• 한국연초학회지
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• 제18권1호
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• pp.49-53
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• 1996

This experiment was carried out to study the effect of oxygen on chemical composition and physical properties of tobacco leaves during flue-curing. The results obtained were as follows: Starch content decreased and sucrose content increased with increasing oxygen supply during curing. Glucose and fructose of the cured leaves showed high content at the 5-10% oxygen supply. Amino-N and nitrate-N increased with increasing oxygen supply. Total nitrogen and NH4-N showed the lowest value at the 5-10% and 10-15% oxygen supply in the cutters and leaf, respectively. Chlorophyll and chlorogenic acid increased, and total volatile base decreased with increasing oxygen supply. The activity of α-amylase increased at the latter period of flue-curing, and the maximum activity point were delayed 12 hours with increasing oxygen supply. Shatter index of cured leaves decreased with increasing oxygen supply. It was desirable to supply oxygen during flue-curing for the improvement of chemical and physical properties such as starch, total sugar, chlorogenic acid, and shatter index of cured leaves.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.651-656
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• 1999

This study was carried out to investigate the paddy soil and water quality in Boryung freshwater reservoir watershed during the non-cropping season. Soil pH of the Boryung freshwater reservoir watershed were 5.39∼5.78. Total-N and P contents were high by the accumulation of chemical fertilizer partly. Heavy metal content of paddy soils were natural background level. Water pH of the Boryung freshwater reservoir watershed ranged from 6.82 to 8.64. Total-N content affected by a livestock wastes and sewage water were the higher than that of others and total-P content showed below 0.1mg/L. Nitrate nitrogen contents was very high according to the influence a livestock waste and sewage water partly. Heavy metal contents of wateers were natural background level.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.157-164
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• 2021

Smart agriculture requires sensing systems which are fundamental for precision agriculture. Adequate and appropriate water and nutrient supply not only improves crop productivity but also benefit to environment. However, there is no available soil sensor to continuously monitor nutrient status in soil. Electrical conductivity (EC) of soil is affected by ion contents in soil and can be used to evaluate nutrient contents in soil. Comparison of various commercial EC sensors showed similar water content and EC values at water content less than 20%. Soil EC values measured by sensors decreased with decreasing soil water content and linearly correlated with soil water content. EC values measured by soil sensor were highly correlated with water soluble nutrient contents such as Ca, K, Mg and N in soil indicating that the soil EC sensor can be used for monitoring changes in plant available nutrients in soil.

• 한국패류학회지
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• 제24권3호
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• pp.243-251
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• 2008

진주의 감별기법상 UV-Vis의 흡수 스펙트럼 분석과 반사율 분석은 흑진주의 색깔이 자연 그대로인지 아니면 처리에 의한 결과인지를 구별하는데 중요한 요소가 된다. 또한 ED-XRF을 이용한 미량 원소 분석은 진주가 해수산인지 담수산인지 여부와 은염 또는 염색 처리 유무를 판단하는데 이용될 수 있다. 본 연구에서는 은염 또는 염색 처리되지 않은 여러 종류(담수양식진주, 아코야양식진주, 타히티흑양식진주)의 진주에 은염처리를 한 결과, 은 이온 고유의 스펙트럼이 진주 고유의 스펙트럼에 영향을 주어 UV-Vis흡수 스펙트럼이 변화되었다. 또한 반사율도 은염처리하기 전보다 낮아짐을 알 수 있었다. 특히 자연 색상의 타히티흑양식진주의 경우 400 nm, 500nm, 700 nm의 고유 흡수 스펙트럼을 갖고 있었으며, 자연색상의 담수흑양식진주의 경우 380-400 nm, 480-500 nm 두 개의 특징적인 흡수 스펙트럼으로 나타났다. 자연 색상의 담수흑진주에서는 자연 색상의 타히티흑진주와는 달리 700nm의 흡수 스펙트럼이 관찰되지 않았다. 직접 은염처리한 진주 9 개를 ED-XRF를 이용하여 분석한 결과, 처리시간이 증가함에 따라 진주 층에 침투된 은의 함량이 점차로 증가했음을 알 수 있었다. 또한 시중에서 구입한 흑진주 18 개를 분석한 결과, 은 이온의 상대 함유량이 약 0.1%를 경계로 은염 또는 염색 처리 여부를 판단하는 데 도움을 줄 수 있을 것으로 생각되었다.

• 한국유기농업학회지
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• 제10권2호
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• pp.95-109
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• 2002

유기농업 농가에서 사용하는 발효퇴비에 작물보호제와 생육촉진의 효과가 있다는 해초류를 0.05%, 0.25%, 1%, 5%혼합하여 그 기능성과 혼합비율을 구명하고자 배추(불암 3호)를 대상으로 작물재배 시험을 대형 lysimeter에서 실시하였다. 갈색해초를 혼합한 발효퇴비에 대한 작물생육, 수량 및 비타민 C함량, 당도 및 질산염 함량을 검토한 결과를 요약하면 다음과 같다. 1. 배추엽장은 해초를 혼합하지 많은 퇴비단독시용구에 비해 해초를 시용하였을 때 점차 길어지는 경향을 나타내 배추 생육촉진에 크게 효과가 있는 것으로 나타났다. 엽폭도 해초류 첨가구가 퇴비단독구에 비해 훨씬 크게 나타났다. 구폭도 해초 첨가에 따라 증가하는 경향을 나타내었으나, 해초 0.25%혼합구에서 2.07 cm을 나타내 가장 컸으며, 이후에는 해초 혼합비율이 높아도 구폭은 오히려 줄어들었다. 엽수 역시 0.25%의 해초혼합구에서 가장 높았다. 2. 해초를 혼합한 퇴비시용은 배추 생체 중 증가에 크게 영향하여 해초류 혼합비율이 증가할수록 생체중이 증가하였고 외부엽의 중륵무게에도 긍정적 영향을 나타내었다. 3. 엽록소 함량은 퇴비단독구에 비해 해초처리구에서 다소 높았으나 해초혼합비율 증가에 따른 엽록소 함량의 증가폭은 14%내외에 그쳐 그리 크지 않았다. 해초류 첨가는 배추의 엽신의 당도에는 긍정적인 영향을 나타내었으나, 중륵의 당도에는 해초 0.05%혼합구을 제외하고 모두 부정적인 영향을 나타내었다. 4. 해초류 첨가는 비타민C 함량에서 엽신과 중륵에서 모두 긍정적인 영향을 나타내었다. 그러나 비타민C 함량이 해초 1%혼합구 처리시 엽신에서 가장 많았고, 중륵의 비타민C 함량은 0.05%혼합구에서 가장 높았다. 5. 퇴비단독구의 질산염 함량은 중륵에서 5,138ppm이었다가, 해초 0.05%혼합구에서 2,765ppm으로 크게 낮아졌으며, 해초 1%혼합구에서 536ppm수준으로 크게 낮아져 해초류를 첨가 시비처리구에서의 질산염 저감효과가 뚜렷히 나타났다. 따라서 해초를 혼합한 퇴비는 향후 채소재배농가에게 질산염 저감용 기능성 퇴비로 활용될 수 있을 것으로 판단되었다.

• 한국작물학회지
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• 제42권5호
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• pp.515-521
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• 1997

질소의 형태를 질산태(NO$_3$$^{-}$-N), 암모니아태(NH$_4$$^{＋}$-N) 그리고 질산태와 암모니아태(NO$_3$$^{-}$-N ＋ NH$_4$$^{＋}$-N)를 혼합한 양액 하에서 수경재배하여 담배의 생육단계별 질소이용에 따른 흡수 양상과 생육 및 nitrate reductase, glutamine synthetase 효소활성을 평가하여 질소 시비 유형에 따른 체내 질소대사의 기초자료를 제공하고져 축행한 결과는 다음과 같다. 질소의 형태별 생육은 NO$_3$$^{-}$-N, NH$_4$$^{＋}$-N 단독 처리구보다 혼합처리구에서 지상 및 지하부의 생육이 좋았고, NH$_4$$^{＋}$-N 처리구에서는 암모늄 독성에 의해 생육이 극히 불량하였다. 생육단계별 양액의 pH 변화는 NO$_3$$^{-}$-N 처리구에서 이식 초기부터 이식 후 40일까지 증가하였고 NH$_4$$^{＋}$-N 처리구에서는 이식 후 20일에 pH 3.42, 혼합처리구에서는 이식 후 30일에 pH 3.64까지 떨어졌다가 증가하였다. 혼합처리구의 질소흡수반응은 생육초기에서는 NH$_4$$^{＋}$-N의 흡수를 우선하고 생육중기부터 NO$_3$$^{-}$-N 흡수가 증가하여 흡수 양상을 달리하였다. 생육시기에 따라 흡수형태도 NO$_3$$^{-}$-N와 NH$_4$$^{＋}$-N 사이의 상대적인 비율에 의해 크게 영향을 미쳤다. 엽록소와 가용성 단백질은 혼합처리구에서 전질소는 NH$_4$$^{＋}$-N 처리구에서 높았고, 특히 NH$_4$$^{＋}$-N 질소를 시비하였을 때는 질소함량이 증가하였다. 질산함량이 증가하였다. 질산함량은 NO$_3$$^{-}$-N 처리구에서 암모니아함량은 NH$_4$$^{＋}$-N 처리구에서 높았고, 산소 활성은 혼합처리구에서 nitrate reductase와 glutamine synthetase 활성이 높았다.

• 한국입자에어로졸학회지
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• 제6권4호
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• pp.151-164
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• 2010

Inorganic ions and water are major components of ambient fine particles. Water content in fine particles is mainly determined by ambient meteorological conditions and the concentrations of hygroscopic species such as inorganic ions. Thus, to reduce fine particle mass concentration, it is important to accurately estimate the relationship between water content and the concentration of ions in fine particles. Water content in fine particles in Seoul are estimated by using a gas/particle equilibrium model to understand the characteristics of fine particle mass concentration. In addition, sensitivity of fine particle mass concentration to the changes of particulate ionic species (sulfate, nitrate, and ammonium) is estimated. It was found that water content in Seoul is mostly determined by the concentrations of the hygroscopic ionic species, especially, sulfate and ammonium, and ambient relative humidity.

• Asian-Australasian Journal of Animal Sciences
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• 제24권3호
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• pp.439-448
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• 2011

Oxalic acid is synthesized by a wide range of plants. A few of them are forage plants that can cause oxalate poisoning in ruminants under certain conditions. In this paper, the role of some agronomic, climatic and genetic factors in minimizing oxalate accumulation in forage plants has been discussed. Research indicates that the content of oxalate in forage can be controlled by fertilizer application. For example, nitrate application resulted in higher contents of soluble and insoluble oxalates than ammonium application. With an increased rate of potassium application, soluble oxalate content showed an increasing trend and insoluble oxalate content showed a decreasing trend. With an increased rate of calcium application, soluble oxalate content showed a decreasing trend and insoluble oxalate content showed a reverse trend. Other agronomic factors such as growing season, harvesting practices, plant maturity, plant species, plant variety and plant parts can also have a large effect on oxalate accumulation. However, the potential benefits of the above approaches for improving forage quality have not been fully exploited. In addition, there is still insufficient information to fully utilize means (e.g. plant nutrients, season and soil moisture) to minimize oxalate accumulation in forage plants. Therefore, more research is required for a better understanding of the interactions between oxalate and the above-mentioned factors in forage plants.

• Journal of Plant Biology
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• 제7권1호
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• pp.5-10
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• 1964

The effects of briquette ashes on the growth of vegetable (cabbage, lettuce, spinach and radish) and their fresh weight under the culture of the soil mixed with the briquette ashes, and on the chemical properties of the soil were investigated. The growth rate of these palnts and chemical properteis of the soil has shown some influence due to different concentration of briquette ashes added to the soil. The increase of growth in cabbage and lettuce was remarkably found by the plot treated with 1/50 concentration of briquette ashes. The fresh weight of vegetable plants was increased with high concentration of briquette ashes, but if the concentration of briquette ashes was too high, it was rather depressed. Chemical properties in the soil after cultivation of the plants were more depressed than before cultivation. In contrast the available nitrogen content in the soil after cultivation was more increased than before cultivation of the plants. The reduction of available nitrogen and nitrate nitrogen was associated with the increasing intensity of briquette ashes, but available phosphorus content was increased with high concentration of briquette ashes, though its content was not so high as the results obtained by Han(8). The values of total exchangeable base and pH in the soils treated with briquette ashes were increased with a high degree of the concentration of ashes. The value of pH was not significant, and pH value of lime plots was higher than that of briquette ashes. The average value of the water content did not show any difference, and the difference of the content of organic matter in the soil in which different vegetable grew into the plots reached to the significance of a 5% level.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 추계학술발표회 요지
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• pp.214-215
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• 2005