• 한국환경농학회지
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• 제7권2호
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• pp.146-152
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• 1988

도시 폐기물의 퇴비화 과정중 퇴비중의 질소 화합물 함량을 시기별로 조사한 결과 다음과 같다. 1. 총 질소, 유기성 질소 및 미생물 이용 가능 질소 함량은 거의 변화가 없었으며 미생물 이용 불가능 질소 함량은 약간 증가하였다. 그러나 총 질소, 유기성 질소 및 미생물 이용 가능 질소의 유효성분 함량은 감소하였으며 미생물 이용 불가능 질소의 유효성분 함량은 거의 일정하였다. 2. 암모늄태 질소 함량은 초기에 높았다가 퇴비화가 진행됨에 따라 감소 하였으며 이적을 한 후에는 다시 증가하다가 감소하였다. 3. 질산태 질소 함량은 암모늄태 질소 함량과 반대 경향을 보였다. 4. 유기물 중 유기성 질소 함량은 증가하였으며 초기에는 완만한 증가현상을 보이다가 9주와 21주 사이에 급격히 증가하였다. 5. $F{\"{o}}rster$ 방법에 의한 총 질소 함량이 Kjeldahl 방법에 의한 것보다 높았으며 Kjeldahl 방법에 의한 총 질소 함량이 $F{\"{o}}rster$ 방법에 의한 미생물 이용 가능 질소 함량보다 6% 높았다. 6. 30주 후 총 질소 손실량은 Kjeldahl 방법으로 측정한 결과 50% $F{\"{o}}rster$ 방법으로 측정한 결과 48% 이었으며 초기 2주 내에 급격한 질소 손실이 일어났다. 7 Kjeldahl 방법에 의한 총 질소, 미생물 이용 가능 질소, $F{\"{o}}rster$ 방법에 의한 총질소 및 미생물 이용 가능 질소 상호간에 유의적인 정(+)의 상관이 있었다.

• 한국해양환경ㆍ에너지학회지
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• 제17권2호
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• pp.90-103
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• 2014

2011년 9월에 동해의 수괴 분포와 용존 무기 및 유기 영양염의 분포 특성을 파악하였다. 수온, 염분, 용존산소의 분포를 통하여 연구해역의 수괴 기원은 WM(water mass)-I, WM-II, WM-III, WM-IV 등 4개의 대표적인 수괴로 구분되었으며, 그 성격은 각각 대마난류표층수, 대마난류중층수, 북한한류수, 동해고유수와 유사하였다. 용존 영양염의 경우, 용존 무기 질소(DIN; dissolved inorganic nitrogen)와 용존 무기 인(DIP; dissolved inorganic phosphorus)은 WM-IV에서 가장 높았으며, WM-III, WM-II, WM-I 순으로 나타났다. 반면에 용존 유기 질소(DON; dissolved organic nitrogen)와 용존 유기 인(DOP; dissolved organic phosphorus)은 무기 영양염과 상반되는 분포를 보였다. 연구해역에서 수괴 전체에 대한 DIN : DIP 비는 약 15.8로 Redfield ratio(16)에 근접한 수치를 보이고 있으나, 혼합층의 경우 5.3으로 무기질소가 식물플랑크톤 성장의 제한 요인으로 작용할 수 있는 것으로 보였다. 하지만 무기 질소가 제한된 혼합층에서 DON은 용존 총 질소(DTN; dissolved total nitrogen) 중 약 70%를 구성하였다. 따라서 풍부한 DON은 동해에서 식물플랑크톤의 성장을 위한 중요한 영양염 공급원으로 판단된다.

• 한국유기농업학회:학술대회논문집
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• 한국유기농학회 2011년도 상반기 국제 심포지엄
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• pp.117-127
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• 2011

The paper outlines farming systems, including organic, in the UK, and provides a context for the use of biological nitrogen (N) from legumes, especially clovers, and manure in organic grassland systems. As N is dynamic within organic ruminant/grassland systems its pathway is described, including its loss and resultant environmental impact. Improvements in the predictability of response to biological N, its role in reducing the carbon footprint of ruminant products and potential to improve its efficiency are discussed.

• 한국해양환경ㆍ에너지학회지
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• 제6권4호
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• pp.13-23
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• 2003

Organic carbon and nitrogen contents in suspended particulate matter (SPM) and surface sediments in seawater were measured in the Northern East China Sea in summer. The distribution of particulate organic carbon(POC) and particulate organic nitrogen(PON) were in the ranges of 54~481㎍/ℓ and 6~85㎍/ℓ, respectively, with relatively high level of concentrations in the western and southern sides of the study area. Also, there has been a significantly positive correlation between POC and PON, gradually increasing toward the deeper range of depth. Average C:N ratios of POC and PON of SPM were 6 in study area. The ratios of POC to PON of SPM increased as the range of depth increased, indicating nitrogen decomposes more rapidly than carbon and is considered to be influenced by the input of detritus from surface sediments. The distribution of total organic matter(TOM), total organic carbon(TOC) and total organic nitrogen(TON) in surface sediments were in the ranges of 3.1~9.6%, 0.282~0.635% and 0.022~0.069%, respectively, with relatively low range in the western and northern sides of the study area. The ratio of TOC to TON of surface sediments were in the range of 9.8~17.4(average of 13), strongly indicating the active role of the input from the terrestrial organic pollutants.

• 농업과학연구
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• 제42권4호
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• pp.431-437
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• 2015

자원순환 및 친환경 농업을 실천하는 농가가 증가함에 따라 유기물을 활용한 농경지 양분관리에 대한 필요성이 대두되고 있다. 질소 공급원으로 유기물을 시용했을 때 질소 공급효과에 대한 연구들을 정리한 결과는 다음과 같다. 농경지에 유기물을 시용했을 때 질소의 공급은 질소 순환에서 무기화 과정을 통해 이루어지기 때문에 작물의 단기적인 질소 이용률은 무기질 비료에 비해 낮다. 유기물의 질소 공급량은 유기물의 C/N율이 낮을수록 무기화율이 높아지므로 C/N율을 고려한 유기물 시용이 중요하다. 가축분 퇴비의 경우 축종별 분뇨 질소함량과 퇴비와 혼합된 부산물 종류에 따라 질소 무기화율이 달라질 수 있으며, 녹비는 작물 종류와 환원시기, 토양 양분조건 등에 따라 C/N율이 달라진다. 또한 적정량의 질소를 추천하기 위해서는 토양 중 유기태 질소로부터 가용화 될 수 있는 질소의 양을 측정하여야 한다. 지금까지 보고된 퇴비, 녹비에 대한 질소공급과 작물 생산성에 대한 연구결과는 재배 여건과 작물 종류 등에 따라 다르게 나타나 질소 공급을 위한 유기물 추천 모델을 구성하기 위한 기초자료로 활용하기에는 어려움이 있다. 유기물 추천 모델을 구성하기 위해서는 우선적으로 유기물질 종류별 질소 공급량에 대한 기초 데이터가 구축되어야 하며, 토양의 질소공급량을 평가할 수 있는 분석 방법의 구축이 필요하다.

• 한국물환경학회지
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• 제22권3호
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• pp.492-497
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• 2006

Feasibility of simultaneous removal of organic materials and nitrogen in the wastewater from fisheries processing plant was evaluated using entrapped mixed microbial cell (EMMC) process. The experiment was performed using activated sludge from municipal sewage treatment plant which was immobilized with gel matrix by cellulose triacetate. It was found the stable operation at the treatment system which is composed of anoxic and oxic tank, was possible when the organic and nitrogen loading rates were increased stepwise. The organic and nitrogen loading rates were conducted from 0.65 to $1.72kgCOD/m^3/d$ and from 0.119 to $0.317kg\;T-N/m^3/d$ with four steps, respectively. The maximum nitrogen loading rate which could satisfy the regulated effluent standard of nitrogen concentration, was $0.3kg\;T-N/m^3/d$. The removal efficiency of total nitrogen was decreased apparently as increasing nitrogen loading rates, whereas the removal efficiency of ammonium nitrogen was effective at the all tested nitrogen loading rates. Therefore, it was concluded that nitrification was efficient at the system. Nitrate was removed efficiently at the anoxic tank. whereas the nitrification efficiency at the oxic tank ranged 94.0% to 96.9% at the tested loading rates. The removal efficiencies of chemical oxygen demand (COD) and those of total nitrogen at the entire system ranged from 94.2% to 96.6% and 73.4% to 83.4%, respectively.

• 한국환경농학회지
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• 제30권1호
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• pp.1-8
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• 2011

BACKGROUND: With increasing public awareness to environment-friendly agriculture, many efforts have been run to develop organic farming technologies in Korea as of late 90s. The objective of this study was to investigate the effects of different organic farming practices on soil chemical properties and water quality in paddy fields. METHODS AND RESULTS: Total nitrogen (TN) and total phosphorus (TP) were monitored for a two-year period (2006 to 2007) from the study organic paddy fields located in Wan-ju, Jeonbuk Province in Korea. TN and TP of organic paddy water were gradually increased for 2~3 weeks after organic manure application and then gradually decreased afterward. The overall variation of TP in the paddy fields was much greater than that of TN. The phosphorus content in organic paddy field appeared to increase with the organic farming period. CONCLUSION(s): This indicates that long-term organic farming is likely to cause phosphorus accumulation in soils and increase vulnerability to rainfall runoff. Thus, appropriate phosphorus management needs to be implemented, particularly, to reduce excessive phosphorus supply owing to nitrogen-based determination of organic manure application amount.

• 한국환경과학회지
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• 제18권7호
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• pp.811-817
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• 2009

To determine changes in nitrogen contents and optimal rates as N fertilizer, we investigated nitrogen characteristics in the slurry in the respond to the application of 0, 0.5, and 1 g of ferrous sulfate or alum /25g of dairy slurry. Additions of ferrous sulfate or alum increase total nitrogen, inorganic nitrogen, available nitrogen, and predicted available nitrogen contents in dairy slurry, resulting in reduction in pH. The best results were found in the treatment with 0.5 g of ferrous sulfate or alum /25 g of dairy slurry. In conclusion, the use of ferrous sulfate or alum as on-farm amendment to dairy slurry should be represented an alternative to improve N in dairy slurry.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1615-1615
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• 2001

During the past ten years, Near Infrared Spectroscopy has been successfully applied to the analysis of a great variety of agriculture products. Previous works (Morra et al., 1991; Salgo et al., 1998) have shown the potential of this technology for soil analysis, estimating different parameters just with one single scan. The main advantages of NIR applications in soils are the speed of response, allowing the increase of the number of samples analysed to define a particular soil, and the instantaneous elaboration of recommendations for fertilization and soil amendment. Another advantage is to avoid the use of chemical reagents at all, being an environmentally safe technique. In this paper, we have studied a set of 129 soil samples selected from representative glasshouse soils from Southern Spain. The samples were dried, milled, and sieved to pass a 2 mm sieve and then analysed for organic carbon, total nitrogen, inorganic nitrogen (nitrate ammonium), hygroscopic humidity, pH and electrical conductivity in the 1:1 extract. NIR spectra of all samples were obtained in reflectance mode using a Foss NIR Systems 6500 spectrophotometer equipped with a spinning module. Calibration equations were developed for seven analytical parameters (ph, Total nitrogen, organic nitrogen, organic carbon, C/N ratio and Electric Conductivity). Preliminary results show good correlation coefficients and standard errors of cross validation in equations obtained for Organic Carbon, Organic Nitrogen, Total Nitrogen and C/N ratio. Calibrations for nitrates and nitrites, ammonia and electric conductivity were not acceptable. Calibration obtained for pH had an acceptable SECV, but the determination coefficient was found very poor probably due to the reduced range in reference values. Since the estimation of Organic Carbon and C/N ratio are acceptable NIIRS could be used as a fast method to assess the necessity of organic amendments in soils from Mediterranean regions where the low level of organic matter in soils constitutes an important agronomic problem. Furthermore, the possibility of a single and fast estimation of Total Nitrogen (tedious determination by modifications of the Kjeldahl procedure) could provide and interesting data to use in the estimation of nitrogen fertilizer rates by means of nitrogen balances.

• 환경생물
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• 제27권3호
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• pp.279-284
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• 2009

In order to understand food sources-metabolism for the pacific oyster (Crassostrea gigas), the stable isotope ratios of carbon (${\delta}^{13}C$) and nitrogen (${\delta}^{15}N$) of its gut, gill, and muscle as well as potential food sources (particulate organic matter, sedimentary organic matter, benthic microalgae, seagrass detritus) were determined in Dongdae Bay. Average ${\delta}^{13}C$ and ${\delta}^{15}N$ values reflect that oysters primarily fed on sedimentary organic matter as opposed to suspended organic matter during summer and winter seasons. However, the relatively enriched $^{15}N$ values of particulate organic matter (>$250{\mu}m$) and sedimentary organic matter in the summer may be due to the photosynthetic incorporation of $^{15}N$-enriched nitrogen (DIN) or the spawning events of bivalves. Specific oyster tissues (gut, gill, and muscle) revealed different metabolic pathways, which were determined through analysis of ${\delta}^{13}C$ and ${\delta}^{15}N$ in each organ. The present results suggest the determination of carbon and nitrogen stable isotopes to be a useful approach in ecological research related to the food sources- metabolism of Crassostrea gigas.