• Geotechnical Engineering
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• v.21 no.7
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• pp.35-40
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• 2005

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.428-433
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• 1989

The objective of this experiment was to determine if there were feasible to transplant infant rice seedling for machine transplanting. Cultivars tested were Sobaegbyeo and Daecheongbyeo, ]aponica type cultivars. Infant seedling, young seedling and semi-adult seedling were raised with sailor rock wool in seedling tray from 1986 to 1988. Infant rice seedling raised more than 4 days after sowing with rock wool was uniform, and low in ratio of missing hill at machine transplanting. Tiller number per m$^2$ was more in infant rice seedling, young seedling and semi-adult seedling, in that order. Heading dates were not significantly different among seedlings applied, however rice plant sown directly was later 4 or 5 days than any other seedlings. Panicle number per m$^2$ was more in infant seedling than in semi-adult seedling, but ripened ratio was lower in infant seedling due to lodging. Thus there were not greatly different in yield among seedlings tested. Therefore infant rice seedling (more than 5cm in plumule length) raised for 7 days was most optimum, and rock wool would be used as a nursery soil instead of nursery soil for raising infant rice seedling in machine transplanting.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.400-409
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• 2015

This study examined the plant growth and development characteristics of leafy vegetables on the hydroponic substrates of waste wood chips, radiate pine chips, and mat type of waste wood chips. The bulk density of waste wood chips and radiata pine chips were $0.2g/cm^3$ and $0.16g/cm^3$, respectively. The moisture retention properties of both the radiata pine chips and waste wood chips were found to be similar but not better than those of the control rock wool and coco peat hydroponic substrates. The moisture retention property of the mat type was found to be the lowest. The chemical analysis of waste wood hydroponic substrates (w/v) was as follows.; The pH was 6.59, electric conductivity was 6.76 dS/m, total nitrogen content was 0.5%, C/N ratio was 113%, phosphorus was 10.1 ppm, potassium was 77 ppm, calcium was 531 ppm, magnesium was 49 ppm, and sodium was 96 ppm. The results from the radiata pine chemical analysis showed that it had a pH of 5.29, electric conductivity of 4.49 dS/m, total nitrogen content of 0.32%, C/N ratio of 180%, phosphorus of 6.4 ppm, potassium of 83 ppm, calcium of 97 ppm, magnesium of 29 ppm, and sodium of 59 ppm. Except for the plants grown in mat type, the developmental characteristics of the plants grown in rock wool and coco peat hydroponic substrates were similar. Based on the results of the experiment, waste wood resources may possibly be used as an organic solid medium in place of the existing rock wool and coco peat medium.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.5
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• pp.98-108
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• 2009

The purpose of this study is to analyze the characteristics of limited methods, economics and breeding appropriateness of native and imported ground cover plants in the methodology of a shallow soil rooftop garden. The new shallow soil rooftop gardening method uses a total of 13cm in soil thickness, including 4.5cm of top soil on a 7.5cm rock-wool-mat stacked onto a 1cm roll-type-draining plate. The total construction cost for each method of soil level within the design price standard for SEDUM BLOCK is 89,433won/$m^2$, and for DAKU is 92,550won/$m^2$. By comparing those two methods, the construction cost of the shallow soil artificial foundation methodology is 45,000won/$m^2$; this shows the new method is 50% less expensive than the existing method of shallow soil rooftop gardening. The experiment was executed on the rooftop of the Korean National Housing Corporation to ensure validity of the shallow soil artificial foundation planting, and the sample plants which were imported and grown now in native covering. A list investigating the growing plants was made of the cover rate in each plant class, both while alive and the dry plant weight. The native ground cover plants, Sedum kamtschaticum, Sedum middendorffianum, Allium senescens, Sedum sarmentosum, Aquilegia buergariana, and Caryopteris incana increased the cover rate, live weight and dry weight in the shallow soil artificial foundation method. Among the imported cover plants, Sedum sprium and Sedum reflexum, the cover rate increased and growth conditions improved. However, some species needed weed maintenance. After examination with the less expensive shallow soil artificial foundation method and growth analysis, it was found that rooftop gardens are a low-cost option and the growth of plants is great. This result shows the new method can contribute to the proliferation of rooftop gardens in urban settings.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.198-208
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• 1992

Recently, a nursery mat made from rock wool has realized transplanting of the younger seedlings with the ordinary transplanting machines for Chibyo and Chubyo(3 and 4～5 leaved seedling, respectively). The seedlings defined as the 'Nyubyo' or 'Nursling seedlings' became possible to achieve economic profits from the reduction in both working time and costs. It being widely noticed as a strategy to solve the difficulties in current rice cultivation. The nursling seedlings are 1.4 to 2.5 leaves and height at 4.5 to 7cm, grown 4 to 7 days after seeding. They maintain still up to 50 to 80% of their nutrients in the endosperm, and can grow by using only their own nutrients for a certain period of time after transplanting. Nursling seedlings take 2 days in the nursery chamber at 32$^{\circ}C$ after seeding, and 2 days in the greening house at $25^{\circ}C$. This is only 4 days, all together, to make the nursling seedlings of 1.5 leaves which are ready for transplanting. Watering is only needed once at the sowing time. It only takes 1 or 2 waterings even to raise a seedlings for a period of 7 days. The number of nursery boxes can be reduced because it is possible to sow more densely(220 to 240g per box), thus it only needs seedlings of 15 to 16 boxes per 10 a which leads to a reduction in facilities and space needed. Temperature during the nursery period can be artificially adjusted more precisely which may lead to the prevention of temperature stress. The nursling seedlings can root rapid by because the crown roots from the coleoptile node begin to emerge immediately after transplanting. They show strong resistance to low temperature (12$^{\circ}C$) and deep-planting. There is no danger in the rooting of the seedlings even if half of their height is buried into the soil. Moreover, it can root at a rate of up to 65 to 80% even if the full height of the seedlings is buried. They show also strong resistance to submergence (10～15cm). The nursling seedlings tend to grow by producing tillers from lower nodes. It is therefore, necessary to control to keep the proper numbers of tillers per unit area. They have no fear in the delay of heading and their yield components can be so well balanced that the same level of yield was achieved with the nursling seedlings compared to that with Chibyo. It was further suggested that if the surplus tillers can be avoided by such cultivation practices, the number of grain per panicle can be kept greater and higher yield can be realized. Practical experiments with the nursling seedlings conducted in 1989 and 1990 by farmers in various areas showed exciting results. The nursling seedlings will become widely spread, or at least occupy an important position in Japanese and also in Korean rice cultivation techniques.tivation techniques.