• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.554-567
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• 2019

Recently, concerns regarding the environmental impact due to nutrient input in croplands have increased. Therefore, the government is promoting the introduction of a nutrient management system in croplands to solve the problem of excessive nutrient input. This study was carried out to establish nutrient indicators in regional croplands to facilitate the introduction of the national nutrient management system in Korea. The nutrient load and balance indicators for nitrogen and phosphorus were analyzed for nine provinces (Gang-won, Gyeong-gi, Chung-buk, Chung-nam, Jeon-buk, Jeon-nam, Gyeong-buk, Gyeong-nam, and Jeju). In the correlation analysis between the nutrient load and nutrient balance, the correlation coefficient (r) for nitrogen was 0.2504, which was not statistically significant at the 5% significance level. However, the correlation coefficient for phosphorus was 0.7375, which was statistically significant at the 5% significance level. In the nutrient management index, phosphorus showed mutual compatibility between the nutrient load and the nutrient balance indicators, but nitrogen showed no mutual compatibility between the nutrient load and the nutrient balance indicators. Therefore, utilization of the nutrient balance indicator, reflecting the characteristics of the agricultural environment, was more reasonable as a nutrient management index for regional nutrient management.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.05a
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• pp.5-10
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• 1997

본 실험은 온실멜론을 암면재배하여 수분전후 21일간 질소공급제한이 생육, 품질 및 양분흡수에 미치는 영향을 조사하였다 가을과 겨울재배에서는 상당히 고농도의 양분을 흡수하는 시기이기 때문에 시즈오카대 처방(NO$_3$-N = 8me/$\ell$)을 이용하여 재배하고 양분도 제한했기 때문에 식물체는 양분부족 현상을 야기하였다. 교배 후 양분흡수를 제한하는 경우 상위엽의 과잉비대를 방지하였으나 초장과 과실의 생체증은 양분공급을 제한하지 않는 경우에 크게 나타났다. 그 원인은 양분공급을 제한하는 기간 및 시기와 시용배양액 농도 차이에 따른 양분흡수량의 차이라고 생각되었다. 이상으로부터 수분기에는 양분흡수량이 많기 때문에 양분공급을 제한하지 않고 양분공급을 증가시키는 편이 과실의 외관, 품질향상 및 과실의 당도향상에 상당히 기여할 것으로 생각되었다.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.656-666
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• 1996

Aspen demand has increased recently in the Great Lakes region in the United States. Since aspen has moved into the region in late 1800's, its growing stock has increased so as to change forestry industry of the Lake States. Intensive timber harvesting and biomass removal may cause nutrient depletion, especially on nutrient-poor sites. Forest nutrients and nutrient cycling were investigated in aspen stands of 7-10, 27-33, and 41-42 year-old growing on sandy soils in Minnesota. Nutrients added to the aspen stands by atmospheric deposition and soil weathering were efficiently absorbed and stored in the tree biomass. Aboveground biomass increased from $24.4t{\cdot}ha^{-1}$ at young stands to $139.2t{\cdot}ha^{-1}$ at mature stands. Nutrients accumulated in the tree biomass showed same magnitude of difference. Nutrients added to the site through atmospheric deposition were in the order of Ca, N, K, Mg, and P. Annual litterfall was greater in older stands. However, the amount of nutrients returned by litterfall was not significantly different among stand ages due to the greater nutrient contents in the litterfall of young stands. Litter decomposition and nutrient release rates were greater at young stands than at older stands. Likewise, nutrient availability was higher in young aspen stands and became lower as the stands grew older. Nutrient leaching loss was minimal at all stand ages. Soil N mineralization was greater at young stands than at older stands. Nutrient cycling process was facilitated in young aspen stands with an increased level of available nutrients, Based on the estimations of nutrient balance and nutrient removal by harvesting, Ca was the most critical element which was likely to be depleted if aspen stands are intensively harvested with short rotations.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.328-335
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• 2023

For appropriate nutrient management and enhanced plant growth, soil sensors which reflect soil nutrient levels are required. Because there is no available sensor for nutrient monitoring, electrical conductivity (EC) sensor can be used to evaluate soil nutrient levels. Soil nutrient management using EC sensors would be possible by understanding the relationship between sensor EC values and soil temperature, moisture, and nutrient content. However, the relationship between soil sensor EC values and plant available nutrients was not investigated. Therefore, the objectives of the study were to evaluate effect of different amount of urea on soil EC monitored by sensors during pepper and broccoli cultivation and to predict the plant available nutrient contents in soil. During the cultivation period, soil was collected periodically for analyzing pH and EC, and the available nutrient contents. The sensor EC value increased as the moisture content increased, and low fertilizer treated soil showed the lowest EC value. Principal component analysis was performed to determine the relationship between sensor EC and available nutrients in soil. Sensor EC showed a strong positive correlation with nitrate nitrogen and available Ca. In addition, sum of available nutrients such as Ca, Mg, K, P, S and N was positively related to the sensor EC values. Therefore, EC sensors in open field can be used to predict plant available nutrient levels for proper management of the soil.

• The Korean Journal of Ecology
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• v.27 no.4
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• pp.199-210
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• 2004

Effects of nitrogen and phosphorus fertilization on seasonal changes of nutrient content in tree components, and retranslocation N and P in foliage and twig were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeonggi Province. In general, foliage N and P concentrations of L kaempferi were significantly higher than current and 1-year-old foliages of P. rigida. N and P concentrations were higher in foliage than in twigs for both tree species. However, there were no significant differences in foliage and twig N and P concentrations with ages. Significant seasonal differences in foliage and twig N and P concentrations were observed for both tree species because of nutrient retranslocation. Foliage nutrient concentrations were highest in the mid-growing season and lowest in autumn, whereas twig nutrient concnetrations have gradually increased since July. These seasonal trends indicated nutrient retranslocation from foliage into twigs before foliage senescence. However, there were no significant changes in foliage and twig nutrient retranslocation, and no consistent patterns in foliage and twig nutrient retranslocation following N and P fertilizer additions. No significant changes in nutrient retranslocation between different foliage and twig ages were observed following fertilization.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.25-30
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• 1984

Rice seedlings were raised in seedling box for rice transplanter at the temperatures of 32$^{\circ}C$ (day/1$0^{\circ}C$(night) and $25^{\circ}C$/1$0^{\circ}C$ in a phytotron. The endosperm materials were consumed more rapidly at the high temperature (32/1$0^{\circ}C$) than at the low temperature (25/1$0^{\circ}C$) and thus the leaf development was proloted at the high temperature for 15 days from the sowing. But at 35 days after sowing more leaves were developed at the low temperature than the high temperature. The short cotyledon length(5mm) before sowing was more available for the leaf development than the long cotyledon(20mm) because the endosperm materials of the former were consumed slowly. The residual of 10% endsoperm materials, when seedling age was of 2.0 to 2.1, promoted the regrowth of seedlings after machine transplanting.

• Environmental and Resource Economics Review
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• v.8 no.1
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• pp.51-73
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• 1998

조건부가치측정법(CVM)의 지불의사 유도방법인 이중 양분선택형 질문법은 단일 양분선택형 질문 CV자료의 통계적 비효율성을 극복하기 위한 방법으로 제안되었다. 이 방법은 여러 가지 장점에도 불구하고 출발점 편의의 심리학적 근거인 정박효과 (anchoring effect)의 발생 가능성을 의심받고 있다. 그러므로 본 논문에서는 이중 양분선택형 질문 CV자료에서 정박효과를 검토할 수 있는 일반적 지불의사금액모형을 제시하고, 그 모형으로부터 정박효과를 검토할 수 있는 방법을 제안한다. 모형은, Cameron and Quiggin(1994)이 제안한 이변량 모형에 두 번째 내재 지불의사금액의 설명변수로서 처음 제시된 특정금액에 대한 양분선택적 응답결과를 포함시킨 형태이다. 이 모형에서 처음 제시된 특정금액에 대한 양분선택적 응답결과의 계수 부호가 음(-)이고 통계적으로 유의하다면 정박효과가 발생하는 것으로 볼 수 있다. 그러나 만약 이러한 계수 검토에서 정박효과 발생을 확인할 수 없는 경우, 두 번의 응답에서 두 지불의사금액 추정치들의 평균이 다르다고 볼 수 없다면 정박효과를 우려할 필요가 없다. 이 검토 모형 및 방법을 본 연구에서 한강 수질 개선에 대한 CV자료에 적용해 본 결과 정박효과를 우려할 필요가 없음을 확인할 수 있다.

• 농업기술회보
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• v.51 no.4
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• pp.24-25
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• 2014

모든 작물의 생육에는 양분관리가 필수적으로 유기농에서도 중요하기는 마찬가지이다. 유기농업에서 양분관리는 녹비와 퇴비를 공급하는 것을 기본으로 하며 양분이 부족한 경우 다양한 유기물을 이용하여 농가에서 액비를 자가 제조하여 사용하고 있다.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.85-95
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• 2010

The purpose of this study was to quantitatively measure both growth performances and nutrient responses of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla seedlings, which are commercially planted in Korea, to nitrogen, phosphorus, and potassium fertilization. We used Dickson's quality index (QI) to compare growth performances and vector diagnosis to interpret nutrient status. Nitrogen fertilization increased more height and root collar diameter growth in F. rhynchophylla and F. mandshurica relative to no fertilization treatment. The QI of F. rhynchophylla and F. mandshurica was the highest on N treatment, but there were no significant differences between treatments for P. koraiensis and A. holophylla. Nitrogen fertilization increased total dry weight by 43, 41, 26, -9% for F. rhynchophylla, F. mandshurica, P. koraiensis and A. holophylla, respectively. In F. rhynchophylla, N fertilization increased N contents with similar N concentrations ("sufficiency"), decreased both P concentrations and P contents ("antagonism"), and decreased K contents with similar K concentrations ("toxic accumulation"). In P. koraiensis, N fertilization decreased N, P, and K concentrations because of more dry weight increases compared to uptaken contents ("dilution"), but N fertilization decreased N, P, and K contents with similar N, P, and K concentrations ("toxic accumulation"). In the light of quality index and vector diagnosis, F. rhynchophylla and F. mandshurica seedlings treated with N fertilization would have high field performance.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.388-396
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• 2017

This study was carried out to determine effects of bamboo species on the distribution of nutrients in aboveground biomass of Phyllostachys bambusoides and Phyllostachys nigra var. nenosis, Damyanggun, Korea. The study site was established around 40-year-ago to produce bamboo culm and edible shoot production. Total 28 bamboos (14 P. bambusoides and 14 P. nigra var. nenosis) were cut to measure nutrient concentration of each bamboo component, such as culm, branches and leaf. Magnesium concentration in each bamboo component was significantly higher in the P. bambusoides than in the P. nigra var. nenosis. Nutrient concentrations except for calcium were significantly higher in the current-year-old bamboos than in the > 1-year-old bamboos. The nutrient concentration in leaf was generally highest in carbon, followed by potassium or nitrogen, phosphorus, calcium or magnesium. Total nutrient content in each bamboo component was significantly higher in the P. bambusoides than in the P. nigra var. nenosis. The nutrient content of bamboo biomass was the highest in carbon, followed by potassium, nitrogen, phosphorus, magnesium and calcium. The results indicate that P. bambusoides uptakes more nutrients compared with P. nigra var. nenosis during growth development.