• Journal of Ginseng Research
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• 제41권2호
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• pp.195-200
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• 2017

Background: The natural ratios of carbon (C), nitrogen (N), and sulfur (S) stable isotopes can be varied in some specific living organisms owing to various isotopic fractionation processes in nature. Therefore, the analysis of C, N, and S stable isotope ratios in ginseng can provide a feasible method for determining ginseng authenticity depending on the cultivation land and type of fertilizer. Methods: C, N, and S stable isotope composition in 6-yr-old ginseng roots (Jagyeongjong variety) was measured by isotope ratio mass spectrometry. Results: The type of cultivation land and organic fertilizers affected the C, N, and S stable isotope ratio in ginseng (p < 0.05). The ${\delta}^{15}N_{AIR}$ and ${\delta}^{34}S_{VCDT}$ values in ginseng roots more significantly discriminated the cultivation land and type of organic fertilizers in ginseng cultivation than the ${\delta}^{13}C_{VPDB}$ value. The combination of ${\delta}^{13}C_{VPDB}$, ${\delta}^{15}N_{AIR}$, or ${\delta}^{34}S_{VCDT}$ in ginseng, except the combination ${\delta}^{13}C_{VPDB}-^{34}S_{VCDT}$, showed a better discrimination depending on soil type or fertilizer type. Conclusion: This case study provides preliminary results about the variation of C, N, and S isotope composition in ginseng according to the cultivation soil type and organic fertilizer type. Hence, our findings are potentially applicable to evaluate ginseng authenticity depending on cultivation conditions.

• Asian-Australasian Journal of Animal Sciences
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• 제24권3호
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• pp.358-363
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• 2011

To investigate the effect of nitrogen fertilization on the quality of tropical grass silage, guinea grass grown with 3 types of nitrogen fertilizers, namely, urea, ammonium sulfate, and compound fertilizer 804, at 2 fertilization levels, 0.5 and 2.5 kg $Na^{-1}$ (0.5 N and 2.5 N, respectively), was subjected to silage fermentation. Silage fertilized with 0.5 N showed butyrate-dominant fermentation, irrespective of the type of fertilizer used. On the other hand, fermentation of silage fertilized with 2.5 N was significantly affected by the type of fertilizer used; fertilization with ammonium sulfate and compound fertilizer 804 resulted in silage that contained a large amount of butyrate and no lactate; this silage was considered to be of a significantly low quality as compared with silage fertilized with 0.5 N. Among silage fertilized with 2.5 N, the desirable butyrate-free fermentation was found only in urea-fertilized silage, which had the best quality. Grass material fertilized with a high level of urea accumulated a relatively high concentration of nitrate nitrogen (0.22% dry matter). Our results presented here suggest that nitrogen fertilizer management could affect the quality of tropical grass silage and that a relatively high concentration of nitrate in silage may promote butyrate-free fermentation even in tropical grass silage.

• 한국환경농학회지
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• 제39권4호
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• pp.297-304
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• 2020

BACKGROUND: Emission of nitrous oxide (N2O) from the soil is expected to depend on the types of nitrogen fertilizer used. Biochar has recently been proposed as a potential mitigation of climate change by reducing the N2O emission. Although laboratory studies reported that biochar applications could reduce N2O emission, the number of field-based studies is still limited. Therefore, a field experiment was conducted to investigate the effect of biochar on N2O emission when different nitrogen fertilizers were applied in corn cultivated field. METHODS AND RESULTS: The field experiment consisted of six treatments: urea fertilizer without biochar (U), ammonium sulfate fertilizer without biochar (A), oil cake fertilizer without biochar (O), urea fertilizer with biochar (U+B), ammonium sulfate fertilizer with biochar (A+B), and oil cake fertilizer with biochar (O+B). Biochar was applied at a rate of 10 t/ha. Greenhouse gas fluxes were measured during growing seasons using static vented chambers. The cumulative N2O emissions were 0.99 kg/ha in the U, 1.23 kg/ha in the A, 3.25 kg/ha in the O, 1.19 kg/ha in the U+B, 0.86 kg/ha in the A+B, and 1.55 kg/ha in the O+B. CONCLUSION: It was found that N2O emission was related to application of both nitrogen fertilizer type and biochar. In particular, the N2O reduction effect was the highest in the corn field incorporated with biochar when oil cake was applied to the soil.

• 한국토양비료학회지
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• 제50권6호
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• pp.530-537
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• 2017

Composted animal manure added for improving soil quality and enhancing crop productivity can lead to greenhouse gas emissions such as nitrous oxide ($N_2O$) by processes of nitrification and denitrification. In addition, the amount of $N_2O$ emission from composted manure amended soils can vary greatly with composted manure type or different soil type. Therefore, the influence of cattle composted manure on $N_2O$ emissions was evaluated during growth of sweet potato (Ipomoea batatas). The treatments included control, conventional fertilization (CF), and CF + cattle composted manure (CCM) $10Mg\;ha^{-1}$ were applied in the spring. $N_2O$ emissions were significantly affected by composted manure and chemical fertilizer and the CCM had greater N2O emissions compared with other treatments. The majority of $N_2O$ emissions occurred shortly after composted manure and chemical fertilizer application compared with the rest of the growing seasons for all treatments. Also, $N_2O$ flux was associated with water-filled pore space (WFPS) at all treatments. On average of $N_2O$ emission accumulation, the CCM was 1.5 times greater than control treatment while there was no difference between CF and control.

• Journal of Biosystems Engineering
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• 제27권3호
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• pp.259-266
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• 2002

It is crucial to know spatial soil variability for precision farming. However, it is time-consuming, and difficult to measure spatial soil properties. Therefore, there are needs fur sensing technology to estimate spatial soil variability, and for electronic mapping technology to store, manipulate and process the sampled data. This research was conducted to develop a real-time soil organic matter sensor and an electronic mapping system. A soil organic matter sensor was developed with a spectrophotometer in the 900∼1,700 nm range. It was designed in a penetrator type to measure reflectance of soil at 15cm depth. The signal was calibrated with organic matter content (OMC) of the soil which was sampled in the field. The OMC was measured by the Walkeley-Black method. The soil OMCs were ranged from 0.07 to 7.96%. Statistical partial least square and principle component regression analyses were used as calibration methods. Coefficient of determination, standard error prediction and bias were 0.85 0.72 and -0.13, respectively. The electronic mapping system was consisted of the soil OMC sensor, a DGPS, a database and a makeshift vehicle. An algorithm was developed to acquire data on sampling position and its OMC and to store the data in the database. Fifty samples in fields were taken to make an N-fertilizer dosage map. Mean absolute error of these data was 0.59. The Kring method was used to interpolate data between sampling nodes. The interpolated data was used to make a soil OMC map. Also an N-fertilizer dosage map was drawn using the soil OMC map. The N-fertilizer dosage was determined by the fertilizing equation recommended by National Institute of Agricultural Science and Technology in Korea. Use of the N-fertilizer dosage map would increase precision fertilization up to 91% compared with conventional fertilization. Therefore, the developed electronic mapping system was feasible to not only precision determination of N-fertilizer dosage, but also reduction of environmental pollution.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권6호
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• pp.26-32
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• 2019

An analysis of groundwater quality is significant for monitoring and managing water contamination and groundwater system. For the purpose of those, the geochemical characteristics of groundwater were studied over the concern for water quality, water type and origin of nitrate nitrogen. Total colony counts were detected in 11 out of 20 samples, and the average value was 31.73 CFU/ml. Range and average of NO₃-N concentrations were 0.9~24.0 mg/L and 8.3 mg/L. All groundwater types were found to be Ca²⁺-HCO₃^-. The range and average of NO₃-N were 0.2~17.4 mg/L and 8.7 mg/L, and those of δ¹⁵N were 1.7~8.9‰, and 5.0‰. Careful consideration is required for evaluating the origin of nitrogen when NO₃-N concentration is low. In general, noticeable difference between rockbed and alluvial water was not found. The ranges of nitrate origins by chemical fertilizer, livestock manure and domestic sewage, and natural soil were 29.6~76.4%, 14.2~58.9% and 2.6~7.0%, and the average values of those were 57.4%, 37.4%, and 5.3%, respectively. Origin of nitrate was affected by more chemical fertilizer than the other parameters. Rockbed water was more affected by chemical fertilizer than alluvial water.

• 한국토양비료학회지
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• 제49권6호
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• pp.689-698
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• 2016

Specific metabolic network responses to mineral starvation are not well-defined. We examined a detailed broad-scale identification of metabolic responses of tomato leaf and root to N, P or K starvation. Tomato plants were grown hydroponically under optimal (5 mM N, 0.5 mM P, or 5 mM K) and starved (0.5 mM N, 0.05 mM P, or 0.5 mM K) conditions and metabolites were measured by LC-MS and GC-MS. Overall, the levels of metabolites (lipids, nucleotides, peptides and secondary metabolites) presented in this paper largely showed mineral- and tissue-specific responses. Most strikingly, G3P (glycerol-3-P), GPC (glycerol-P-choline) and choline phosphate responded differently to a type of mineral; an increase in N or K starvation and a decrease in P starvation. A dramatic increase in the levels of secondary metabolites, in particular, rutin and chlorogenate in both tomato tissues during N starvation were observed. Based on these data, it is necessary to clearly elucidate an unknown event taking place in a variety of abiotic impacts, and we are now studying to expand our knowledge on metabolic- and proteomic-responses using GS-MS and LC-MS.

• 농업과학연구
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• 제49권4호
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• pp.709-718
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• 2022

Nitrogen (N) is a vital element in growing crops and is essential for improving the yield and quality of crops. Thus, N fertilizer is the most widely used fertilizer and the primary N input source in soil-crop systems. Inorganic fertilizers such as urea are known to improve crop productivity and increase soil fertility. However, application with excessive amounts can interfere with crop growth and accelerate soil acidification. For these reasons, the use of organic fertilizers, which mainly contain organic nitrogen, has gradually increased worldwide. Therefore, this study evaluated the effects of N fertilizer on the growth of Chinese cabbage including its functional compounds glucosinolates (GSLs). For the cultivation of Chinse cabbage, inorganic fertilizer was used for urea, and organic fertilizers were divided into conventional and biochar-based fertilizers. The growth parameters of Chinese cabbage treated by organic fertilizers was better than those of the inorganic fertilizers. Additionally, it was found that their co-application was more efficient. However, their GSL contents were lower with the application of the organic fertilizers. The characteristics of the experimental soil also changed according to the type, amounts and co-application of fertilizers. Therefore, this study presents the basis for an eco-friendly method that can increase the functionality and productivity of Chinese cabbage compared to conventional cultivations.

• 한국토양비료학회지
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• 제44권3호
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• pp.344-346
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• 2011

산중식 경도 (YA, MPa)와 관입식 경도 Cone index (PE, MPa) 의 측정치를 토양특성이 다른 16개 지점에서 비교해 본 결과, 다음과 같은 회귀식을 구할 수 있었다. $$PE=YA^*1.80+0.16(R^2=0.91^{***},N=16)$$ 이 회귀식의 적용범위는 산중식경도 0.1 MPa 이상 1.3 MPa 이하, mm 단위로 8.0 mm 이상 24.5 mm 이하였다.

• 한국초지조사료학회지
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• 제5권2호
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• pp.136-142
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• 1985

임목(林木)과 초사료생산(草飼料生産)이라는 측면에서 임간초지개발(林間草地開發)은 우리 나라에서 중요한 과제라 할 수 있다. 본(本) 시험(試驗)은 임간혼파초지(林間混播草地)에서 생산성향상(生産性向上)과 이용기간연장(利用期間延長)을 위한 적정시비수준(適正施肥水準)을 구명(究明)하고자 수령((樹齡) $10{\sim}15$년간(年間) 소나무지대(차광정도(遮光程度) $40{\sim}50%$)에서 질소, 인산, 칼리비료의 수준을 달리한 13가지 시비수준(施肥水準)을 난괴법으로 배치하여 목초의 생육특성, 엽록소함량, 재생과 건물수량 등을 조사하였다. 1984년(年) 수원 근교 임간지에서 수행된 시험(試驗)의 결과(結果)를 요약(要約)하면 다음과 같다. 1. 초고(草高)와 목초피복율(牧草被覆率)은 대체로 표준비 이상의 질소시비구에서 높았으며, 3 요소 무비구와 질소무비구에서 가장 부족(不足)하였고, 최종예취후 나지율(裸地率) 질소수준이 낮을 때 높았다. 2 엽신(葉身)의 엽록색도(葉綠色度)와 엽록소함량(葉綠素含量)은 질소수준이 표준비 이상인 구에서 높았으며 3요소 무비구와 질소무비구에서 가장 낮았다. 엽부패도(葉腐敗度)와 초형(草型)은 질소수준이 높을 때 불량(不良)해지는 경향을 보였다. 3 1차(次) 예취후(刈取後) 목초(牧草)의 시기별(時期別) 재생력(再生力)은 표준비이상의 질소시용구에서 양호(良好)하였으며, 3요소무비구와 질소무비구는 재생초장(再生草長)과 재생건물중(再生乾物重) 증가속도가 가장 불량(不良)하였다.4. 목초(牧草)의 건물수량(乾物收量)은 질소수준이 표준비 이상인 구에서 많았으며 3 요소무비구와 질소무비구에서 가장 적었다(P<0.05). 본 시험에서 표준비구, 3요소 50% 증비구 및 질소 50% 증비구에서 높은 수량(收量)을 기대할 수 있었으며 세 처리간 유의차는 없었다. 5 목초(牧草)의 생육(生育), 재생(再生) 및 수량(收量)은 3요소 비료중 질소시용에 의해 가장 큰 영향을 받았으며 인산과 칼리비료의 영향은 작았다. 본(本) 시험(試驗)에서 수량(收量)위주로 볼 때 임간초지(林間草地)의 적정시비수준(適正施肥水準)은 자연광조건(自然光條件)의 일반초지(一般草地)와 마찬가지로 표준비($N-P_2O_5-K_2O=28-20-24kg/10a$)시용인 것으로 나타났으나 경제성을 고려할 때 10a당 질소는 $20{\sim}28kg$, 인산 $10{\sim}15kg$, 칼리 $12{\sim}18kg$이 적합하다고 생각된다.