• Korean Journal of Soil Science and Fertilizer
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• v.50 no.1
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• pp.21-30
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• 2017

The study was performed to determine effective soil depth with crop type. Lysimeters, filled with three types of soils (sandy loam, loam and clay loam), were used. Effective soil depths for 25 cm, 50 cm, 75 cm, and 100 cm were considered for each soil. Six crops were investigated for plant height and yield, and rooting depths: Chinese cabbage, maize, lettuce, potato, red pepper, and soybean. Experiment was conducted at the National Institute of Agricultural Sciences in Suwon from 2012 to 2014. Effective rooting depth including 70% of root ranged from 19 cm to 29 cm for Chinese cabbage, from 24 cm to 38 cm for maize, from 17 cm to 24 cm for lettuce, from 27 cm to 32 cm for soybean, and around 50 cm and 30 cm for potato and red pepper. The maximum depth was 60 cm for soybean, 50 cm for Chinese cabbage, lettuce, and potato, and 75 cm for maize and red pepper. Each crop showed high yield in the treatment with soil depth over maximum rooting depth under all soils.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.183-189
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• 2015

Plant root penetration through soil profile is restricted by compacted layer such as plow pan under conventional tillage. For detecting the compact layer, we made a graduated T-shape probe and measured compared between the depths with rapid change in feeling hardness of hand penetration using T-shape probe and with a rapid increase of penetrometer cone index. On upland crops, including red pepper, corn, soybean and cucumber, plow pan depth ranged from 10 cm to 25 cm depth. The effective rooting depth (ER) had significant correlation with the plow pan depth (PP) except soils with the shallow ground water and/or poorly drained soil. The regression equation was ER = 0.9*PP ($R^2=0.54^{**}$, N = 14) with the applicative PP range of 10-25 cm.

• 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 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.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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.545-553
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• 1993

The metalaxyl seed-soaking treatment markedly increased the root-mat formation of the young rice seedling(8- to l0-day-old) for machine transplanting. This experiment was conducted to find out a possible rooting mechanism of the young rice seedling in relation to the exogenous metalaxyl seed-soaking treatment. The rice seeds of Hwaseongbyeo variety were soaked in the solution of metalaxyl for 24 hours at room temperature. Metalaxyl(25% wettable powder), a fungicide, was used at the concentration of 200ppm as a promoting substance on the root-mat formation of the young rice seedling. Seeding rate of the young rice seedling was 220g per seed tray(30${\times}$60${\times}$depth 3cm). Metalaxyl seed treatment was highly effective in root initiation and elongation of the young rice seedling in terms of root activity, the number and length of root, and amino acid content of roots. The exogenous metalaxyl application would also increase the chlorophyll content and photosynthetic rate in the young rice seedling. Those factors resulted in vigorous root-mat formation of the young rice seedling. In particular, alanine is a lead compound of metalaxyl which biochemically plays an important role in energy intermediate of the rice plant. Alanine conjugation with a glucose (N-${\beta}$-glucoside) is probably the mechanism in enhancement of initiation and elongation of rice roots of young rice seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.34-44
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• 1989

The stability of rice cultivation in Korea is largely depended on climatic conditions, especially, low temperature at the period of early growth stage and after heading. The improvement of cold tolerant varieties and appropriate cultural practices in rice are very effective to minimize the cold damage. This paper is summarized the mechanism and counterplans of cold injury of rice plants. The paddy area having commonly cold injury in Korea is approximately 15, 522ha in 1,709 sites on the national scale. The cold damage at seedling stage in nursery bed appeared to poor germination, leaf discoloration, dead seedlings and seedling rot ect.. At the vegetative stage, the decreased tiller number due to poor rooting and the delayed heading caused by slow growth and panicle differentiation are commonly showed. The cold injury at early reproductive stage appeared to the degeneration of spikelets and rachis - branches, while that at meiosis stage showed to increased sterility due to poor development of pollen and shortened panicle length with delaying heading, therefore the grain yield is largely decreased. The cold damage at heading and ripening stages showed to poor pollination and fertilization, low panicle exsertion, poor grain filling and finally grain quality became low. To minimize the cold injury to rice plants by low temperature, following counterplans would be recommonded ; Improvement of the cold toelrant rice varieties for the regions of midmountains and alpines. Raising healthy seedlings at upland nursery beds and by using of growth regulators such as ABA, Fuchiwang and Tachiace. Soil improvement and organic matter application to reduce cold damage by increasing water and fertilizer holding capacities in the paddy field having commonly cold water and in the place where cold damage is regularly occurred. Appropriate fertilization for raising healthy rice plants to tolerate under low temperature condition. Water management to increase water temperature in the paddy such as depth watering, round channels and polyethylene tubes around the field. Establishment of the optimum cultivation time of rice based on minimum, mean and maximum temperatures at different regions with appropriate rice varieties.