• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.4
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• pp.10-17
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• 2010

The objectives of this study were to compare the growth of Vitex rotundifolia as affected by the difference of soil depth and mixture ratio in a shallow-extensive green roof module system, and to identify the level of soil thickness and mixture ratio as suitable growing condition to achieve the desired plant growth in green roof. Different soil thickness levels were achieved under 7cm, 15cm and 25cm of shallow-extensive green roof module systems made by woody frame of $500{\times}500{\times}300mm$. Soil mixture ratio were eight types for perlite : peatmoss : leafmold = 7 : 1 : 2 (v/v/v, $P_7P_1L_2$), perlite : peatmoss : leafmold = 6 : 2 : 2 (v/v/v, $P_6P_2L_2$), perlite : peatmoss : leafmold = 5 : 3 : 2 (v/v/v, $P_5P_3L_2$), perlite : peatmoss : leafmold = 4 : 4 : 2 (v/v/v, $P_4P_4L_2$), only sand ($S_{10}$), sand : leafmold = 7 : 3 (v/v, $S_7L_3$), sand : leafmold = 5 : 5 (v/v, $S_5L_5$) and only leafmold ($L_{10}$). The growth response of Vitex rotundifolia had fine and sustain condition in $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$., Especially, in case of $P_6P_2L_2$, growth response appeared to be good even in soil thickness 7cm, which showed low survival rates of Vitex rotundifolia in other soil mixtures. Tree height, root diameter, photosynthesis and chlorophyll contents tended to increase with increased soil thickness.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.871-877
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• 2010

The objectives of this study were to compare growth of Pllioblastus pygmaed and soil characteristics as affected by difference of soil thickness and mixture ratio in shallow-extensive green roof module system, and to identify the level of soil thickness and mixture as suitable growing condition to achieve the desired plants in green roof. Different soil thickness levels were achieved under 15cm and 25cm of shallow-extensive green roof module system that was made by woody materials for $500{\times}500{\times}300mm$. Soil mixture ratio were three types for perlit: peatmoss: leafmold=6:2:2(v/v/v, $P_6P_2L_2$), perlit: peatmoss: leafmold=5:3:2(v/v/v, $P_5P_3L_2$) and perlit: peatmoss: leafmold=4:4:2(v/v/v, $P_4P_4L_2$). On June 2006, Pllioblastus pygmaed were planted directly in a green roof module system in rows. All treatment were arranged in a randomized complete block design with three replication. The results are summarized below. In term of soil characteristics, Soil acidity and electric conductivity was measured in pH 6.0~6.6 and 0.12dS/m~0.19dS/m, respectively. Organic matter and exchangeable cations desorption fell in the order: $P_4P_4L_2$ > $P_5P_3L_2$ > $P_6P_2L_2$. $P_6P_2L_2$ had higher levels of the total solid phase and liquid phase, and $P_4P_4L_2$ had gas phase for three phases of soil in the 15cm and 25cm soil thickness. Although Pllioblastus pygmaed was possibled soil thickness 15cm, there was a trend towards increased soil thickness with increased leaf length, number of leaves and chlorophyll contents in 25cm. The growth response of Pllioblastus pygmaed had fine and sustain condition in order to $P_6P_2L_2$ = $P_5P_3L_2$ > $P_4P_4L_2$. However, The results of this study suggested that plants grown under $P_4P_4L_2$ appear a higher density ground covering than plants grown under $P_6P_2L_2$. Collectively, our data emphasize that soil thickness for growth of Pllioblastus pygmaed were greater than soil mixture ratio in shallow-extensive green roof module system.

• KIEAE Journal
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• v.13 no.3
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• pp.105-110
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• 2013

Green roof system is classified as intensive greening, extensive greening or mix of intensive-extensive greening. Recently, light-weigh green roof has been performed actively, because buildings have been considered loads, design and maintenance. This study was conducted to design soil depth for light-vegetation block with using bottom-ash. As a result, it was found that growth of plant had no direct effect on soil depth even it was less than 10cm. Soil depth having under 5cm could be integration of plant roots and vegetation blocks. It was also possible to grow organic vegetables through the experiment of planting. According to this experiment, as light-vegetation block with bottom-ash was used for planting, it makes design shallow soil depth. The results will help install green roof system conveniently not only new buildings but also used buildings.

• Journal of Environmental Science International
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• v.19 no.9
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• pp.1137-1142
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• 2010

This study proposes a guideline of a green roof system suitable for the local environment by verifying the growth of Zoysia japonica in a shallow, extensive, green roof system under rainfed condition. The experimental soil substrates into which excellent drought tolerance and creeping Z. japonica was planted were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$). The plant height, green coverage ratio, fresh weight, dry weight and chlorophyll contents of Z. japonica were investigated. For the soil thickness of 15cm, the plant height of Z. japonica was significantly as affected by the soil mixing ratio and it was shown in the order SL= $P_4P_4L_2$ < $P_7P_1L_2$ = $P_5P_3L_2$ < $P_6P_2L_2$. For the soil thickness of 25cm, the plant height was increased in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was not observed by soil the mixing ratio or soil thickness. However, the green coverage ratio was 86~90% with a good coverage rate overall. The chlorophyll contents of Z. japonica were not significantly affected by the soil mixing ratio in the soil thickness of 15cm, but were higher in the natural soil than in the artificial soil at 25cm soil thickness. The fresh weight and dry weight of Zoysia japonica were heavier in the 25cm thickness than in the 15cm thickness and in the artificial soil mixture than in the natural soil. The result indicated that the growth of Zoysia japonica was more effective in the 25cm soil thickness with artificial soil than in the 15cm soil thickness with natural soil in the green roof system under rainfed condition.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.843-848
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• 2010

This study focused on the characteristics of change soil water with respect to soil thickness and soil mixture ratio, in order to effectively carry out an afforestation system for a roof with a low level of management and a light weight. Soil hardness tended to increase as sand particle was increase regardless soil thickness and soil porosity had more higher artificial soil than natural soil mixture. In case of soil pH, natural soil mixture had between 6.7 and 7.4, and artificial soil mixture had 6.0~6.8. Organic matter, electrical conductance and exchangeable content were highest in $L_{10}$, which it had the highest leafmold ratio. Soil moisture tension(kPa) in 15cm soil thickness was observed natural soil mixture had a considerable change but artificial soil mixture had a gradual change when non-rainfall kept on. In the experimental $L_{10}$, $S_{10}$, $S_7L_3$ and $S_5L_5$ object, the amount of moisture tended to rapidly decrease. However, in the experimental $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ objects, which contained pearlite and peat moss, the amount of moisture tended to gradually decrease. As a result, the use of a artificial soil mixture soil seems to be required for the afforestation of a roof for a low level of management.

• Journal of Environmental Science International
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• v.21 no.3
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• pp.289-296
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• 2012

The purpose of this study was to identify the irrigation intervals and the amount of suitable growing substrate needed to achieve the desired shallow-extensive green roof system during a dry summer in Korea. In terms of treatment, three types (SL, $P_6P_2L_2$, $P_4P_4L_2$) with varying soil mixture ratios and two types (15 cm, 25 cm) with varying soil depths were created. The results have been analyzed after measuring growth and soil water contents. The difference of growth by treatment was significant in terms of green coverage, height, leaf width and photosynthesis. In measurement of chlorophyll content, no difference was detected when measured against soil depth. According to the growth measurement of Zoysia japonica with respect to differing soil mixture ratios in the 15 cm-deep treatment, a statistical difference was detected at the 0.05 significance level in photosynthesis. In case of green coverage, height, chlorophyll content and leaf width, no statistical significance was observed. In case of the 25 cm-deep treatment, a statistical significance was observed in height and photosynthesis. In terms of green coverage, chlorophyll content and leaf width, no statistical significance was detected. In comparisons of soil moisture tension and soil water contents, the irrigation interval and amount were 8 days and 14.9 L in the SL (15 cm) treatment, respectively. The irrigation interval showed for 10 days a 1.3-fold increase, and the irrigation amount was 27.4 L 1.8-fold more than SL (25 cm), respectively. For $P_6P_2L_2$ (15 cm) treatment, the irrigation interval and amount were 12 days and 20.7 L, respectively. However, an irrigation interval under $P_6P_2L_2$ (25 cm) was for 15 days 1.3 times longer than $P_6P_2L_2$ (15 cm), and an irrigation amount of 40 L was 1.9 times more than that under $P_6P_2L_2$ (15 cm). In $P_4P_4L_2$ (15 cm) treatment, it was indicated that the irrigation interval was 15 days, and the irrigation amount was 19.2 L. It was not needed to irrigate for 16 days under $P_4P_4L_2$ (25 cm) treatment during the dry summer and the longest no-rain periods. The irrigation interval and amount under $P_4P_4L_2$ were 1.8-fold and 1.3-fold, respectively, more than SL treatment as affected by soil mixture ratio. Comparatively $P_4P_4L_2$ had more 1.3-fold and 0.9-fold in irrigation interval and amount more than $P_6P_2L_2$. Therefore, it can be noted that different soil depth and soil mixture ratios had a significant effect on the irrigation interval and amount.