• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.394-399
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• 2011

This study evaluated the effect of using waste nutrient solution (WNS) and reclaimed wastewater (WW) on the growth of Chinese cabbage and soil quality. The pH and electrical conductivity (EC) values of waste nutrient solution were 6.3 and $1.5dS\;m^{-1}$ and being 6.8 and $0.4dS\;m^{-1}$ in reclaimed WW, respectively. WNS found to be included more than $10g\;m^{-2}$ of $NO_3^-$, $K^+$, $SO_4^{2-}$ and $Ca^{2+}$, thereby enhancing Chinese cabbage growth. However, $Cl^-$ and $Na^+$ contents were higher than other nutrients in WW. Among the three irrigation resources, no significant differences were found for the growth of Chinese cabbage plants. On the other hand, pH was decreased in WNS-treated soil when compare to that in WW-treated soil which pH was increased. In spite of the uptake of nutrients by the growing plants, irrigation of the WNS led to an increase in available $P_2O_5$ and exchangeable cations such as $K^+$ and $Mg^{2+}$ in the soil when compared to soil that irrigated by groundwater or WW. Taken together, the use of WNS can remarkably reduce the amount of the chemical fertilizer for Chinese cabbage production; however, WNS can possibly cause a problem as nutrients accumulation in soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.195-203
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• 1986

In order to clarify the trend of change in mineral nutrients in rice plant on various ripening process, P$_2$O$\sub$5/, K$_2$O, MgO, CaO, SiO$_2$ and ash contents were determined for the grain, internode, leaf-5heath and leaf blade respectively for 9 times at an week interval after heading. Four rice cultivars with different maturity and ecotype were grown under normal cultural conditions for the trial. The contents of mineral nutrients in the brown rice were in the order of Ash, P$_2$O$\sub$5/, K$_2$O and MgO. CaO and SiO$_2$ were found in minute quantity in the brown rice. The hull contained SiO$_2$ in large quantity, and it also contained the mineral nutrients in the order of K$_2$O, P$_2$ O$\sub$5/O. The CaO content of hull was extremely minute.

• 농업기술회보
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• v.47 no.1
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• pp.33-34
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• 2010

최근 화학비료의 가격이 올라 농가경영에 부담이 될 뿐만 아니라 2012년 이후에는 가축분뇨의 해양배출을 전면 금지해야 하는 시점에서 농경지에 가축분뇨 액비의 환원은 매우 중요한 해결방안이 될 수 있다. 가축분뇨 액비를 농경지에 환원하면 직물에 양분공급, 토양 비옥도 증가 및 토양생물의 활성유지 등 다양한 효과가 있다. 그러나 필요량 이상으로 사용하면 작물이 웃자라 쓰러져 수량감소와 품질저하는 물론 생산기반인 토양과 수질 등 환경에 나쁜 영향을 초래할 수가 있어 사용기준을 잘 지켜야 한다.

• Vending industry
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• v.5 no.2 s.14
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• pp.32-40
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• 2005

한마디로 ‘토네이도’같은 위력이라 하겠다. 거침없는 임대 미니 커피자판기의 일대 광풍이 자판기산업의 지축을 뒤흔들고 있다고 할 만큼 거세다. 거부할 수 없는 임대 미니 커피자판기의 대세 앞에 기존 자판기 판매시장은 맥을 못 추고 있다 할 만큼 부진을 보이고 있다. 임대시장의 그 막강한 위력은 이제 제어할 수 있는 단계를 지났다. 판매시장과는 상호보완적인 관계에 있는 이 시장은 이미 시장니즈에 의해 자연적으로 굴러가는 성숙기 단계에 접어들었다. 싫든 좋든 판매시장과 임대시장으로 양분된 현실 앞에 기존 판매시장의 새로운 생존전략 강구와 분발이 절실히 요구되고 있다. 금호 기획특집에서는 단기간 안에 무차별적인 확산을 한 임대 미니커피자판기 시장 현황을 집중 조명하는 시간을 마련했다.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.102-108
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• 1991

A field experiment with microplots(D.20cm, L. 85cm) was conducted to obtain quantitative information on the downward movement of nutrients applied to the soils by different amount of irrigation water. The microplots were installed by embedding PVC column(D. 20cm, L. 90cm) filled with sieved soils in the field. Urea, fused and superphosphate, and KCl were broadcasted over the soil in the microplots and surface layer was covered with lime-amended soils. Microplots were removed 1 week after water application and analysed for Cl, $NH_4$ and $NO_3-N$, Bray 1-P and exchangeable cations of Ca, Mg, and K in each segment. Effect of irrigation rate on the movement of these ions were evaluated with the mean downward movement(MDM) determined with nutrient concentration of each segment and the distance to the segment from the site fertilized. For the nutrient studied, MDM was linearly related to the amount of water applied. When one pore volume of water needed for 0.1 bar soil moisture tension was applied, MDM(cm), computed as the piston front of applied water advanced 10cm, was found to be in the order; Cl, 7.52>Inorganic N, 6.03> K, 3.50> Mg, 2.69>Ca, 1.19>P, 0.29. After the downward movement of applied nutrients soil pH seemed to decrease with irrigation in the surface layer(0-15cm) and increase in the subsurface layer. It was also found that ammonium-nitrogen evolved from urea hydrolysis was more effective in raising the subsoil pH rather than the exchangeable Ca and Mg.

• Environmental and Resource Economics Review
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• v.18 no.3
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• pp.431-455
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• 2009

This study estimates the WTP for the plan of solving deforestation due to limestone mining and calculates that damage cost using contingent valuation method. As the results of analysing a dichotomous choice CV data, the yearly mean WTP per household for the plan is 5,045 won(95% confidence interval : 3,729~6,360 won) in single bounded CV model and is 4,361 won(95% confidence interval : 3,710~5,012 won) in double bounded CV model. The damage cost of deforestation due to limestone mining can be estimated as 55.3% of WTP for the plan which is assigned to restoring the deforestation area to the original or similar alternative state. The average yearly deforestation cost of 1 ha due to limestone mining is reached 20.90 million won(95% confidence interval : 16.53~25.27 million won). And the asset value of that 1 ha damage is 160.02 million won(95% confidence interval : 126.56~193.49 million won). The fact is found that the damage cost of deforestation using replacement cost method is likely to be underestimated. The total damage cost of deforestation because of limestone mining in 3 cities (Donghae, Samcheok, Yeongwol) is 204.0 billion won(95% confidence interval : 161.4~246.7 billion won) which is composed of 26.5% for Donghae, 28.9% for Samcheok, and 44.6% for Yeongwol according to the damage size of deforestation due to limestone mining in 3 cities.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.949-954
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• 2012

This study is conducted to evaluate the effects of chelating agents for improving plant growth and reusing accumulated nutrients in soils of plastic film house. Two experiments were carried out at follows: i) The incubation test was conducted using soils treated with 0, 300 mM of EDTA and DTPA to examine the availability of nutrients. ii) For the pot test, chinese cabbages were cultivated in soils with 0, 0.1, 0.5, 1, and 5 mM of EDTA and DTPA to examine the impacts of plant growth response. The application of chelating agents increased ther availability of soil nutrients in the following order: DTPA > EDTA > control. Inorganic concentration of chinese cabbages in DTPA treatments consderably increased in nitrogen, phosphate, iron and aluminium contents than that of the other treatments. The optimal concentration of DTPA for vigorous plant growth as 0.5 mM. Thus, DTPA was more effective than other chelating agents for healty growth of cabbages and the availability of nutrients accumulated in plastic film house.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.253-263
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• 2002

To test for the effect of applied fertilizer and nutrients on uptake and transport for paddy rice, two paddy field trials were conducted with Dongjinbyeo in degenerated salt paddy field of Jeonbuk series from 1999 to 2000. After experiment, soil acidity, content of organic matter phosphate, silicate, potassium, calcium, and total nitrogen was increased by application of fresh cattle manure(FCM). Content of Nitrogen in soil layer leached inorganic nitrogen $NO_3$ was higher that that of $NH_4$ and was high in treatment of FCM. Content of $PO_4$ was higher in FCM than other treatments. But content of potassium was in high control. During the growth of rice plant, the amount of water consumption was 477mm. The amount of supplied nitrogen was high in treatment of no nitrogen(NN), 20% reduced application of LCU(LCU-20%), and no fertilizer. In case of phosphate, the supplied amount was more than the consumed amount with the exception of treatment "no phosphate(NP) and no fertilizer(NF)". In case of potassium, the consumed amount was more than the supplied amount in all treatments. The amount of applied nitrogen in the nutrient infiltrated water was high in treatment soil test(ST), C+FCM+Si(Silicate) and the ratio of recovered nitrogen was high in 20% reduced application of LCU. The amount of applied phosphate in the nutrient infiltrated water was high in FCM and that of applied potassium was high in 20% reduced application of LCU. Nitrogen use efficiency of paddy rice was high in 20% reduced application of LCU and use efficiency of phosphate and potassium was high in C+Si(Silicate). Grain yield of rice was high in order of 20% reduced application of LCU>C+Si=C+FCM+Si>C+FCM.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.309-314
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• 1994

Population changes of serveral bacterial groups and chemical changes of nutrients applied were compared between soils suspensed with pentachlorophenol(PCP) and amended with different nutrients. The number of total bacteria and Gram-negative bacteria were dramatically increased for 1st week, after remained at its maximum level for a short time, decreased gradually in all treatments for 5th week, the rate of decrease were faster at addition of only PCP than at addition of nutrients and PCP. While, the addition of nutrients in the soil suspension containing PCP suppressed the number of PCP-degrading bacteria. The dissipation of PCP were faster at single addition of PCP than at the combined addition of nutrients with PCP. The nutrients added with PCP were rapidly degraded for 1st week, among the nutrients the rate of degration of glucose was faster than that of glutamic acid or glycine. pH values in the suspension showed which addition of nutrients with PCP caused its changes in comparsion with addition of only PCP where changes was slightly.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.683-689
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• 2012

This research was carried out to investigate the effect of installation spacing of subsurface drip irrigation pipe on the mineral content, nutrient uptake, yield of lettuce, water requirement for irrigation, and soil chemical properties in greenhouse cultivation. Semi-forcing and retarding culture were implemented in this experiment, with four treatments containing overhead spray irrigation and three subsurface irrigation lateral spacing intervals of 30, 40, 50 cm at a depth of 30 cm from soil surface, respectively. Each mineral content of lettuce grown under subirrigation system did not show significant difference between treatments, however the uptake of nutrients was lower at 50 cm-distance. The yield was largest in 30 cm-subirrigation (SI), followed by 40 cm-SI, overhead spray, and 50 cm-treatment. Water requirement for irrigation was highest in overhead spray, and it was in reverse proportion to the distance of irrigation pipes. $NO_3$-N content in the soil, at a depth of 10 cm, showed a higher value in 50 cm-SI, followed by 40 cm-SI, overhead spray and 30 cm-SI. Exchangeable K content was highest in 50 cm-SI, Mg was highest in 40 cm-SI, and Ca was lowest in 30 cm-SI. In conclusion, the lettuce yield was not different between 30 and 40 cm-SI, but water requirement for irrigation was lower as the distance of irrigation pipes was further. And it seems to be needed more precise research on this theme, because crop yield and the dynamics of soil minerals in subsurface irrigation can vary with the depth and distance of irrigation pipes, dripper, water flow depending on the soil texture, and plant response to soil minerals.