• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.230-235
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• 1999

To study the effects of an urease inhibitor, N-(n-butyl)-thiophosphoric triamide (NBPT), and a nitrification inhibitor, dicyandiamide (DCD), on nitrogen losses and nitrogen use efficiency, urea fertilizer with or without inhibitors and slowrelease fertilizer (synthetic thermoplastic resins coated urea) were applied to direct-seeded flooded rice fields in 1998. In the urea and the urea+DCD treatments, NH$_4$$^{+}$ -N concentrations reached 50 mg N L$^{-1}$ after application. Urea+NBPT and urea+ NBPT+DCD treatments maintained NH$_4$$^{+}$ -N concentrations below 10 mg N L$^{-1}$ in the floodwater, while the slow-release fertilizer application maintained the lowest concentration of NH$_4$$^{+}$ -N in floodwater. The ammonia losses of urea+NBPT and urea+NBPT+DCD treatments were lower than those of urea and urea+DCD treatments during the 30 days after fertilizer application. It was found that N loss due to ammonia volatilization was minimized in the treatments of NBPT with urea and the slow-release fertilizer. The volatile loss of urea+DCD treatment was not significantly different from that of urea surface application. It was found that NBPT delayed urea hydrolysis and then decreased losses due to ammonia volatilization. DCD, a nitrification inhibitor, had no significant effect on ammonia loss under flooded conditions. The slow-release fertilizer application reduced ammonia volatilization loss most effectively. As N0$_3$$^{[-10]}$ -N concentrations in the soil water indicated that leaching losses of N were negligible, DCD was not effective in inhibiting nitrification in the flooded soil. The amount of N in plants was especially low in the slow-release fertilizer treatment during the early growth stage for 15 days after fertilization. The amount of N in the rice plants, however, was higher in the slow-release fertilizer treatment than in other treatments at harvest. Grain yields in the treatments of slow-release fertilizer, urea+NBPT+ DCD and urea+NBPT were significantly higher than those in the treatments of urea and urea+DCD. NBPT treatment with urea and the slow-release fertilizer application were effective in both reducing nitrogen losses and increasing grain yield by improving N use efficiency in direct-seeded flooded rice field.field.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.72-76
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• 1983

Absorption pattern and sensitivity of radishes to boron were compared with different boron treatment: soil application, foliar spray and no boron application. Six radish cultivars were planted on April 7 and harvested on June 23. Borax 1.5 Kg per 10 a was applied to soil before seeding and the 150 litters of 0.5 ppm solution with bolic acid was sprayed on leaves 3 times during the growing period. Boron content in plant was markedly increased by the soil application but no significant difference in boron contents in plants was observed between foliar spray and no application, presumably because of the insufficient dose of foliar spray. The darkening rot in root, a boron deficiency, was negligible in radishes grown in soil application plots whereas a relatively higher percentage of boron deficient plant was found from foliar spray or no application plots. The appearance of root darkening rot occurred at the rapid root enlargement stage, apparently from 55 days to 65 days after seeding. The boron contents in plants of soil application plots slightly increased at this stage while those of no boron application and foliar spray decreased. This obviously verified that boron deficiency should cause root rots showing highly significant relationship.

• Korean Journal of Medicinal Crop Science
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• v.24 no.2
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• pp.101-109
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• 2016

Background: The purpose of this study was to evaluate methods to reduce seeding expenses, thereby increasing farm income. This study investigated the effects of rain shelter controlled cultivation and adapted seeding times on the stable seed production of Scutellaria baicalensis Georgi. Methods and Results: Seed germination was conducted under 10 condition compose to control, water washing, cold storage at $4^{\circ}C$ for 15 days, seed sterilization with a benomyl pesticides, hormone treated seed by submerging in 100 ppm $GA_3$ with the cold storage at $20^{\circ}C$ and $25^{\circ}C$, darkness in a covered petridish and illuminated with a 1,500 Lux lamp. There were three cultivation type, open cultivation with non-woven fabric mulching, cultivation with a vinyl covering and rain sheltered in a plastic greenhouse. Sowing dates were April 27, May 18, June 7 and June 28, 2013. Plants were spaced 10 cm apart in rows 30 cm apart. Mixed oil cake fertilizer, $N-P_2O_5-K_2O$ (12-10-10) was applied at $600kg{\cdot}10a^{-1}$. Conclusions: Optimum germination occured in darkness at $25^{\circ}C$ and cold storage after submerging in $GA_3$. The highest seed yields ($4.5kg{\cdot}10a^{-1}$) occurred in the plastic greenhouse for the April 25 sowing. The highest root yield (17%) was found on April 1, under greenhouse conditions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.4
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• pp.98-109
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• 2004

This study was conducted to develop revegetation methods for the restoration of the steep slopes by recycling of bark compost and mushroom media. In general, bark compost and mushroom media can be used as soil media for the restoration works, because they can increase infiltration of rainfall and give enough porous to breathe and elongate for the root growth as well as environmental value. This experiment was carried out to know the effect of soil media composed by different ratio of mushroom media for the restoration of steep rock-exposed slopes, and to certificate how soil media(PEC) will be effective to germinate and grow for native plants. The main results of the study are summarized as follows; 1. In percent coverage, the soil media PEC1 is more valuable than PEC2. The seed mixtures recommended by Government of Transportation and Construction can be used at PEC1 and PEC2, but it will be more useful if the total amount of seed are reduced and seed mixtures are altered in a direction of native plants. 2. The soil media is under 20 mm tested by Yamanaka Hardiness Tester which is available for the seed germination and growth. 3. The surface cracks are not occurred in PEC1 and PEC2, but more than 30 cracks per 1 square meter are occurred at soil media which is constructed by normal soil-seed-fertilizer hydro-seeding methods. 4. The soil moisture contents are over 20 percent level during 15 day. Such moisture content in soil media will be effective for the plant growth. By using Terra-Control, PEC can maintain enough soil moisture. 5. The eroded soils from $60^{\circ}$ slopes by artificial rainfall with the intensity of 20 mm/hr in one day after seeding are estimated under 1%. By the results of erosion test, it comes to the conclusion that soil media of PEC can be adapted at steep rock exposed slopes.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.44-51
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• 2012

This study was conducted to predict the rice yield loss and to determine the economic threshold levels for direct-seeding flooded rice cultivation from competition to the most serious perennial weeds, Cyperus serotinus Rottb. and Echinochloa crus-galli L. The rice yield loss model of C. serotinus and E. crus-galli were predicted as Y = 560 kg/(1+0.001883x), $r^2$=0.933, and Y = 507 kg/(1+0.001734x), $r^2$=0.867, respectively. In comparison of the competitiveness represented by parameter ${\beta}$, it was 0.001883 in C. serotinus and 0.001734 in E. crus-galli, respectively. Economic thresholds calculated using Cousens' equation were negatively related with the competitiveness of weed. The economic thresholds of C. serotinus and E. crus-galli were 15.5 and 2.3 plants per $m^2$, respectively.

• Korean Journal of Weed Science
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• v.31 no.4
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• pp.340-347
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• 2011

This study was conducted to predict the rice yield loss and to determine the economic threshold levels for direct-seeding flooded rice cultivation from competition to the most serious weeds, Sagittaria trifolia L. and Bidens frondosa L. The rice yield loss models of S. trifolia and B. frondosa were predicted as Y = 497.0/(1+0.003760x), $R^2$=0.869 and Y = 486.0/(1+0.007612x), $R^2$ = 0.887, respectively. In comparison of the competitiveness represented by parameter ${\beta}$, it was 0.003760 in S. trifolia and 0.007612 in B. frondosa, respectively. Economic thresholds calculated using Cousens' equation was negatively related with the competitiveness of weed. The economic thresholds of S. trifolia and B. frondosa were 7.6 and 3.9 plants per $m^2$, respectively.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.390-401
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• 2023

The purpose of this study was to identify the propagation characteristics of Diabelia spathulata (Siebold & Zucc.) Landrein through seeding and cutting methods. The seed germination rate was meager (0.22~3.56%). In hardwood cutting, the highest rooting rate was 36.1% in sand + perlite (2:1) and 37.8% in 1000 PPM of IBA pre-treatment. Softwood cutting showed the highest rooting rate when the cutting diameter was 3 to 5 mm and the cutting length was 7 to 8 cm. In particular, the highest rooting rate of 80% was observed in the sand among the 8 cultivation media treatments. In the case of root cuttings, the rooting rate was 83.3~96.7% in all cultivation media. The highest rooting rate was observed when the diameter of the cutting was 7 to 8 mm, and the length of the cutting was about 10 to 11 cm. Among cutting methods, root cutting showed the highest rooting rate. Division showed a 100% rooting rate regardless of size or growth status. For Diabelia spathulata (Siebold & Zucc.) Landrein, propagation by cuttings was more efficient than seeding. However, Further research on the morphophysiological dormancy and dormancy break of seeds is needed for seed propagation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.4
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• pp.70-82
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• 2007

Aiming at nature's early restoring needs to select plant species harmonizing with surrounding environment that fits to restoring goal of ultimately aiming at woody plants dominant vegetation that protect and stabilize surface parts of bared slopes. And it is important to make it assimilated with surrounding natural vegetation by differentiating planning of seed mixtures. Natural Ecological Restoring Construction Methods (JSB Method) was developed to increase the effect of landscape change according to seasons not to simple hydro-seeding by reducing rate of foreign grasses while raising rate of wild flower using. It was considered that using wild flowers that bloom on each season solved the problems of slope landscapes that looks artificial and uninteresting. After researching environmental condition of the slopes, JSB Method has shown that, as of wet-type method, soil is relatively soft and the difference of thickness of plant base soil media affects on the difference of soil hardness. In case of soil hardness of 8.8~17mm, there's dangerousness of slope's collapsing, but it has shown that growth of plant was favorable. For the acidity of soil, most of them are in the type of neutralized soil of more than pH 6. And after analyzing the degree of woody plants dominance, it had shown that lower part was occupied with wild flowers and other herbaceous species like China pin, golden phesant mum, pitcher plant, and middle and upper part was occupied with woody plants like silk-tree, sumac forming multi-layer structure. It can be concluded that the restoration objects of the woody plant vegetation on the roadside slopes can be accomplished successfully by Natural Ecological Restoring Construction Method (JSB method).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.3
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• pp.86-95
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• 2004

This study was conducted to develop recycle revegetation methods for the restoration of the steep slopes by using fresh wood chip from construction sites. In general, the fresh wood chips can be used as soil media for the restoration works, because they can increase infiltration of rainfall and give enough porous to breathe and elongate for the root growth as well as economic value. The experiment was carried out to compare the effect of fresh wood chips from different mixing with soil, organic material and macromolecular compound which used for slope restoration works conducted by Hyunwoo green(Ltd.). The main results by monitoring for two years are summarized as follows; 1. The soil media made with low percentage of fresh wood chip covered quickly by herb plants. Especially, the soil mixture Type C (wood chip 20%) showed 80 percent ground coverage within two months after seeding. 2. The soil mixture type E (wood chip 40%) and type F (wood chip 50%) which contains more fresh wood chips than soil type C was under 30 percent ground coverage because wood plants are germinated well. If the restoration works aims at making forest, then the soil type E and F would be recommended than using soil type C. 3. Among the woody plants, Ailanthus alfissima, Pinus rigida, Pinus densiflora, and Albizzia julibrissin showed high percentage of germination rates and vigorous growth. In case of shrubs, Lespedeza cyrtobotria and Indigofera pseudo-tintoria scored high percentage of germination rates. 4. In native plants, Chrysanthemum indicum, Artemisia princeps, Lutos corniculatus and Imperata cylindrica showed high percentage of appearance. In case of introduced herbs, Coreopsis lanceolata, Coreopsis tinctoria and Oenothera oborata grew so vigorously. 5. The soil types which including fresh wood chips over 30-40 percentage showed the most diverse plant composition and the most effective germination rates and growth pattern with woody plants. 6. This works to develop recycle revegetation methods using fresh wood chips need more efforts for monitoring the exact effect of fresh wood chips as the soil media.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.1
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• pp.17-25
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• 2015

The following experiments were used to evaluate the effect of seeding method and pre-emergence herbicides on weed control and the production of the $sorghum{\times}sudangrass$ [sorghum bicolor (L.) Moench] hybrid under field and in vitro conditions. Under the in vitro condition, we evaluated how different kinds of herbicides affect the rate of seed germination and the growth of early seedlings in the $sorghum{\times}sudangrass$ hybrid treated with herbicides. Simazine, alachlor, and methabenzthiazuron were used, and their concentration levels were 0%, 40%, 70%, and 100%. The germination ratio of the seeds was reduced by the application of simazine, methabenzthiazuron, and alachlor compared with the control (distilled water). The alachlor application severely decreased the sorghum germination ratio. However, seed germination was not greatly influenced by the concentration level of the herbicides. Root and shoot length were increased in the following order: control > simazine > methabenzthiazuron > alachlor. Overall, alachlor significantly reduced root length more than shoot length. The differential tolerance of the $sorghum{\times}sudangrass$ hybrid to pre-emergence herbicides by seeding method was then tested under the field condition. The plants were severely injured by the alachlor application, leading to a great reduction in the number of stems. However, for the simazine and methabenzthiazuron applications the number of stems lost was slightly lower than it was for the alachlor and simazine + alachlor applications. In the seeding method, drilling was more effective in reducing herbicide injury than broadcasting. All of the herbicides effectively controlled weeds. The simazine and methabenzthiazuron applications showed a significantly higher dry matter (DM) yield. However, the alachlor and simazine + alachlor applications severely reduced the DM yield. This result suggests that the alachlor application has a significant effect on plant production. Similarly, the total digestible nutrient (TDN) yield was greatly reduced by the alachlor and simazine + alachlor applications. From the results presented above, we concluded that the yield of DM was the highest for broadcasting with no herbicide. and drilling was the most-effective way to reduce herbicide injury. The simazine application was the most-effective herbicide, showing the highest forage yield and TDN yield.