• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.1-15
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• 2004

Due to recent scientific innovations in mulberry cultivation, leaf yield has been increased manifold. However, with successive leaf harvest, a quantum drop in leaf yield and quality has been noted. This inturn has affected the silkworm rearing and farmers suffered by the frequent crop failures. This is mainly due to nutrient deficiencies in mulberry leaf. Moreover, no complete information is available about hunger signs of nutritional disorders, analytical diagnosis and critical levels of nutrients required. The present paper, thus, may serve as an important nutrient guide for identification of hunger signs, leaf nutrients status under deficiency and critical levels of the elements namely N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn requirements for higher leaf yield and quality. The leaf nutrient status provided may help chemist for correcting the soil status. Besides, an integration of mulberry intercropping with legumes and applications of neem and castor oil cakes, VA-mycorrhizal inoculation, biofertilizer and vermicompost are suggested as integrated nutrient management for sustainable sericulture industry. Based on the information described in this paper, a model needs to be framed for maintaining continuous supply of nutrients to obtain desired quantity and quality of mulberry leaf for successful silkworm cocoon crop and increasing overall silk productivity.

• The Korean Journal of Ecology
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• 제21권4호
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• pp.329-335
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• 1998

The growth of Phytolacca L. grown under three light regimes at three nutrient concentrations was analyzed. The effect of shading treatment on plnat growth was greater than that of nutrient treatment. Plant dry mass increased more than 5-fold during 21 days under 33% and 100% irradiances, whereas that was strongly reduced under 8% irradiance. Net assimilation rate decreased with plant growth irrespective of light and nutrient treatments, though the highest net assimilation rate was shown under 100% irradiance. Under 33% irradiance leaf area in plants supplied with nutrient solution increased to such extent as to compensate reduction in net assimilation rate, whic maintains almost identical growth rate with that under 100% irradiance. The relatonship between total plant nitrogen and leaf nitrogen content was dependent on the growth irradiance. Moreover, leaf nitrogen and specific leaf weight were also changed depending on the light and nutrient conditions. Based on these findings, it is suggested that the adaptive characteristics of Pokeberry plant to light and nutrient conditions may contribute to rapid extension of Pokeberry habital in Korea rocently.

• 한국농림기상학회지
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• 제7권3호
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• pp.192-200
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• 2005

본 연구는 배 신고 품종의 영양 진단을 위해 과총 잎과 신초 잎을 구별한 무기성분 변화와 기상요인이 잎의 무기성분 함량에 미치는 영향을 조사하였다 과총 잎의 N, P, K, Mg 함량은 후기로 갈수록 감소되었으나, Ca, Mn 함량은 증가되었다. N, P, K, Fe 함량은 과총 잎과 신초 잎의 함량 차이가 거의 없었다. 과총 잎의 Ca, Mn, Cu, Zn성분은 신초 잎보다 높았으나, B 성분은 신초 잎보다 낮았다. 신초 잎의 N 성분은 평균 기온과는 정의 상관이, 최고 기온과는 부의 상관이 인정되었다. 과총 잎의 P 성분과 최고 기온과는 부의 상관이 인정되었다. 과총 잎의 Ca 성분은 평균 기온과는 부의 상관이, 최고, 최저 기온과는 정의 상관을 보였다. 신초, 과총 잎의 Mg, B 성분과 평균 기온과는 정의 상관이, 최고, 최저 기온과는 부의 상관이 인정되었다. 일반적인 잎 채취 시기인 7월 중순${\~}$8월 상순 사이의 과총 잎 내 Ca, Mn 함량은 신초 잎보다 확연히 높았기 때문에 정확한 영양진단을 위해서는 신초 잎과 과총 잎을 구별하여 채취하는 것이 좋을 것으로 판단된다.

• Journal of Forest and Environmental Science
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• 제29권1호
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• pp.38-48
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• 2013

Decomposition of plant material is an important component in the study of forest ecosystem because of its critical role in nutrient cycling. Different tree species has different nutrient release patterns, which are related to leaf litter quantitative traits and seasonal environmental factors. The quantitative traits of leaf litter are important predictors of decomposition and decomposition rates increase with greater nutrient availability in the forest ecosystems. At the ecosystem level, litter quantitative traits are most often related to the physical and chemical characteristics of the litter, for example, leaf toughness and leaf mass per unit area, and lignin content tannin and total phenolics. Thus, the analysis of litter quantitative traits and decomposition are highly important for the understanding of nutrient cycling in forest ecosystems. By studying the role of litter quantitative traits on decomposition and nutrient cycling in forest ecosystems will provide a valuable insight to how quantitative traits influence ecosystem nutrient dynamics. Such knowledge will contribute to future forest management and conservation practices.

• The Korean Journal of Ecology
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• 제26권6호
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• pp.313-319
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• 2003

Dry weight loss and nutrient release from leaf litter for six tree species were studied using litter bag methods. The litter bags were incubated for f6 months on the forest floor in temperate deciduous forest in Mt. Cheonma, located at the middle part of Korean Peninsula. The changes in nutrient content and the rate of dry weight loss in leaf litter varied with litter types. The litter of Pinus densiflora showed the lowest rate of mass loss (k=0.33), nitrogen concentration (0.89%) and ash concentration (2.50%), while showed the highest C/N ratio (63.40). On the other hand, the litter of Acer pseudo-sieboldianum showed the fastest rate of mass loss (k=0.82), the highest nitrogen concentration (1.11%), and the lowest C/N ratio (49.40). During the decomposition, nitrogen, phosphorus and calcium in the leaf litters showed relatively slow decreasing pattern compared to other elements (carbon, potassium, magnesium, manganese and sodium), but potassium and sodium decreased at early stage of the decomposition for all leaf litters. Differences in annual decomposition rates of litter among species were consistent with the particular chemical characteristics of their leaf litters. The initial concentration of nitrogen was positively correlated with litter decomposition rate for six species, while litter decomposition rate of six species was negatively correlated with C:N ratio of initial leaf litters.

• Animal cells and systems
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• 제7권4호
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• pp.289-294
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• 2003

To quantify nutrient loading from emergent macrophytes through leaching in the littoral zones of Paldang Reservoir, we conducted incubation experiments using leaf litter of the emergent macrophyte, Zizaniz latifolia. To separate the leaching process from microbial decay, we used $HgCl_2$ to suppress microbial activity during the experiment. We measured electric conductivity, absorbance at 280nm, total nitrogen and dissolved inorganic nitrogen, total phosphorus and soluble reactive phosphorus, Na, K, Mg and Ca amounts in leaf litter and in water. In addition, we examined the effects of water temperature and ion concentrations of ambient water on the leaching process. A total of 6% of the initial ash-free dry mass of leaf litter was lost due to leaching during incubation (four days). Electric conductivity and A280 continued to increase and saturate during the incubation. To compare reaching rates of different nutrients, we fitted leaching dynamics with a hyperbolic saturation function [Y=AㆍX/(B+X)]. From these fittings, we found that ratios of leaching amounts to nutrient concentration in the litter were in the order of K > Na > Mg > P > Ca > N. Leaching from leaf litter of Z. latifolia was dependent on water temperature while it was not related with ion concentrations in the ambient water. Our results suggest that the leaching process of nutrients, especially phosphorus, from aquatic macrophytes provides considerable contribution to the eutrophication of the Paldang Reservoir ecosystem.

• 현장농수산연구지
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• 제19권1호
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• pp.5-14
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• 2017

본 연구는 인공광을 이용한 순환식 수경재배시 배양액농도가 적축면 상추 생육과 배양액내 다량 원소 농도의 변화에 미치는 영향을 구명하고자 수행되었다. 형광등과 LED의 광도는 100μmol m^-2·s^-1±20 수준이었으며, 배양액 농도는 일본 야채다업시험장 표준배양액의 1/2배액, 1배액 및 2배액 수준이었다. 일주일마다 줄어든 배양액 양만큼 보충하면서 재배되는 수경재배시스템에서 적축면 상추('뚝섬' 동부하이텍, 품종)를 재배하였다. 적축면 상추의 생육은 농도가 진한 2배액에서 가장 좋은 것으로 나타났다. 재배기간 중 배양액의 EC는 1배액에서는 2dS.m^-1 내외에서 비교적 안정적으로 유지된 반면 2배액에서는 상승하는 경향을 보였다. 배양액의 무기성분 함량은 2배액, 1배액, 1/2배액 순으로 높았다. 재배기간 중 배양액 내 NO₃-N, Ca²⁺, Mg²⁺ 농도는 1배액, 2배액에서 지속적으로 증가한 반면, NH₄-N 농도는 1배액, 1/2배액에서 지속적으로 감소하는 결과를 나타내었다. 적축면 상추 엽내 K, Ca, Mg 함량은 정상 범위를 유지한 반면, P 함량은 1.3~1.6%로 적정 성분함량 범위 보다 높게 나타났다. 적축면 상추재배 시 재배기간이 경과함에 따라 NH₄-N 함량이 감소하는 경향을 보여 NH₄-N 비율을 높이거나 더 첨가해 줄 필요가 있는 것으로 나타났다.

• 한국약용작물학회지
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• 제21권4호
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• pp.289-295
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• 2013

This study was carried out to investigate the cause of leaf discoloration occurring frequently in paddy cultivation. Chemical property of soil and inorganic nutrient component of leaf were analyzed on abnormal fields of 7 regions where leaf discoloration occurred severely and normal fields of 7 regions among ginseng garden. The pH of abnormal fields was strong acidic condition (pH 5.51) compare to normal fields of slightly acid condition (pH 6.42). Calcium and magnesium content in abnormal fields were lower distinctly than that of normal fields, while EC, organic matter, phosphate, and potassium content showed not distinct difference between abnormal and normal fields. Whereas calcium and magnesium content were distinctly high in normal fields, both of potassium and iron content of ginseng leaf were distinctly high in abnormal fields. In particular, iron content of abnormal fields was more 1.94 times in soil, and 3.03 times in leaf than that of normal fields. In soil chemical property, there were significant negative correlation between leaf discoloration ratio and soil pH, and there were also significant positive correlation between leaf discoloration ratio and iron content. In ginseng leaf, there were highly significant negative correlation between leaf discoloration ratio and calcium content, and there were also highly significant positive correlation between leaf discoloration ratio and iron content.

• 생물환경조절학회지
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• 제24권4호
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• pp.271-274
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• 2015

식물공장에서 양액 종류가 다채, 로메인, 비트, 적무 어린잎채소의 생육 및 품질에 미치는 영향을 알아보기 위해서 본 연구를 수행하였다. 우레탄스펀지에 파종한 후 14일간 광원을 형광등으로 하는 폐쇄형 재배 시스템에서 재배하였다. 재배 시스템 내 광도는 $110{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 명암주기는 16/8h, 명/암기 기온은 $25/20^{\circ}C$로 유지하였다. 파종 후 7일은 수돗물을, 이후 7일은 수돗물, 한국 원시, 일본 엔시, 상추용 야마자키 양액을 각각 관수하였다. 파종 14일 후 다채의 생체중은 야마자키 양액을 공급한 처리구에서 가장 높았으나, 비트와 적무의 생체중은 양액 종류 간 유의차가 없었다. 소비자들의 구매 결정 주요 요인 중 하나인 엽색을 비교하기 위하여 양액 종류에 따른 4작물의 Hunter's L과 a값을 측정하였다. 어린잎채소의 녹색과 적색을 Hunter's a값으로 비교하였을 때, 한국 원시와 일본 엔시 양액을 공급한 처리구에서는 녹색을, 야마자키 양액을 공급한 처리구에서는 적색을 더 띄었다. 다채, 비트, 적무의 총페놀함량은 양액 종류에 따른 차이가 없었으나, 로메인은 한국 원시 양액을 공급한 처리구에서 총페놀함량이 가장 높았다. 이상의 결과에서 어린잎채소의 생육과 품질을 고려해 볼 때, 식물공장 재배 시 로메인은 한국 원시 양액이, 비트와 적무는 야마자키 양액이 적합한 것으로 판단된다.

• The Korean Journal of Ecology
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• 제7권3호
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• pp.170-176
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• 1983

The results obtained from the experiments conducted to investigate Cruciferae plants in rape dependent on the amount of applied fertilizer in aspects of mineral nutrient uptake and on the effects of the composition of oil quality are as follows: Absorption of mineral nutrients in the respective pars of the plant body was high in nitorgen in the order of leaf and stem