• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.3
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• pp.149-155
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• 2020

Cattle feeding in South Korea has been heavily dependent on domestically produced rice straw and imported grain. Around 42% of domestically produced rice straw is utilized for forage, and the remainder is recycled to restore soil fertility. Approximately 35% of round baleages were made with rice straw. However, higher quality hay is desired over rice straw. Due to increasing stockpiles of rice, there has been an economic burden on the government to store the surplus; therefore production of annual forage crops in rice fields has been further promoted in recent years. Hay import from the USA currently constitutes more than 80% of total imported hays. The main imported hays are alfalfa (Medicago sativa), timothy (Phleum pretense), and tall fescue (Festica arundinacea). The estimated forage required for cattle feeding was approximately 5.4 million MT in 2016. Domestically produced forage sates only 43% of that value, while low quality rice straw and imported hay covered the rest of demand by 33% and 20%, respectively. As utilization of domestically produced forage is more desirable for forage-based cattle production, long-term strategies have been necessary to promote domestic production of high quality baleage. One such strategy has been utilizing the fertile soil and abundance of fallow rice fields of western region of S. Korea to produce forage crops. Italian ryegrass (Lolium multiflorum) is the most successfully produced winter annual in the region and is approximately 56% of the total winter annual forage production. Forage sorghums (Sorghum bicolor), sorghum × sudangrass hybrids, and hybrid corn (Zea mays) produce a substantial amount of warm-season forage during summer. Produced forage has been largely stored through baleage due to heavy dew and frequent rains and has been evaluated according to S. Korea's newly implemented baleage commodity evaluation system. The system weighs 50% of its total grading points on moisture content because of its importance in deliverable DM content and desirable baleage fermentation; this has proved to be an effective method. Although further improvement is required for the future of forage production in South Korea, the current government-led forage production in rice fields has been able to alleviate some of the country's shortage for quality hay.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.301-304
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• 2008

The purpose of this study is to embody the integrated working management system for public works, focused on the management of surplus soil at a field of public works. The contents and results of this study can be classified into the design of working management DB for public works and the embodiment of working management DB. First, the design of working management DB for public works consists of three DBs - process management to analyze work plan and performance. for backhoe loader, working management and resources management for equipment and labor management - in connection with work and resources classification system. Secondly, the working management system for public works can describe work plan and performance on a floor plan using graphic. Based on this, the status of process and progress report with visual expression had been developed to facilitate the communications and performance of duties among staff in charge at the field of public works. This study is a specialized system for a company specializing in public works and a system that can be put into practical use if practicality is proved through test-bed with regard to business.

• Korean Journal of Environmental Agriculture
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• v.31 no.2
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• pp.137-145
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• 2012

BACKGROUND: Along with the surplus rice production, introduction of upland crop cultivations into newly reclaimed tidal areas has gained public attentions in terms of farming diversification and farmers income increase. However, its impacts on the surroundings have not been well studied yet, especially associated with nutrient balance from reclaimed upland cultivation. The objective of this study was to investigate water and nutrient balance during winter barley cultivation as affected different fertilization methods. METHODS AND RESULTS: TN and TP balance for three different plots treated by livestock compost, chemical fertilizer, and no application were monitored during winter green barley cultivation (2010-2011) at the NICS Kyehwa experimental field in Jeonbuk, Korea. Nutrient content in soil and pore water near soil surface appeared to increase, while sub-soil layer remained similar with no fertilization plot. Livestock compost application appeared to increase organic matter content in surface soil compared to chemical fertilization. Crop yield was the greatest with livestock compost application (10.6 t/ha) followed by chemical fertilization (6.9 t/ha) and no application (1.8 t/ha). The nitrogen uptake rate was also greater with livestock compost (52.4%) than chemical fertilizer (48.1%). Phosphorus uptake rate was much smaller (about 7.0%) compared to nitrogen. Nutrient loss by surface and subsurface runoff seemed to be minimal primarily due to small rainfall amount during the winter season. Most of the remaining nutrients, particularly phosphate seemed to be stored in soil layer. Phosphate accumulation appeared to be more phenomenal in the plot applied by livestock compost with higher phosphorus content. CONCLUSION: This study demonstrated that livestock compost application to tidal upland may increase barley crop production and also improve soil fertility by supplying organic content. However, excessive phosphorus supply with livestock compost seems likely to cause a phosphate accumulation problem, unless the nitrogen-based fertilization practice is adjusted.

• Journal of Soil and Groundwater Environment
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• v.17 no.2
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• pp.37-46
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• 2012

This study was conducted to identify groundwater recharge and discharge amounts of a representative urban-rural composite area located in Yongin city, Kyounggi-do, Korea. Groundwater recharge would be affected by mainly two processes in the study area: rainfall and leakage from public water pipelines including water-supply and sewage system. Groundwater recharge rate was estimated to be 13.5% by applying annual groundwater level data from two National Groundwater Monitoring Stations to the master regression curve method. Subsequently, the recharge amounts were determined to be $13,253{\times}10^3m^3/yr$. Leakage amounts from water-supply and sewage system were estimated to be $3,218{\times}10^3$ and $5,696{\times}10^3m^3/yr$, respectively. On the whole, a total of the recharge amounts was $22,167{\times}10^3m^3/yr$, of which 60% covers rainfall recharge and 40% pipeline leakage. Groundwater discharge occurred through three processes in the composite area: baseflow, well pumping, and discharge from urban infrastructure including groundwater infiltration into sewage pipeline and artificial extraction of groundwater to protect underground facilities from submergence. Discharge amounts by baseflow flowing to the Kiheung agricultural reservoir and well pumping were estimated to be $382{\times}10^3$ and $1,323{\times}10^3m^3/yr$, respectively. Occurrence of groundwater infiltration into sewage pipeline was rarely identified. Groundwater extraction amounts from the Bundang subway line as an underground facility were identified as $714{\times}10^3m^3/yr$. Overall, a total of the discharge amounts was determined to be $2,419{\times}10^3m^3/yr$, which was contributed by 29% of artificial discharge. Even though groundwater budget of the composite area was identified to be a surplus, it should be managed for a sound groundwater environment by changing deteriorated pipelines and controlling artificial discharge amounts.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.417-422
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• 2003

The objective of this study was to assess the regime of heat shock protein and leaf temperature caused by high temperature stress in chinese cabbage grown in alpine region. In monsoon period, high temperature and heavy rain have caused a stress condition for the cultured higher plants. Chinese cabbages were grown in different altitude, i.e. 600 m and 1,100 m. It was demonstrated that heat shock protein (Hsp 90) in alpine chinese cabbage leaf was actively expressed by high temperature and surplus nitrogen application. As a results of thermo-graphically observed leaf temperatures, chinese cabbage grown in high altitude region were ranged from 20.5 to $24.3^{\circ}C$ while in low altitude from 24.0 to $31.5^{\circ}C$. Furthermore, analysis of assimilated nutrients indicated that total nitrogen content was higher in plant grown under high temperature than under low temperature.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.344-355
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• 2003

Korea is one of those countries that have very high usage rates of chemical fertilizers per unit area of cropland. To reduce the fertilizer application rate, a variety of agricultural polices has been introduced since the 1990s. In this study, fertilizer usage was surveyed on the farm base throughout the country in 1999, and the data were compared with those of 1992. Organic fertilizer application rates were decreased in most cereal crops with time pass, but maintained similar levels in vegetables grown in plastic-film houses and in upland soils. Chemical fertilizer application rates were decreased in most of the cereal crops and vegetables surveyed; however, this reduction was concentrated in phosphate and potassium usage, but not in nitrogen. In spite of this decrease, the fertilizer application levels to most crops were maintained at levels much higher than recommended. In the nutrient balance, which was calculated from the difference between input (chemical and organic fertilizers) and output (agricultural products), the nitrogen nutrient surplus did not decrease; however, phosphate and potassium decreased by 21% and 13%, respectively, in 1999 compared with 1992. To reduce fertilizer utilization and to conserve environment, further reduction of fertilizer application is essential.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.272-279
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• 2003

This study was performed to develop a more rapid and simple nutrient diagnosis method of plants than the conventional leaf analysis method. Cucumber (Cucumis sativus L. cv. jangil banbaek) was planted in the mixed media produced by mixing perlite and rock wool at 1:1 (v/v) ratio. The Yamazakki nutrient solution for cucumber was supplied to the media using micro-drip irrigation system. Experimental plots were consisted of no fertilization, deficient fertilization, adequate fertilization, and surplus fertilization for N, P and K. Specific color difference sensor value (SCDSV) measured by chlorophyll meter was closely related to total-N concentration in leaves measured by the conventional method. Nitrate, $PO_4$ and K concentration in petiole sap measured by test strips showed a significant relationship with total-N, P and K concentration in leaves. Linear regression equations between $NO_3$, $PO_4$ and K concentration in petiole sap and total-N, P and K concentration in the leaves were prepared. Optimum levels of $NO_{3}$, $PO_{4}$ and K in petiole sap were obtained by plugging the optimum concentrations of total-N, P and K in the leaves by other researchers into the equations. In conclusion, the SCDSV measured by chlorophyll meter and the concentration of $NO_3$, P and K in petiole sap measured by the test strips would be suitable for rapid estimation of plant nutrient status.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.499-508
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• 2019

The study was carried out to investigate growth of 48.6-L pot-cultivated 1-year-old 'Fuji'/M.9 apple trees depending on different levels of nitrogen concentration. While rise in tree growth was paralleled with increase of nitrogen concentration, more than 32 mM of nitrogen rather restrained tree growth. In particular, growth of 16 mM of nitrogen treated trees was satisfied with criteria for production of high-quality pot-cultivated nursery stocks. Although mineral contents of leaves were higher in 8 and 16 mM nitrogen treatments than commonly recommended mineral contents in apple orchards, such somewhat surplus minerals could be helpful for tree growth after transplanting to apple orchards. In addition, our result indicated that soils of 8 and 16 mM of nitrogen treated pots met appropriate criteria for soil chemical property of apple orchards. Thus, in the light of tree growth, mineral contents of leaves, and soil chemical property in the pots, 16 mM of nitrogen treatment is considered to be suitable for production of 1-year-old 'Fuji'/M.9 apple potted trees.

• Korean Journal of Organic Agriculture
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• v.14 no.1
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• pp.55-67
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• 2006

A survey of 31 organic farmers were conducted to investigate the actual conditions of organic matter application. The amounts of organic matter application in the fields were higher in order of fruit, vegetable and rice farm. The average was 50 ton/ha in vegetable farms. In the green vegetable farms saw dust and animal manure were mainly utilized to make compost. Rice straw, wood chip, and forest bushes were also used for composting. In the fruit vegetable farms materials relatively lower in nitrogen content such as rice straw and cattle manure were used in vegetative period and materials higher in nitrogen content such as oil cake and wild grass were used in reproductive phase. Nutrient balance investigated in the farm in Icheon region who produce lettuce, angelica, and kale continuously in one cropping year indicated surplus in three major nutrients. Nitrogen and phosphorous were in excess by 29 and 10 kg respectively in the organic rice farm in yang-pyoung region. While soil chemical properties in the organic farms are within the adequate range in open field, it is much higher than the limits in the greenhouse soils. Overall application of organic matter is in an oversupply state. This results suggested that the organic matter management should be based on the soil conditions for sustainable cultivation. Chemical composition of organic matters and soil test reports should be considered prior to the application of organic matter.

• 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.