• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.475-481
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• 1996

This study was carried out to acquire the basic information of root growth under different pot size, imposing different space limitation on rhizosphere. Different size of pots that had same surface area but different depth, 5cm(Iength)$\times$5cm(width)$\times$30, 15, 5cm(depth), were used during the seedling stage of tobacco plant. Space limitation on rhizosphere affected not only the aerial growth, stem height, leaf area and shoot dry weight, but also root growth and root architecture. Aerial growth was highly related to growth of underground part, so space limitation on rhizosphere decreased aerial growth. Limitation on pot volume by reducing pot depth induced new rooting on crown. Root number and relative multiplication rate were higher in small pot that had 5cm depth than large pot, but total root length and mean extension rate showed reverse patterns. Root numbers of 1st order and 2nd order were increased as pot depth was increased, but the root number of 3rd order was increased in small pot. Root system of seedling grown in large pot distributed more horizontally than that in small pot at 20 days after temporary planting (DAT), but the root architecture of seedling was reversed at 25 DAT.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.564-569
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• 2015

In highland crop fields, saprolite is piled up approximately every three years as deep much as 20 to 30 cm because farmers expect that adding new materials may improve productivity and mitigate hazards by continuous cultivation of a single crop. Piling saprolite, however, has been reported to induce poor soil drainage. Effects of deep ploughing with a spading machine and an excavator were studied in sites located in Daekwanryeong-myeon, Pyeongchang in which soil physical properties were deteriorated by piled saprolite. The soil made of parent material of Samgag series was piled up over surface soil of Haggog series naturally developed in the area. Carrot was cultivated in the field. Productivity and growth factors of carrot were compared among control and deep ploughing by a spading machine and an excavator. Effective soil depth extended to 60 cm or greater by 60 cm deep ploughing by an excavator or 50 cm deep ploughing by a spading machine. On the other hand, effective soil depth was within 50 cm at control plot. Productivity of carrot responded to amelioration of soil physical properties. The productivity was greater in deep ploughing treatments than that of control or 30 cm ploughing. It suggested that increased productivity by deep ploughing was mainly related to breaking plough pan which inhibited extension of rooting zone.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.6
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• pp.75-83
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• 2004

Focusing on native plants that have high possibility of being introduced as rooftop material, this study was conducted to investigate extensive and easy-to-manage rooftop garden and to raise the utilization of native plants by verifying their growing response to artificial substrate soil depth and irrigation period. The study was conducted from March to September in 2002. Plants tested included Chrysanthemum zawadskii, Sedium middendorffianum, Thymus quinquecostatus, Allium senescens, and Dianthus superbus. Regarding soil depth, it was 5 cm and 10 cm. Irrigation period was non-irrigation, 1-week, 2-weeks, and 3- weeks, Its result is as follows; 1. In case of Sedum middendorffianum Maxim, mortality rate was 0% regardless of soil depth and irrigation period making it very suitable material for rooftop garden. 2. In case of Allium senescens L., mortality rate was 0% regardless of soil depth and irrigation period making it very suitable material for rooftop garden. Therefore, Provided that fertilizing is managed well, it is a plant that can be highly utilized.3. In case of Chrysanthemum zawadskii Herb. Subsp. (Nakai) Y. Lee Stat., the growth of top was lower in 10cm than in 5cm and it grew well in 10cm. When utilizing for rooftop garden, it would be desirable to keep minimum viable soil depth at over 10cm. If there is enough rainfall, soil and soil depth seem to have greater effect on growth than irrigation period does. 4. In case of Diauthus superbus L. var. longicalycinus (Maxim) Williams, rooting rate and growth were better in 10cm than in 5cm. Therefore, it is desirable to keep minimum soil depth at over 10cm. 5. In case of Thymus quinquecostatus Celak, the growth of top and flowering were better in 10cm than in 5cm. Therefore, it seems desirable to have minimum viable soil depth to be over 10cm. In conclusion, the most suitable species for rooftop garden are Sedium middendorffianum and Allium senescens in this experiment. However, Chrysanthemum zwadskii, Thymus quinquecostatus, and Dianthus chinensis also can be utilized greatly when irrigation is managed regularly in artificial mixed soil over 10cm.

• Journal of Korean Academy of Nursing
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• v.42 no.1
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• pp.36-47
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• 2012

Purpose: This study was to explore adaptation experience to family among women who immigrated for marriage. Specific aims were to identify problems immigrant women face as family members and how they interact with other family members. Methods: Grounded theory methodology was utilized. Data were collected from iterative fieldwork with individual in-depth interviews from 6 immigrant women as key informants, and 2 of their husbands and 2 of their mothers-in-law as general informants. Results: Through constant comparative analysis, a core category emerged as "tearing down the wall in communicating". Causal conditions were feeling frustrated in one's expectations, differences in language and life style, differences in recognition, and perceptions of discrimination and prejudice. Strategies were learning the Korean language, learning Korean culture, managing stress, mediating differences between family members, and introspecting. Intervening factors were support systems, burdens of child-rearing, and the condition of one's health. Consequences were rooting oneself in one's family and accepting one's life as it is. Conclusion: Results of the study indicate that there is a need for nurses to understand differences in communication with family members among immigrant women and to provide information and emotional support to improve the adaptation of these women to their Korean families.

• Journal of Environmental Science International
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• v.25 no.12
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• pp.1689-1699
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• 2016

The growth conditions of planted trees, invasion of nuisance herbaceous species, competition between species, and effects of erosion control were monitored over five years in a riparian greenspace in Gapyeong County that was established through multilayered and grouped ecological planting. Of 156 trees planted in the upper and middle layers, 5.8% died. This tree death was attributed to poor drainage or aeration in the rooting zone from the clay-added root ball and too deep planting as well as a small-sized root ball and scanty fine roots. Of all the trees, 21.6% grew poorly due to transplant stress in the first year after planting, but they started to grow vigorously in the third year. This good growth was largely associated with soil improvement before planting, selection of appropriate tree species based on growth ground, and control of dryness and invasive climbing plants through surface mulching and multilayered/grouped planting. Mixed planting of fast-growing species as temporary trees was desirable for accelerating planting effect and increasing planting density. Thinning of fast-growing trees was required in the fifth year after planting to avoid considerable competition with target species. To reduce the invasion of herbaceous and climbing plants that oppress normal growth of planted trees, higher density planting of trees (crown opening of about 15%), woodchip mulching to a 10-cm depth, and edge planting 2 m wide were more effective than lower density planting (crown opening of 70%), no surface mulching, and no edge planting, respectively. This reduction effect was especially great during the first three years after planting. Nuisance herbaceous plants rarely invaded higher density planting with woodchip mulching over the five years. Higher density planting or woodchip mulching also showed much greater erosion control through rainfall interception and buffering than lower density planting with no mulching did. Based on these results, desirable planting and management strategies are suggested to improve the functions of riparian greenspaces.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.42-59
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• 2017

To investigate rooting and community forming ability, sod strips of Gramineae such as Miscanthus sacchariflorus (Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg., and Arundinella hirta(Thunb.) Tanaka were planted horizontally at a width of 10~15cm in October 2010 on the bank slope of Kwangju Stream in Korea. Seeds of each species were sown in April 2010 in plastic seedbeds(60cm length ${\times}$ 30cm width ${\times}$ 5cm depth) filled with 4cm of garden soil and grew until October 2010 to form rectangular sod, which then was cut into multiple strips(20cm length ${\times}$ 6cm width ${\times}$ 4cm root depth). Weeds growing on the experiment sites were removed twice a year until those four species had formed a community by 2013. Weeds were not eradicated during 2014 and 2015 to observe whether the community formation can be maintained without weed removal. t-tests on stem numbers and heights in May, July, and September were conducted between 2013 and 2014, and between 2014 and 2015. Stem numbers and heights of the four species in 2014 were significantly decreased(p<0.001) compared with those in 2013 due to weed damage to their growth in 2014. Stem numbers and heights of Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. in 2015 were similar to those in 2014(p>0.05). Stem numbers and heights of Arundinella hirta(Thunb.) Tanaka in 2015, however, were significantly reduced compared with those in 2014(p<0.001) due to weed impact on its growth. After three years of weed removal, a community of each species was formed. Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. were able to establish communities without any further weed removal. Arundinella hirta(Thunb.) Tanaka, however, was not able to maintain its community due to considerable damage to its growth caused by weeds even after three years of weed removal. Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. are more suitable to sod strip plantings on stream bank slopes in terms of the maintenance of community formation without weed eradication. t-test on stem numbers and heights each September during the five year experiment period between sod strip planting and potted plants of the four species were conducted. Stem numbers of strip sod plantings were significantly higher(p<0.001) than those of potted one. Heights of strip sod plantings, however, were significantly lower(p<0.05) than those of the potted samples. Therefore, strip sod planting is more advantageous regarding bank slope erosion protection due to the higher number of stems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.219-227
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• 1993

Broadcast-seeded rice in submerged paddy frequently lodge in the field. In general, the causes of lodging in rice cultivation differ with different cultural methods. This study was conducted to investigate the causes of lodging in broadcast-seeded rice (BSR) and hand-transplanted rice (HTR) under four nitrogen (N) levels. Lodging in BSR was mainly a root lodging due to shallow root distribution, while that in HTR showed a bending type owing to deep rooting system. At the upper soil layer (0-5cm from the surface of ground) the root distribution of BSR (65.2%) was much larger than that of HTR (51.6%), whereas at the 5-10cm soil layer the root distribution of BSR (18.5%) was much smaller than that of HTR (28.0%). The depth of buried culm base was much shallower in BSR (1.2cm) than in HTR (4.0cm). The plant height, fresh weight, lodging index, culm diameter and thickness in HTR were much greater than those in BSR, and the breaking strength of lower internode was similar in the two cultivation methods indicating that HTR would have more lodging causes than BSR. In spite of . the more advantages to lodging resistance in BSR it severely lodged in the field. The main lodging-inducing factors of BSR were the shallow root distribution and shallow depth of buried culm base. Besides these, the higher ratio of gravity center of culm was an important factor. This result suggested that for the fundamental prevention of lodging in BSR, an ideotype of rice plant with ' a deep-rooted behavior ' should be developed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.484-489
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• 2003

It is well known that root distribution of rice is a crucial factor for nutrient absorbtion and affect by soil fertility management. However, the findings on root distribution are limited due to laborious and tedious work. The characteristics of root distribution were investigated in long-term fertilizer experiment plots that were established in paddy soil, a fine silty family of typic Hal-paqueps (Pyeongtaeg series) in 1967. fertilizer experiment plots of no fertilizer, compost, NPK and NPK+compost plot have been maintained consistently for the past thirty six year and Npk+silicate plot for the past twenty two years. In NPK plot, 150kg N (urea), 100kg -$\textrm{P}_2\textrm{O}_5$ (fused phosphate) and 100kg $\textrm{K}_2\textrm{O}$(potassium chloride) per hectare have been applied. For NPK+silicate plot, 500kg $\textrm{Si}\textrm{O}_2$ (silicate) was applied in addition to fertilizer in NPK plot. For the compost plot, 10,000kg rice straw compost per hectare were applied. Root samples were taken from the positions of hill-center (below hill) and mid-point of four adjacent rice hills at heading stage by cylinder monolith (CM) method. The soil cores were sampled 20cm depth from the soil surface and partitioned four into layers at an interval of 5cm. The soil particles surrounding roots were washed out with tap water, Length and weight of the roots in each soil layer were measured and root length density (RLD), root weight density (RWD), specific root length(SRL) and rooting depth index (RDI) were calculated. Total root length was measured by intersection method. Plant height, tiller and shoot dry weight were the highest in NPK+compost plot. But RLD of hill-center soil cores was the highest in no-fertilizer plots. In the soil cores from mid-point position of four adjacent hills, RLD at 15-20cm soil depth was higher in compost plot than NPK plot. RLD in compost plots showed even distribution compared to those in chemical- fertilizer plots. RWD was the highest in the NPK+compost plot. SRL was the lowest in the NPK+silicate plot. RDI was the highest in the compost plot. Also, in this experiment it was found that the distribution of roots was closely related to the physical properties of the soil as affected by fertilization management.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.321-321
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• 2017

Water availability in rainfed lowlands (RFL) is strongly affected by climate change. In RFL, rice plants are exposed to soil moisture fluctuations (SMF) but rarely to simple progressive drought as widely believed. Typical RFL field is characterized by a about 5-cm thick high bulk density hardpan layer underneath the cultivated layer at about 20 cm depth that impedes deep root development. Root system has the ability to develop in response to changes in SMF, known as phenotypic plasticity. We hypothesized that genotypes that can adapt to RFL have root plasticity. The roots can sharply respond to re-wetting after drought period and thus penetrate the hardpan layer when the hardpan is wet and so becomes relatively soft, and thus access water under the hardpan. This study aimed to identify CSSLs derived from a cross between Sasanishiki and Habataki which adapted to such RFL conditions. We used 39 CSSLs together with the parent Sasanishiki, which were grown in hydroponics and pot under transient soil moisture stresses (drought and then rewatering), and compared with continuously well-watered (WW) (control) up to 14 days after sowing (DAS), and 20 DAS, respectively. Based on the results of hydroponics and pot experiments, we selected a few lines, which were grown in the soil-filled rootbox with artificial hardpan layer and without artificial hardpan. For the rootbox without artificial hardpan, plants were grown under WW and transient soil moisture stresses for 49 DAS. While the rootbox with artificial hardpan, the plants were grown under WW (control) and SMF (WW up to 21 DAS, 1st drought (22-36 DAS), rewatering (37-44 DAS), and followed by 2nd drought (45-58 DAS)). Among the 39 CSSLs, only CSSL439 (SL39) consistently showed significantly higher shoot dry weight (SDW) than Sasanishiki under transient soil moisture stress conditions as well as SMF conditions in all the experiments. Furthermore, under WW, SL39 consistently showed no significant differences from Sasanishiki in shoot and root growth in most of traits examined. SL39 showed significantly greater total root length (TRL) than Sasanishiki under transient soil moisture stress, which is considered as phenotypic plasticity in response to rewatering after drought period. Such plastic root development was the key trait that effectively contributed to root elongation and branching during the rewatering period and consequently enhanced the root to penetrate hardpan layer when the soil penetration resistance at hardpan layer reduced. In addition, using the rootbox with artificial hardpan layer ($1.7g\;cm^{-3}$, heavily compacted), SL39 showed greater root system development than Sasanishiki under SMF, which was expressed in its significantly higher TRL, total nodal RL, and total lateral RL at hardpan layer as well as at below the hardpan layer. These results prove that SL39 has plasticity that enables its root systems to penetrate hardpan layer in response to rewatering. Under SMF, such root plasticity contributed to its higher gs and Pn.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.98-111
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• 2015

Urban environmental problems such as flooding, depletion of ground water, pollution of urban streams and the heat island effect caused by urban development and climate change can be mitigated by the improvement of the urban water cycle. For the effective planning of water cycle management it is necessary to establish aerial Hydrotope Maps, with which we can estimate the status and change of the water allowance for any site. The structure of the German water balance model BAGLUVA, which is based on soil and vegetation, was analyzed and the input data and boundary condition of the model was compared with Korean data and research results. The BAGLUVA Model consists of 5 Input categories (climate, land use, topography, soil hydrology and irrigation). The structure and interconnection of these categories are analyzed and new concepts and implementation methods of topographic factor, maximum evapotranspiration ratio, effective rooting depth and Bagrov n parameter was compared and analyzed. The relation of real evapotranspiration ($ET_a$)-maximum evapotranspiration ($ET_{max}$) - precipitation (P) was via Bagrov n factor represented. The aerial and land use oriented Hydrotope Map can help us to investigate the water balance of small catchment areas and to set goals for volume of rainwater management and LID facilities effectively in the city. Further, this map is a useful tool for implementing water resource management within landscape and urban planning.