• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.266-272
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• 1999

Aboveground biomass and nutrient contents of a 31-year-old pitch pine(Pinus rigida) and a 31-year-old Japanese larch(Larix leptolepis) plantations were measured in the Chungbu Forest Experiment Station, Kyunggi Province. Aboveground biomass was 170.2ton/ha in the pitch pine and 87.2ton/ha in the Japanese larch plantations. Aboveground biomass difference between both plantations was due to the difference of stand density. Aboveground biomass in both plantations was allocated as follows : stemwood>branch>stembark>needle. The concentrations of all nutrients(N, P, K, Ca, Mg) were generally higher in the Japanese larch needle than in the pitch pine because of high nutrient uptake characteristics of larch compared with pine tree species. The nutrient concentration in different tree tissues in both tree species decreased in the order of needle>branch>stembark>stemwood. Nutrient contents of aboveground biomass were : N, 335.9 ; P, 40.4 ; K, 121.4 ; Ca, 188.6 ; Mg, 93.8kg/ha in the pitch pine plantation, while nutrient contents in the Japanese larch plantation were : N, 226 ; P, 11.5 ; K, 72.9 ; Ca, 75.7 ; Mg, 37.1kg/ha. The nitrogen use efficiency calculated as the biomass produced by one unit of nitrogen was higher in the pitch pine than in the Japanese larch plantations. This result suggests that pine with high nitrogen use efficiency could be adapted in lower site productivity area compared with larch tree species.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.161-170
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• 2017

To investigate the influence of long-term organic cultivation on soil characteristics, chemical properties of 35 soils in the national scale organically managed over 10 years were analyzed. 57% of soils which were managed by the materials containing livestock manure have higher nutrient concentration than the materials not containing livestock manure. The decomposed composts (containing livestock manure) had higher amount of $P_2O_5$, CaO, $K_2O$ than organic fertilizers (not containing livestock manure). In the results, the nutrient concentration of soils in long-term organically managed was higher than optimum range of upland soil, especially pH 6.9, available phosphorus (Av. $P_2O_5$) 744 mg/kg, exchangeable calcium $9.4cmol_c/kg$, potassium 2.51 cmolc/kg. On the other hand, more than 50% of soils had lower concentration of exchangeable magnesium than optimum range (soil nutrient distribution was unbalanced). It is suggested that farmers have to be careful to apply organic materials, especially containing livestock manure.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.211-219
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• 2023

Nutrient balance is an environmental indicator for assessing the potential of sustainable agriculture. Improving the use of arable land is crucial for reducing the nutrient balance. This study monitored soil water content, seepage water, crop growth, and nutrient balance in weighing lysimeters during forage barley (Hordeum vulgare L., "Yeongyang") cultivation from October to April. The study was conducted from 2020 to 2022, and the treatments included forage barley cultivation (clay loam, CL-FC; sandy loam, SL-FC) and bare soils. During the regeneration period (March to April), the soil moisture contents of bare and forage barley-cultivated soils were approximately 30-40% and 18.1-21.8%, respectively. The daily evapotranspiration of forage barley was 6.09 mm. The nitrogen balances for SL-FC and CL-FC were -0.43 to -2.93 g m^-2 and -0.79 to 0.75 g m^-2, respectively, which can be attributed to the higher nutrient uptake of forage barley in SL-FC than in CL-FC. Consequently, the forage barley cultivation in SL-FC can potentially reduce nutrient leaching during the spring rainy season. Furthermore, nutrient balance can be reduced by cultivating forage crops during the winter season.

• Digital Contents
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• no.12 s.151
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• pp.84-91
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• 2005

국내 온라인 게임시장은 화려한 그래픽과 사실성을 강조한3D 온라인게임과 아기자기한 그래픽을 보면서 부담없이 즐길수 있는 2D 캐주얼게임으로 양분된다. 이번에 소개하는 <큐링>은 이처럼 양분된 온라인 게임시장에서 틈새를 공략하고 있는3D 횡스크롤 캐주얼게임이다. 개그액션RPG로 잘 알려진‘ 씰온라인’의 개발사인 그리곤엔터테인먼트가 게임을 개발했고 파란에서 서비스하고 있다.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.471-475
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• 2007

This study was carried out to elucidate the relationship between yields and inorganic nutrient contents, and then establish of critical range of inorganic nutrient contents in leaves of net melon in protected cultivation in Naju from 2004 to 2006. In considering the yields and nutrient contents of net melon, the critical ranges of macro-nutrient contents in leaves of net melon at 25 days after transplanting were in N 3.4~4.8%, P 0.4~0.7%, K 3.4~5.1%, Ca 2.7~4.1% and Mg 0.6~0.8%, respectably. The critical ranges of micronutrient content, such as Fe, Mn, Zn, Cu and B, were not found the regular trend with different growth stages. However, the critical range of micronutrient contents in leaves of net melon at 25 days after transplanting were in Fe 102~164, Mn 52~116, Zn 28~98, Cu 7~15 and B $36{\sim}72mg\;kg^{-1}$, respectably. Finally, these results might be used at the indicator for critical nutrient contents for diagnosis of nutritional disorder in net melon in protected cultivation.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.51-58
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• 1990

The study was carried out to investigate the viability of mouse embryos bisected at the stages of 8-cell, morula and blastocyst and, also, to find out the feasibility of offspring production by transfer of the bisected blastocysts with Quick-splitting. The results obtained are summarized as follows: 1. The mouse embryos were bisected with bio-cut blade at the stages of 8-cell and morula, and cultured in Medium 2. The bisected embryos were developed to blastocyst stage by 64% and 81%. respectively. 2. The blastocyts which were cultured in Medium 2 after being bisected at the stages of 8-cell and morula were observed normal outgrowth in Ham's F-10 medium by 86% and 90%, respectively. 3. The blastocyts which were Quick-splitted in Medium 2 were observed normal outgrowth by 97%. however, no offspring was obtained by transfer of Quick-splitted blastocysts.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.213-236
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• 2001

The ionic composition of soil solution is related to a nutrient uptake by plant. Many models for estimating ionic composition of solution have been developed, and most of them have been used for calculating a content of mineral and ionic species in a geochemical point of view. An approximation model considering both cation and anion in soil solution was developed. Variables such as pH, Eh, EC, cations(K, Ca, Mg. Na, Fe, Mn, Al, $NH_4{^+}$), anions(Si, S, P, CY, $NO_3{^-}$, $HCO_3{^-}$ and chemical equilibria of ionic species in soil solution were input into Excel sheet. The activities of soluble ion, ionpairs and complexes of input element were estimated by Newton-Raphson method using conditional equilibrium constant calculated by Davies equation and special models. Equilibrium contents of insoluble minerals and complexes were also calculated.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.33-39
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• 2009

The practice of supplying nutrients for paddy soil with sustaining human health and ecological soundness is to utilize indicators considering soil chemical reactions. The long-term basis experiment of fertilizer and amendment of paddy soil and an experiment of yield response of soil types on nitrogen level from 2000 till 2002were used to search indicators of nutrient supplying capacity related to soil chemical reactions. Chemical reactions of paddy soil was composed of dissociating and/or adsorbing nutrients and of decomposing soil organic matter (SOM) into $H^+$, $e^-$, $CO_2$ in paddy soil. The indicators of nutrient supplying capacity, which were established by considering soil chemical reactions, were SOM or soil protein for nitrogen and available phosphate for phosphorus and cation exchangeable capacity (CEC) and exchangeable potassium for potassium. Korea has used fertilizer recommendation equations established with the indicators of nutrient supplying capacity for paddy soil.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.173-179
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• 2017

Advanced countries, animal wastes are produced using bioenergy and methane gas technology. In Korea, many researches are being actively carried out to develop livestock manure as a resource technology rather than a animal waste. However, the production of bio-gas using livestock manure is still in the process of development of functional livestock and compost because of low economic efficiency with livestock manure recycling technology. In this paper, in order to accurately estimate the manure output, It will calculate the manure excretion if you have finished input the number of pigs. In addition, we simulated the fertilization rate of three elements of NPK fertilizer per 100 square meters automatically.

• Environmental and Resource Economics Review
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• v.20 no.1
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• pp.119-153
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• 2011

This study reviews various aspects of model formulating processes of dichotomous choice responses of the contingent valuation method (CVM), which has been increasingly used in the preliminary feasibility test of Korea public investment projects. The theoretical review emphasizes the consistency between WTP estimation process and WTP measurement process. The empirical analysis suggests that two common parametric models for dichotmous choice responses (RUM and RWTP) and two commonly used probability distributions of random components (probit and logit) resulted in all most the same empirical WTP distributions, as long as the WTP functions are specified to be a linear function of the bid amounts. However, the efficiency gain of DB response compared to SB response were supported on the ground that the two CV responses are derived from the same WTP distribution. Moreover for the exponential WTP function which guarantees the non-negative WTP measures, sample mean WTP were quite different from median WTP if the scale parameter of WTP function turned out to be large.