• 한국연초학회지
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• 제28권1호
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• pp.9-16
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• 2006

To get the informations of burley leaf, the chemical constituents, quality indices, leaf color and the effects of climatic factors on the physicochemical properties of leaf produced from 2000 to 2004 crop years at 6 growing areas were analysed. The average leaf chemical contents for 5 years were as follows ; nicotine 2.87%, total nitrogen 4.55%, and chlorine 0.57%. The nicotine content was low while total nitrogen was slightly high as compared with recommended contents(nicotine ; $3.0{\sim}3.5%$, total nitrogen; $4.0{\sim}4.5%$). The variations of physicochemical properties among crop years were high while those of growing areas were relatively low. The nicotine contents of upper leaves were positively correlated to the sunshine hours in June and negatively correlated to the rainfalls in June and July according to crop years. However the total nitrogen content of upper leaves were positively correlated to the rainfalls in July according to growing areas. The tan-tended colored leaves were produced under the high air temperature, drought and long sunshine weather condition while the buff-tended colored leaves were produced under the contra교 condition according to crop years. It is considered that the increasing of nicotine content of Lugs may be available to decrease the nitrogen number(nitrogen/nicotine ratio) of leaf tobacco.

• Journal of Plant Biology
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• 제17권1호
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• pp.15-21
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• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.

• 한국물환경학회지
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• 제39권5호
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• pp.390-395
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• 2023

The feasibility of applying the shortcut nitrogen removal process to treat livestock wastewater on individual farms was examined, and appropriate operating parameters were established. As a result,, it was determined that the nitrification reaction was carried out under 550 mg/L of ammonium nitrogen concentration, but it was less effective under conditions of high ammonia concentration. Consequently, it was confirmed that a partial injection of inflow water was necessary to minimize the effects of ammonia toxicity. Following the sequential batch reactor (SBR) operation results, it was difficult to achieve the effluent quality standard without an external carbon source. Also, selection of the appropriate hydraulic retention time was critical for the optimal SBR operation. Following the livestock farm application, with external carbon source injecting, the total nitrogen concentration in the effluent was 85.1 mg/L. This result revealed that the standard could be accomplished through a single treatment on individual livestock farms. The ratio of nitrite nitrogen to ammonia nitrogen in the effluent was verified to be suitable for implementing the anammox process with a 10 days of hydraulic retention time. This study demonstrated the potential applicability of process in the future. However, in order to apply to livestock farms, managing variations in wastewater load across individual farms and addressing reduced nitrogen oxidation efficiency during the winter season are crucial.

• 유기물자원화
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• 제12권1호
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• pp.84-93
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• 2004

본 연구는 생물학적 처리공정의 하나인 SBR을 이용하여, 양돈폐수중의 유기물과 질소, 인의 동시 제거를 목적으로 적정의 수리학적 체류시간(HRT)과 반응기간 중 교반/폭기 시간비(M/A) 및 적정의 교반/폭기 시간비에서의 외부탄소원의 주입기간(Injection Time)에 따른 변화에 따른 실험 결과로부터 다음과 같은 결론을 얻었다. (1) $NH_4{^+}-N$의 제거효율은 M/A가 0.0/22.0일 때(Run 1) 가장 효율이 좋았으며, 외부탄 소원을 주입했을 경우 탈질균의 증식으로 인해서 질산화가 잘 이루어지지 않기 때문에 주입시간이 길어질수록 증가하였다. T-N의 제거효율은 M/A가 증가할수록, 외부탄소원 주입시간이 길어질수록 증가하였다. (2) T-P의 제거효율은 운전조건에 따라 큰 차이를 보이고 있으며, M/A가 증가할수록 제거효율은 증가하였으며, 외부탄소원의 주입기간을 두고 보았을때, 주입기간을 짧게 할 경우 탈질균의 증식으로 인해서 탈질이 더 효율적으로 이루어지기 때문에 그 제거효율은 증가하였다. (3) 총 반응시간 22시간 중 M/A 16.5/5.5, 무산소 기간의 16.5시간 중 15시간동안 외부탄소원을 주입했을 경우(Run 4-1)의 운전조건에서 유기물 및 질소 제거에 가장 효율적이었다. 각각의 효율을 살펴보면, $COD_{Cr}$, $COD_{Mn}$ 그리고 $BOD_5$인 경우, 각각 90.6%, 87.7% 그리고 96.1%이고, T-N의 경우 86.6%, T-P인 경우는 84.5%로 나타났다.

• 환경위생공학
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• 제11권3호
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• pp.63-68
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• 1996

This study was to discuss limiting factors influenced on the removal efficiencies of nitrogenous compounds investigated using the polypropyrene media which was to attach microorganism in order to apply the fixed-biofilm process. The main limiting factors are the hydraulic retention time (HRT), C/N ratio, $COD/NO_{3}-N$ ratio and temperature. The hydraulic retention time HRT were 6, 8, 10, 12 hrs and the C/N ratio range was 2.5-9.5. The $COD/NO_{3}-N$ ratio range was 3.2-21.9 and the temperature were 15, 20, 25, 30, $35^{\circ}C$, respectively. The results of this study are summerized as follows. 1. Hydraulic retention time (HRT) to obtain removal efficiencies of T-N higher than 85% had to be 10 hrs above. 2. The removal efficiencies of T-N decreased at C/N ratio from 6.2 to 4.8 in this anoxic-contact aeration system. 3. Denitrification rate decreased at $COD/NO$_{3}$-N$ ratio from 8.0 to 5.0 4. As temperature increased, removal efficiencies of T-N increased.

• 한국초지조사료학회지
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• 제17권2호
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• pp.123-134
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• 1997

The effects of cutting 6equency and nitrogen fertilization on feed values of reed canarygrass were investigated in uncultivated rice paddy and the attemp was made to estimate the economical and efficient levels of nitrogen fertilization for the increased production of nutrients in reed canarygrass. The results are summarized as follows; 1. Crude protein(CP) content was higher at 1st cut of all treatments(12.5% in 3 cutting 6equency; 19, 7% in 4 cutting frequency; 22.5% in 5 cutting kquency). However, Total Digestible Nutrients(TDN) and Relative Feed Value(RFV) in 3 and 4 cutting 6equencies were higher at 3rd cut(63.5%, 126.8) and 4th cut(65.7%, 146.4) respectively in which the contents of Neutral Detergent Fiber(NDF) and Acid Detergent Fiber(ADF) were lowest. In 5 cutting frequency, 1st cut showed the highest TDN and RFV as 70.5% and 232.4 respectively. 2. The level of nitrogen fertilization affected CP content of reed canarygrass. Nitrogen fertilization of 120kgl halcut showed high CP contents of 11.4, 14.7 and 16.5% in 3, 4 and 5 cutting eequency respectively. In 3 and 4 cutting frequency, TDN and RFV were highest with nitrogen fertilization of 90kg/ha/cut where NDF and ADF were lowest, however those in 5 cutting frequency were highest with nitrogen fertilization of 30kg/ha/cut. 3. The yields of CP varied according to the number of cutting frequency and those were 0.45~0.65 in 3 cutting hquency, 0.35~0.50 in 4 cutting frequency, and 0.19~0.67tond/ha in 5 cutting 6equency respectively and TDN was 2.09~3.60, 1.64~2.77 and 0.73~2.96tons/ha respectively. 4. The ratios between the yields of CP and TDN were 5.48, 4.60 and 4.34 in 3, 4 and 5 cutting 6equency respectively and it indicates lower ratio in result of higher number of cutting 6equency. 5. Higher nitrogen fertilization increased the yields of CP and TDN. The yields of CP were higher in 5 cutting frequency as 1.55~2.62tons/ha than of 3(1.20~1.91tons/ha) and 4 cutting frequency(1.35-2.23tons/ha). The yields of TDN were 6.31~9.93, 5.99~9.99 and 7.16~10.57tons/ha in 3, 4 and 5 cutting frequency respectively. 6. The levels of nitrogen fertilization for high production efficiency of crude protein(kg CPYkg N) was estimated as 113.4~302.5kg/ha and it resulted in 1.44~2.09ton/ha of CP yields. The levels of nitrogen fertilization for high production efficiency of dry matter was 199.2-361.3kgha in which nitrogen were fertilized below 400kg/ha and it resulted in 1.64~2.17ton/ha of CP yields. 7. The levels of nitrogen fertilization for high production efficiency of total digestible nutrients(kg TDNYkg N) were 149.9~294.1kg/ha in 3 and 4 cutting kequency and it resulted in 8.66~8.89ton/ha of TDN yileds. With the levels of nitrogen fertilization for high production efficiency of dry matter of 199.2~361.3kg/ha, TDN yields were high as 8.77~9.94ton/ha.

• 한국토양비료학회지
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• 제16권1호
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• pp.50-55
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• 1983

화본과(禾本科) 및 두과사료작물(豆科飼料作物)의 단파(単播)와 혼파(混播)에서 중질소(重窒素)를 시용(施用)하여 시비질소(施肥窒素)의 작물별(作物別) 건물수량(乾物收量), 질소흡수량(窒素吸收量), 질소고정량(窒素固定量)에 대(対)한 질소(窒素)의 효과(効果)를 조사(調査)하였다. 1. 두과작물(豆科作物)에서 질소고정량(窒素固定量)은 alfalfa > red clover > birdsfoot trefoil의 순(順)이었으며 토양질소의존도(土壌窒素依存度)는 red clover가 가장 컸다. 2. 건물수량(乾物收量)에 대(対)한 질소시용효과(窒素施用効果)는 orchardgrass에서만 높이 인정(認定)되었고 alfalfa와 birdsfoot trefoil는 혼파(混播)의 경우 초기(初期)에만 인정(認定)되었다. 3. 건물수량(乾物收量)은 단파(単播)에서는 alfalfa > red clover > orchardgrass > birdsfoot trefoil의 순(順)이고 혼파(混播)에서는 orchardgrass + alfalfa > orchardgrass + red clover > orchardgrass + birdsfoot trefoil순(順)으로 나타났다. 4. 질소흡수량(窒素吸收量)은 전구(全区) 공(共)히 시비구(施肥区)가 무비구(無肥区)보다 증가(増加)하였고 단파시(単播時) alfalfa > red clover > orchardgrass > birdsfoot trefoil순(順)으로 작물별(作物別)로 흡수량(吸收量)의 차이를 보였다. 5. Orchardgrass의 질소흡수량(窒素吸收量)은 3:7의 red clover 혼파(混播) 시비구(施肥区)만 제외(除外)하고 시비(施肥)에 관계없이 파구(播区)가 단파구(単播區)보다 높았다.

• 한국작물학회지
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• 제53권spc호
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• pp.72-77
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• 2008

This study was carried out to determine the response of the rice yield and grain quality by rice leaf folder (RLF, Cnaphalocrocis medinalis G.) and identify the damages caused by different transplanting dates, nitrogen amounts and chlorophyll amounts (SPAD value) of rice leaf. As the damage degree of RLF was getting severer, the ripened grain rate and 1000-grain weight were decreased and due to the increasing of chalky rice rate the rate of head rice was reduced. Therefore, the yield of head rice was decreased by 36% in heavily damaged rice plant. Among the physicochemical characteristics, protein content of rice grain was increased but amylose content was reduced, consequently, the palatability was deteriorated in heavily damaged rice by RLF. The degree of damage of RLF was getting serious as transplanting date was delayed and as the amount of nitrogen was increased. In the relationship between the SPAD value and the damage degree of RLF, as the SPAD value was increased by nitrogen fertilizing, the damage degree was also increased exponential functionally.

• 한국축산시설환경학회지
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• 제3권1호
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• pp.13-18
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• 1997

This study was conducted to investigate the physicochemical changes during the aerobic composting of swine manure mixed with bulking agent, sawdust(v/v, 1:1), in a full-scale composting plant using rectangular escalator-aginated bed composting system. Physical and chemical properties were analyzed on the samples which were collected at 5, 15, and 25 day of composting, curing and final step. The results of this study were summarized as follows; 1. Moisture and K2O content, and pH of final step were higher than those of 5th day of composting (p＜0.05). 2. Ammonium nitrogen, total organic corbon and organic matter content, and electrical conductivity(EC) were significantly decreased (p＜0.05) but nitrate nitrogen, ash and P2O5 content increased(p＜0.05) throughout the aerobic composting process. 3. Total organic carbon per total nitrogen(C/N) and total organic matter per total nitrogen(OM/N) ratio were significantly decreased throughout the aerobic composting process(p＜0.05). 4. Physical and chemical properties of swine manure were varied by aerobic fermentation using rectangular escalor-aginated bed composting system.

• 한국환경과학회지
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• 제6권5호
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• pp.521-529
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• 1997

In the study, we Investigated the behavior and removal efficiency of organics, nitrogen. phosphorus with operating conditions in SBRs. Substrate used was synthetic wastewater in which the ratio of $COD_{cr}$. : N : P was 100 : 12 : 2. The cycling the in SBRs was adjusted at 6 hours and 8 hours, and then certainly Included anaerobic and aerobic conditions. Also, for each cycling time. we performed 2 series of experiment simultaneously which was set up 10 days and 20 days as SRT. The removal efficiency of $COD_{cr}$. was over 97% in all operating conditions. In the 6 hours cycling time, the removal efficiency of $PO_4^{3-}-P$ reached almost 100% in steady state. And then we could observe a typical phonemena of phosphorus release and uptake, and the removal efficiency of N was 67%, Residual N source was almost TKN and most of the rest remained as $NO_2-N$. Also the difference in both SRTs was not observed practically. In the 8 hours cycling time, dissolution of sludge appeared. and, $PO_4^{3-}-P was not nearly removed but nitrogen was removed up to 75%, And the residual nitrogen was accumulated as $NO_2^--N$.