• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.1
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• pp.20-28
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• 1999

Nine soil media when placed over a plastic sheet with three seeding rates were evaluated for influence on covering rate, height, growth, surface hardness, tear strength and sod establishment of Kentucky bluegrass. 1. Bark, peat and vermiculite over a plastic sheet had good effect in terms of the establishment of Kentucky bluegrass sod. 2. The good establishment of Kentucky bluegrass sod grown on bark, peat and vermiculite over a plastic sheet seemed to be caused by physical and chemical properties of each soil medium. 3. Sand, sandy loam, perlite and peatmoss caused poor effects on the covering rate, the growth, and the tear strength of Kentucky bluegrass. 4. Optimum seeding rate was $10g/m^2$ in terms of density and competition. 5. Good quality sod more depended on soil media than on seeding rates in this study.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.393-399
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• 2005

Since vegetations are near the wavelength range in 700nm and have absorbent as well as reflective wavelength ranges, there is a much difference in terms of its reflection rate. There are currently many researches on vegetation index being conducted in order to apply the remote-sensing technology to vegetations rising their characteristics of absorbent and reflective wavelength ranges. Normalized Difference Vegetation Index (NDVI) and Perpendicular Vegetation Index (PVI) have been most commonly used. It is usually the evaporation, carbon-dioxide consumption, and chlorophyll density that represent the activity of vegetation, but chlorophyll density is the most commonly used among them. Since the red wavelength range used to obtain the NDVI and PVI has a strong extinction of chlorophyll, it is also useful to test chlorophyll density. The NDVI, in particular, is used to identify the vegetation conditions summarily, and thus, is suitable for initiative researches. Nevertheless, since these vegetation index produce mixed information of the Vegetation vigor and vegetation cover, it is essential to monitor a wavelength range that is independent from redundancy of the Vegetation vigor and vegetation cover. Although many vegetation indices have evaluated both the vegetation vigor and Vegetation cover simultaneously, this research intends to emphasize the utility of separable evaluations of the Vegetation vigor and Vegetation Cover rate through an experiment with grasses. As a result of evaluating vegetation index using spectral reflectance, a separable evaluation of the vegetation vigor and cover has been found more useful.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.503-511
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• 2013

The purpose of this study was to evaluate temperature reduction and heat budget of extensive modular green roof planted with Sedum sarmentosum and Zoysia japonica. Plant height and green coverage were measured as plant growth. Temperature, net radiation and evapotranspiration of concrete surface, green roof surface, in-soil and bottom were measured from August 2 to August 3, 2012 (48 hours). On 3 P.M., August 3, 2012, when air temperature was the highest ($34.6^{\circ}C$), concrete surface temperature was highest ($57.5^{\circ}C$), followed by surface temperature of Sedum sarmentosum ($40.1^{\circ}C$) and Zoysia japonica ($38.3^{\circ}C$), which proved temperature reduction effect of green roof. Temperature reduction effect of green roof was also shown inside green roof soil, and bottom of green roof. It was found that Zoysia japonica was more effective in temperature reduction than Sedum sarmentosum. Compared with the case of concrete surface, the highest temperature of green roof surface was observed approximately 2 hours delayed. Plant species, temperature and soil moisture were found to have impact on surface temperature reduction. Plant species, air temperature, soil moisture and green roof surface temperature were found to have impact on temperature reduction in green roof bottom. As results of heat budget analysis, sensible heat was highest on concrete surface and was found to be reduced by green roof. Latent heat flux of Zoysia japonica was higher than that of Sedum sarmentosum, which implied that Zoysia japonica was more effective to improve thermal environment for green roof than Sedum sarmentosum.

• Asian Journal of Turfgrass Science
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• v.21 no.1
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• pp.9-21
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• 2007

Research was initiated to examine establishment efficiency of zoysiagrass by plugging. Zoysiagrass is known to be a slowly establishing turfgrass species. Properly-treated zoysiagrass seed can speed up the establishment rate, while initial irrigation practice is intensively required after seeding. A planting method with small plugs($2.5{\times}2.5cm$) from seeding can overcome initial watering requirement. Establishment speed, however, can vary with planting dates, planting spaces, and plastic film cover in early stage. Establishment characteristics were investigated for two years by planting dates that were April 5, May 18, July 13, August 24 and October 29 in 2004 and April 6 in 2005. They were also compared with three different spaces($20{\times}20,\;25{\times}25,\;and\;30{\times}30cm$) and three different fertilizer levels(15, 30, and $45g\;N{\cdot}m^{-2}$). Ground coverage reached to 90% in plugs of 'Zenith' zoysiagrass planted on April 5. It increased suddenly in period of July to August, resulting in about 50% of full establishment rate. Establishment rates were significantly faster over 9% in plugs spaced at $20{\times}25cm$ than in those at $30{\times}30cm$. No significant differences were observed on the stolen number and stolen length in the study. Survival rate in zoysiagrass plug was over 90% at all plantings. These results demonstrated that zoysiagrass establishment using small plug from seeding is considered to be a safe and efficient method.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.191-196
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• 1998

This experiment was conducted to investigate the mulch effect of rice straw and dead water foxtail treated with herbicides on weed germination, seedling establishment, and early growth of rice under the no-till culture condition. The percent seedling establishment of rice straw + dead water foxtail mulch was decreased significantly compared to rice straw mulch and non-mulch. Rice straw mulch and rice straw + dead water foxtail mulch inhibited the early growth of no-till direct seeded rice remarkably. However, they promoted rice growth after active tillering stage. Rice straw mulch and rice straw+dead water foxtail mulch in no-till direct seeding decreased weed occurrence significantly. The control value of barnyardgrass, compared with non-mulch, was 96.5% in the rice straw mulch and 75.6% in the rice straw + dead water foxtail mulch, respectively. The pH and concentration of dissolved oxygen in irrigated water were reduced significantly by both rice straw mulch and rice straw+dead water foxtail mulch during early rice growth stage.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.189-195
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• 2017

This study was conducted to evaluate weed control effect in organic soybean upland field as affected by cover crops including rye, hairyvetch, and its mixture. The experiment was conducted during two years (2015 and 2016) at the NAS (National Institute of Agricultural Sciences) organic farming experimental field. The cover crops were seeded after tillage at fall crop season in 2014, and then, the soybean field was managed with no tillage system from 2015. The weed suppression rates of cover crops application for rye and mixture (rye+hairyvetch) treatment during 60 days after transplanting were 80% and 30%, respectively. However, weed suppression rate of hairyvetch treatment was not significantly different as compared to control. Weed flora in experimental field were less than general soybean field. The average organic soybean yield was generally low compare to normal year, nevertheless, the soybean yield for rye and mixture treatment in 2016 were significantly higher than PE mulching treatment.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.183-187
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• 1992

This study was conducted to evaluate the effect of systematic herbicide application and polyethylene(PE) film mulching in direct seeded Angelica gigas Nakai. Freshly-collected-seed showed 86% of emergence rate and required 18 days of emergence duration. Cold treatment of seeds increased emergence rate by more than 90% and shortened 2 days of emergence duration. Paraquat) 1,1'-dimethyl-4,4'-bipyridylium dichloride was the most effective when applied just before emergence of A. gigas and provided 96% of emergence rate and 91% of weeding effect when applied 23 days after seeding. Soil applied herbicides used did not cause any phytotoxicity on emergence with application of 2-fold recommended rate and gave more than 90% of weeding effect. Black PE film mulching gave excellent emergence rate and weeding effect, and shortened emergence duration by 8 days.

• Korean Journal of Weed Science
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• v.31 no.4
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• pp.355-359
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• 2011

This study was conducted to evaluate the effects of seeding of Vicia tetrasperma and V. hirsuta on the rate of ground cover as well as growth and yield of organic pepper plants in 2008 and 2009. All seeds of both species were gathered from Dangjin, Chungnam in late June of 2006 and stored for two year at room temperature. Capsella bursapastoris, Echinoloa crus-galli, Digitaria ciliaris, and Commelina communiswas were observed as main weeds during the winter and summer, respectively, at the field of V. tetrasperma and V. hirsuta. C. bursapastoris did not affect growth and yield of pepper plants. Seeding of V. tetrasperma and V. hirsuta maintained high percentage of ground cover later in the growing season of pepper plants and reduced significant amounts of weed in 2009. V. tetrasperma and V. hirsuta, therefore, produced more pepper yield compared to that of control but similar yield to the conventional system (polyethylene film).

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.371-379
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• 2010

Crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa) and rye (Secale cereale) are common leguminous cover crops. Because they contain water-soluble allelopathic substances that show a variable level in tissue depending on growth stage of the plants, the weed inhibition effects are dependent on the growth stage of cover crops. This study investigated the allelopathic effects of crimson clover, hairy vetch and rye on soybean, radish, oilseed rape and lettuce seeds germination and seedling growth. We used extract that were prepared from the shoots of crimson clover, hairy vetch and rye at different growth stages, vegetative growth stage, flowering stage, and fruiting stage. Applications of aqueous extracts from three growth stage of cover crops strongly affected to oilseed rape and lettuce seeds germination but the treatment resulted in a slight inhibition of the germination in soybean and radish. Radical length was more sensitive to aqueous extracts than seed germination rate. Especially, three cover crops extracts at vegetative growth stage highly inhibited seedling root growth of oilseed rape and lettuce by over 80% and 90% respectively. Furthermore, the $GR_{50}$ values were lowest in the treatment of extracts from vegetative growth stage and the level of phenolics was decreased by the order of vegetative growth stage, flowering stage and fruiting stage.

• Journal of the Mineralogical Society of Korea
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• v.18 no.4 s.46
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• pp.277-288
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• 2005

Perlite, a hydrated volcanic glass, occurs mainly as a bed-like body, and is distributed intermittently along the unconformity surface between the Beomgockri Group and its lower formations, viz. Janggi Group. The perlite is intimately associated with surrounding pumiceous welded tuff and rhyodacites in space and time. Compared to the typical perlite, the perlite is rather silica-poor and impure, and thus, includes lots of phenocrysts and rock fragments. Nearly the perlite is compositionally rather close to a pitchstone than a perlite in water contents. Petrographic comparison between perlite and associated volcanic to volcaniclastic rocks indicates that pumiceous welded tuff and rhyodacite seem to be Protolith of the Perlite. A Zr/$TiO_{2}$-Nb/Y diagram and field occurrence of perlite and their protolithic rocks also conforms the above interpretation. Kn addition, remnant vesicles in perlite strongly reflect that the precursor of perlitic glass appeared to be pumice fragment as well as volcanic glass. The perlite was diagenetically formed by way of a pervasive water-rock interaction at the deposition of the Manghaesan Formation in lacustrine environment. During perlitization, $SiO_{2}$ and alkali tend to be consistently depleted. Preexisting system of the Beomgockri Group based on the perlite formation should be corrected, because the perlite was formed diagenetically without lateral persistence in its occurrence.