• 한국농공학회논문집
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• 제48권3호
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• pp.97-106
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• 2006

The pollutant concentrations at experimental paddy plots with three (excessive, standard, reduced) different fertilization rates were investigated during 2001-2002 irrigation seasons. Mean concentrations of pollutants in ponded water were not significantly different among three experimental plots, but the T-N concentrations in percolated water significantly depended on fertilization rates. The T-N, T-P and $COD_{Cr}$, concentrations in ponded water during early irrigation season (late May to mid-June) were much higher than those during later irrigation season likely due to fertilization and low uptake by young rice crops. The T-N concentrations decreased but the concentrations of T-P and $COD_{Cr}$, increased three days after tillering fertilization. The removal rates of T-N by paddy plots were $0.13-0.16g/m^2{\cdot}d$ for an excessive fertilization plot, $0.08-0.25g/m^2{\cdot}d$ for a standard fertilization plot, and $0.03-0.34g/m^2{\cdot}d$ for a reduced fertilization plot three days after tillering fertilization. On the other hand, T-P and $COD_{Cr}$, were released three days after tillering fertilization.

• 한국농공학회논문집
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• 제66권5호
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• pp.15-27
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• 2024

Agriculture is recognized as an important anthropogenic cause of non-point source loads. Improved understanding of non-point source loads according to fertilization practices can promote climate change and eutrophication mitigation. Thus, this study evaluated the impact of conventional and standard fertilization practices on non-point pollution (NPP) loads in a dual-cropping system, utilizing the Agricultural Policy/Environmental eXtender (APEX) model. Our research objectives were twofold: firstly, to calibrate and validate the APEX model with observed data through experiments from 2018 to 2023; and secondly, to compare the NPP loads under conventional and standard fertilization practices. The model calibration and validation showed satisfactory performance in simulating nitrogen (N) and phosphorus (P) loads, illustrating the model's applicability in a Korean agricultural setting. The simulation results under conventional fertilization practices revealed significantly higher NPP loads compared to the standard fertilization, with P loads under conventional practices being notably higher. Our findings emphasize the crucial role of recommended fertilization practices in reducing non-point source pollution. By providing a quantitative assessment of NPP loads under different fertilization practices, this study contributes valuable information to sustainable nutrient management in agricultural systems facing the dual challenges of climate change and environmental conservation.

• 한국작물학회지
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• 제56권2호
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• pp.140-145
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• 2011

벼에 대한 SCB 액비의 활용방법을 구명하기 위하여 기 추 비 시용량을 달리 처리한 후 쌀 수량 및 토양환경에 미치는 영향 등을 검토한 결과는 다음과 같다. 논토양의 화학성은 규산을 제외한 액비시용구가 무시용구에 비하여 높았으나 시험 전 후 간에는 큰 차이가 없었다. 액비시용 후 토양 중 $NH_4$-N함량은 2일 이내 균평작업으로 논 전체에 균일한 농도를 유지하였다. 액비분시에 따른 토양 중 $NH_4$-N와 $NO_3$-N함량은 이앙 후부터는 초기에는 화학비료 관행시비구와 액비 기비 100%처리에서 높았으나 분얼감수기 이후에는 모든 처리가 유사하였다. 토양침출수중 $NO_3$-N함량은 액비기비70%+수비30%시용에서 관행시비구보다 약간 낮은 함량을 보였다. 액비 분시에 따른 쌀 수량은 관행시비구보다 액비 기비 100%처리에서 약간 낮았으나 액비 기비70%+수비30%에서 관행시비구와 대등하였으며 나머지 액비 처리구에서도 큰 차이가 없었다. 쌀 품위는 무 시용구와 액비 기비100%에서 완전립율이 높고, 단백질함량이 낮았으나 액비기비70%+수비30%에서 관행시비구와 유사하였다. 따라서 SCB액비를 이용하여 벼 재배할 경우 액비기비70%와 수비30%시용으로 화학비료 사용을 대체 할 수 있을 것으로 판단된다.

• 한국작물학회지
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• 제51권5호
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• pp.445-450
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• 2006

본 연구에서는 질소 시비수준이 생육시기별 식물체 및 종실에서 isoflavone함량에 미치는 영향을 구명하기 위하여 고속액체크로마토그래피(HPLC)를 이용하여 생육시기에 따른 식물체에서 isoflavone을 분석한 결과를 요약하면 다음과 같다. 1. 질소시비 수준에 따른 일반생육은 50%증비구가 다른 처리에 비하여 가장 좋았는데, 엽수 및 엽면적이 표준비의 72.7개, $619.7cm^{2}$에 비하여 81.9개와 $723cm^{2}$으로 증가하였다. 2. 수량 관련 형질 중에서 협수 및 종실수는 50%증비에서 개체당 31.9개와 72.3개로 가장 많았으며, 수량도 246 kg/10a로 다른 시비구에 비하여 가장 높았다. 무비와 N무비구에서는 협수가 24.9개/개체와 25.1개/개체, 립수는 60.3개/개체과 51.1개/개체, 수량은 181.0 kg/10a과 178.0 kg/10a으로 낮았다. 3. 생육시기에 따른 isoflavone 함량은 잎, 줄기, 뿌리에서 개화이후부터 립비대기(R5)까지는 감소하다가 이후 수확기(R7)까지 다시 증가하였다. 4. 식물체 부위별 isoflavone 함량은 뿌리에서 가장 높은 값을 나타내었다. 5. 시비수준에 따른 종실의 isoflavone 함량은 무비, N무비 및 50% 감비의 경우가 표준비나 증비보다 다소 높은 함량을 나타내었다.

• Environmental Analysis Health and Toxicology
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• 제24권1호
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• pp.9-16
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• 2009

Effects of salinity and standard toxic metals on fertilization and embryo development rates were investigated in the sea urchin, Hemicentrotus pulcherrimus. Spawning was induced by injecting $1{\sim}2$ mL of 0.5 M KCl into the coelomic cavity. Males released white or cream-colored sperms and females released yellow or orange-colored eggs. The fertilization rate was below 30% when salinity was 20 psu and lower, but was almost above 90% when salinity was 25 psu and higher. The embryo development rate was below 60% when salinity was 25 psu and lower, but was above 80% when salinity was between 30 and 35 psu. The fertilization and embryo development rates in the control condition(not including Cu and Cd) were greater than 90%, but decreased a high negative correlation with the increasing of Cu(r=-0.80, r=-0.78) and Cd(r=-0.90, r=-0.82) concentrations, respectively. The fertilization and embryo development rates were significantly inhibited in the addition of Cu($EC_{50}$=17.30 ppb, $EC_{50}$=10.32 ppb) and Cd($EC_{50}$=364.57 ppb, $EC_{50}$=244.04 ppb), respectively. These results suggest that salinity concentrations for successful fertilization and normal embryogenesis of H. pulcherrimus are above 25 psu and 30 psu, respectively, and the biological assays of fertilization and embryo development rates using H. pulcherrimus are useful methods for the ecological toxicity test of marine pollution elements.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.106-106
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• 2022

An appropriate amount of nitrogen fertilizer input during rice cultivation is essential for rice growth, quality control, and reduction of greenhouse gases in paddy fields. Therefore, it is necessary to develop a technology that can check whether an appropriate amount of fertilizer is applied in paddy fields. In this study, we tried to derive a method for diagnosing nitrogen fertilization level using spectroscopic diagnosis, physiological analysis, and molecular indicator genes. Nitrogen fertilization treatment was performed in a greenhouse by dividing into five treatment conditions: no fertilization (N0), low fertilization (N0.5), standard fertilization (N1.0), excessive fertilization (N1.5), and double fertilization (N2.0), respectively. Growth characteristics analysis was investigated by nitrogen fertilization conditions and growth stages, and the height of the canopy was analyzed using a laser scanner. Physiological and spectroscopic analyses were performed by analyzing chlorophyll and sugar contents and measuring SPAD and leaf spectrometer on rice leaves. In addition, real-time PCR experiment was performed to check the relative expression levels of several known nitrogen metabolism related genes. These results suggest that spectroscopic techniques can be helpful in diagnosing the level of nitrogen fertilization in rice paddy fields.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.451-455
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• 2001

This study was performed to examine water and nutrient balance during rice cropping period using difference fertilization paddy plot in ground water irrigation region. The experimental rice paddy consist of three plot, Treatment of Excess fertilization(TEF) and Treatment of Standard Fertilization(TSF) and Treatment of Reduce Fertilization(TRF). As result, input amount to rice paddy was almost rainfall and output was direct runoff through drainage. nutrient input amount was upper paddy in case COD and fertilization in case Total nitrogen and total phosphorus, and output was drainage in all nutrient.

• 한국환경과학회지
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• 제17권7호
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• pp.775-781
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• 2008

Effects of salinity and standard toxic metals on fertilization and embryo development rates were investigated in the sea urchin, Strongylocentrotus nudus. Spawning was induced by injecting 1ml of 0.5 M KCl into the coelomic cavity. The fertilization and embryo development rates were below 20% when salinity was 25 psu or lower, but were above 90% when salinity was between 30 and 35 psu. The fertilization and embryo development rates in the control condition (not including Cu and Cd) were greater than 90%, but decreased with a high negative correlation (r) of 0.89 and 0.91 with the increasing of Cu and Cd concentrations, respectively. These results suggest that salinity concentrations for successful fertilization and normal embryogenesis of S. nudus are between 30 and 35 psu, and the biological assays of fertilization and embryo development rates using S. nudus are useful methods for the ecological toxicity test of marine pollution elements.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.121-121
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• 2022

When 7 kg·10a^-1, which is less than the nitrogen standard application amount of 9 kg·10a^-1, is applied, the protein content is lowered and the palatibility is improved. In order to examine the applicability of nitrogen fertilization of 7 kg·10a^-1 nationwide, soil samples were collected from 240 paddy fields in 8 provinces in 2021, and the organic matter content, effective phosphoric acid, and effective silicic acid were analyzed for each sample. As a result of one-way ANOVA analysis between samples collected for each province, there was no significant difference in the content of organic matter, effective phosphoric acid, and effective silicic acid except for some provinces. The contents of organic matter was higher than the appropriate level(25 ~ 30 g·kg^-1) except for Gyeongsangbuk-do, the effective phosphoric acid was higher than the appropriate level(80~120 mg·kg^-1) in all provinces, and the effective silicic acid was lower than the appropriate level(157 ~ 180 mg·kg^-1) except for Gyeonggi-do, Jeollanam-do and Gyeongsangnam-do. As a result of analyzing the recommended fertilization amount based on the nitrogen application amount of 7 kg·10a^-1, 68.3% ofthe 240 samples were able to give nitrogen fertilizer less than 7.5 kg·10a^-1, and the rest had to be given more than that to satisfy the standard fertilization amount. As a result of this study, 68.3% of rice paddies nationwide can be cultivated with a standard fertilization amount of 7 kg·10a^-1, however it was thought that continuous nutrient management would be required for other paddies.

• 한국초지조사료학회지
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• 제24권2호
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• pp.171-176
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• 2004

유기조사료 생산을 위한 방목초지의 역할을 구명하기 위해 2000년부터 2002년까지 경기도 수원시 소재 축산기술연구소에서 수행되었다. 유기재배에 따른 목초의 생산성을 구명하기 위해 대조구(표준관리), 친환경구, 유기구를 처리구로 하여 수행되었다. 그 결과는 다음과 같다. 1. 건물수량은 대조구, 친환경구, 유기구의 순으로 많았으나, 유기구와 대조구의 수량차이가 14% 정도로 작았다. 2. 사료가치와 식생에서는 큰 차이가 없었다. 위 시험의 결과 방목초지는 유기적 재배에서도 양호한 상태로 유지되어 초지는 유기조사료 생산에 적합한 작목으로 판명되었다.