• Korean Journal of Remote Sensing
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• v.20 no.3
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• pp.197-205
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• 2004

Wetlands are lands with a mixture of water, herbaceous or woody vegetation and wet soil. And linear spectral mixture analysis (LSMA) is one of the most often used methods in handling the spectral mixture problem. This study aims to test LSMA is an enhanced routine for classification of wetland land-covers in Paldang reservoir and vicinity (paldang Reservoir) using Landsat TM and ETM+ imagery. In the LSMA process, reference endmembers were driven from scatter-plots of Landsat bands 3, 4 and 5, and a series of endmember models were developed based on green vegetation (GV), soil and water endmembers which are the main indicators of wetlands. To consider phenological characteristics of Paldang Reservoir, a soil endmember was subdivided into bright and dark soil endmembers in spring and a green vegetation (GV) endmember was subdivided into GV tree and GV herbaceous endmembers in fall. We found that LSMA fractions improved the classification accuracy of the wetland land-cover. Four endmember models provided better GV and soil discrimination and the root mean squared (RMS) errors were 0.011 and 0.0039, in spring and fall respectively. Phenologically, a fall image is more appropriate to classify wetland land-cover than spring's. The classification result using 4 endmember fractions of a fall image reached 85.2 and 74.2 percent of the producer's and user's accuracy respectively. This study shows that this routine will be an useful tool for identifying and monitoring the status of wetlands in Paldang Reservoir.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.260-267
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• 2010

As sloped farmland is subject to runoff and soil erosion and consequently require appropriate vegetative coverage to conserve soil and water, a field study was carried out to evaluate the impact of crop canopy coverage on soil loss and runoff from the experimental plot with three different textural types (clay loam, loam, and sandy loam). The runoff and soil loss were examined at lysimeters with 15% slope, 5 m in length, and 2 m in width for five months from May to September 2009 in Suwon ($37^{\circ}$ 16' 42.67" N, $126^{\circ}$ 59' 0.11" E). Red pepper (Capsicum annum L. cv. Daechon) seedlings were transplanted on three different dates, May 4 (RP1), 15 (RP2), and 25 (RP3) to check vegetation coverage. During the experimental period, the vegetation coverage and plant height were measured at 7 day-intervals and then the 'canopy cover subfactor' (an inverse of vegetation cover) was subsequently calculated. After each rainfall ceased, the amounts of soil loss and runoff were measured from each plot. Under rainfall events >100 mm, both soil loss and runoff ratio increased with increasing canopy cover subfactor ($R^2$=0.35, p<0.01, $R^2$=0.09, p<0.1), indicating that as vegetation cover increases, the amount of soil loss and runoff reduces. However, the soil loss and runoff were depending on the soil texture and rainfall intensity (i. e., $EI_{30}$). The red pepper canopy cover subfactor was more highly correlated with soil loss in clay loam ($R^2$=0.83, p<0.001) than in sandy loam ($R^2$=0.48, p<0.05) and loam ($R^2$=0.43, p<0.1) plots. However, the runoff ratio was effectively mitigated by the canopy coverage under the rainfall only with $EI_{30}$<1000 MJ mm $ha^{-1}hr^{-1}$ ($R^2$=0.34, p<0.05). Therefore, this result suggested that soil loss from the red pepper field could be reduced by adjusting seedling transplanting dates, but it was also affected by the various soil textures and $EI_{30}$.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.322-326
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• 2013

Many organic fruit growers adopt cover cropping in their orchards to improve soil properties. A field experiment was conducted to determine the effects of cutting frequency of cover crop (CF) and liquid manure application (LM) on green manure production (GMP) and returnable nutrient content (RNC) in pear orchard. The combined effects of CF and LM were tested at two levels, respectively, with liquid manure ($L_1$) and without liquid manure ($L_0$). After that, cover crops were cut once ($C_1$) and three times ($C_3$) in rye, and twice ($C_2$) and four times ($C_4$) in hairy vetch. The result showed that main factors related to green manure production were different depending on the species. In rye, LM was more effective in increasing the dry weight of cover crop and RNC than CF. In contrast, the parameters were more affected by CF rather than LM in hairy vetch. Thus, it is suggested that different management technique is needed depending on the cover crop species in order to maximize the green manure production in pear orchard.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1018-1031
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• 2010

In order to investigate the applicability and suitability of the industrial by-products to landfill final cover, field pilot-scale lysimeter experiments were carried out. The mixture of loamy soil, bottom ash, and construction waste was placed as a cover material in lysimeter($2m{\times}6m{\times}1.2m$) which were constructed with cement brick, and then, volumetric water contents, pF value, and the quantity of runoff and seepage of treatment boxes filled with the mixture of loamy soil and the industrial by-products were monitored from July, 2007 to February, 2008. Among the cases tested, consequently, the case containing the mixture of bottom ash and loamy soil was most effective in engineering and hydrological properties and water retention ability.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.641-647
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• 2015

This study was conducted to select native ground cover plants for sod culture in an organic apple orchard by estimating the effect of three native ground cover plants, Glechoma hederacea, Thymus magnus, and Ixeris stolonifera, on the soil coverage, time-periodic weed occurrence, fruit characteristics, and soil chemical properties. The plant height of G. hederace, T. magnus and I. stolonifera were 15.0 ㎝, 13.4 ㎝ and 7.2 ㎝, respectively. The dry weight of G. hederace, T. magnus and I. stolonifera were 463 ㎏/10a, 247 ㎏/10a, and 255 ㎏/10a, respectively. The plant height and dry weight of G. hederacea were higher than in the other species. T. magnus and I. stolonifera having relatively lower soil cover rate during their life cycle produced a lot of weeds in the orchard as compared with the control. In contrast, G. hederacea showed 100 percentage of ground cover in the first year, and maintained high percentage of ground cover in the growing season of ‘Tsugaru’ apple for another 2 years. When the soil was covered with G. hederacea in the orchard for 3 years, the amount of weed was only 114 ㎏/10a and number of weeding was also reduced about 33% compared with control as well as the other species. There were no differences in the tree growth and fruit characteristics between the native ground cover plants and the control; however, positive effects of native ground cover plants on soil chemical properties were found. In G. hederacea, available P₂O₄content in soils remarkably increased and was a significant difference among native species. In addition, cation (Ca, Mg and K) content in soils increased by 39% in Ca, 6% in Mg, and 11% in K at G. hederacea compared with control. These results suggest that G. hederacea could be advantageous in terms of reducing the amount of herbicide applied and the labor required for weed control, and controlling soil chemical properties; therefore, it is a good candidate for sod culture in an organic apple orchard.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.15-21
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• 2005

In this study, the utilization of coal-ash and phosphogypsum was considered as the evapotranspiration final landfill cover(ET cover) material. Cover material considered was the mixture of the weathered granite soil, coal-ash and phosphogypsum and so we sequentially performed the leaching test, column test and field model test to investigate the environmental effects of mixtures of coal-ash and phosphogypsum. In the leaching test, all materials had lower heavy metal concentration than the regulated threshold values. The column test and the review of related regulations were carried out to determine the optimum mixing ratio(OMR) and OMR was soil(4):coal-ash(1): phosphogypsum(1) on the volume base, which was applied to field model test. Field model tests were continued from February to June, 2004 in the soil box that was constructed with cement block. It was verified that coal-ash and phospogypsum mixed with soil was safe environmentally and the mixture of both wastes could improve the water retention capacity of cover materials.

• Asian Journal of Turfgrass Science
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• v.16 no.2
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• pp.75-83
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• 2002

The back-filled soil of the New Incheon International Airport construction site was reclaimed with sea sand in near the Young-Jong island. The primary study was carried out from August 1993 to June 1997 to study soil amendment and to select salt resistance turfgrass species. This study dealt with low maintenance area that included most part of open space of airport site. The second experiment, from October 1996 to August 1998, focused on soil amendment and selection of turfgrass species for alongside runway where turf area was maintained. Through two previous studies, propagation methods with zoysiagrass were tested for alongside runway and surrounding areas at 1998. The study of construction methods with zoysiagrass, vegetative propagation showed better results on visual quality and cover rating compare with seeding propagation. However, significant different between vegetative and seeding propagation was not showed on visual quality and drought tolerance after one year of plot establishment. The cover rating by seeding construction methods reached in excess of 70% of limitation suggested by the Incheon International Airport Cooperation. Zoysia net and sprigging net methods were the most suitable where there requires rapid and high rate of ground cover. Seeding propagation should be acceptable to obtain a resonable cover rating where there allows relatively longer period of completion. Therefore, it should be possible to attain a proper rating of ground cover on the site of open space, alongside runway or areas similar to the New Incheon International Airport which is being built on dredged seashore sand. However, the methods of soil amendment, selecting salt tolerance species, and proper construction procedure should be considered at the a time.

• KIEAE Journal
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• v.10 no.3
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• pp.11-16
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• 2010

This paper has attempted to investigate the change in soil moisture volume and temperature of architecture by planting ground(soil thickness and soil mixture ratio) and ground cover plants(Sedum sarmentosum, Zoysia japonica, Chrysanthemum zawadskii) for middle region green roof system. For this, a test was conducted on the roof of Konkuk University building from April 2009 to October 2009. In terms of treatment, five types(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$) depending on soil mixture ratio and two types(15cm, 25cm) by soil depth were created. Results of soil moisture volume by soil mixture ratio in the 15cm soil thickness showed that the difference was significance between simple soil and mixture soil treatment, however, the statistical significance was not recognized according to soil mixture ratio. In case of 25cm soil thickness, soil moisture volume by soil mixture ratio was more higher 7Vol.%~10Vol.% in the mixture soil than simple soil treatment. In terms of districts planted ground cover plants, soil volume moisture differed among plants in the order Zoysia japonica 17.74 Vol.%$34.86^{\circ}C$, district non-planted $27.49^{\circ}C$, Sedum sarmentosum $25.11^{\circ}C$, Chrysanthemum zawadskii $23.08^{\circ}C$, Zoysia japonica $24.45^{\circ}C$ respectively So, concrete surface showed more higher $5^{\circ}C{\sim}15^{\circ}C$ than other things among the all the time. Result of inner temperature of the architecture and soil, it was measured inner of architecture $25.69^{\circ}C$, inner district non-planted $24.29^{\circ}C$, Chrysanthemum zawadskii $23.90^{\circ}C$, Zoysia japonica $24.02^{\circ}C$, Sedum sarmentosum $25.13^{\circ}C$, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.822-828
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• 2012

Organic fruit production has increased due to consumer's interest and government's political support for environmentally-friendly agriculture. The aim of this study was to investigate the effects of cover plants on soil microbial community and establish the fruit cultivation method by organic farming techniques. Cover plants used as an organic nutrient source in an apple orchard were rye and barley, the Gramineae and red clover and hairy vetch, the Leguminosae. In the effects of cover plants on the soil chemical characteristics, the soil pH values were higher than that of conventional organic pear orchard. The content of P showed no significant difference between control and cover plant plots. Organic matter level was similar in control and Gramineae cover plant plots, while organic matter content in cover plants belong to Leguminosae was lower than that of control plot. K content was lower in the plots treated with rye and red clover than control plot, while K content in hairy vetch treated plot was higher than control plot. Ca content was lower in control plot than in cover plant treated plots. Concentrations of Mg in the plots treated with barley and hairy vetch was lower than control plot. In August rye and red clover covered soil showed higher bacterial community density than that of control soil and barley treated soil showed highest Actinomycetes community density among treatments. Barley and hairy vetch soils showed higher level of fungi community density than that of control soil in August. In pyrosequencing analysis barley treated soil showed highest distribution ratio of Actinomycetes among treatment. Our findings might be used as basic data for choosing cover plant with effective organic matter decomposition and nutrition supply capacity.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.50-52
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• 2003

The purpose of this study is to evaluate the hydrological impact due to temporal land cover changes by gradual urbanization of a watershed. WMS HEC-1 was adopted, and DEM with 200m resolution and hydrologic soil group from 1:50,000 soil map were prepared. Land covers of 1986, 1990, 1994 and 1999 Landsat TM images were classified by maximum likelihood method. By applying the model, watershed average CN value was affected in the order of paddy, forest and urban/residential, respectively.