better physical conditions and lower EC in the mixture bed of soil and rice hull where nutrient supply was well-managed with fertigation system. In the cultivation with mixture bed of soil and rice hull, fruit yield of green pepper was significantly higher; increased by 43% in comparison to the conventional soil cultivation. Pepper cultivation technique using mixture bed of soil and rice hull and surface drop fertigation system is expected to be a useful method for maintaining and prolonging the productivity of salt-affected plastic film house soils.