• 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.

• Weed & Turfgrass Science
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• 제3권2호
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• pp.137-142
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• 2014

본 연구는 규산질 비료와 질소 비료 혼용이 한국잔디의 생육과 질소비료 효율에 미치는 영향을 알아보기 위해 수행하였다. 한국잔디의 초장, 지상부, 포복경과 지하부의 생체중과 건물중, 지상부 개체수, 포복경 길이는 규산질 비료 400 kg/10a와 질소비료 24 kg/10a을 혼합시비 하였을 때 질소비료의 24 kg/10a 단용처리구보다 증가하였고, 규산질 비료와 질소비료 18 kg/10a은 질소비료의 24 kg/10a 단용 처리구와 유의성이 없었다. 규산질 비료와 질소비료를 혼합하여 시비했을 경우 질소비료 약 25-30% 절감효과가 있는 것으로 판단되었으며, 토양 내 유효 규산과 유기물의 함량은 규산질 비료 시비를 하지 않은 것보다 시비를 하였을 때 더 높게 나타나 규산질 비료가 한국잔디의 생장과 밀도를 높였으며 토양의 화학적 특성에 중요한 요소로 작용하였다.

• 한국토양비료학회지
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• 제49권1호
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• pp.60-65
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• 2016

The main objective of this research was to estimate the total mass of nitrogen discharged from various sources in paddy field area of South Korea in 2010 and 2013. Input and output budgets for nitrogen were estimated by mass balance approach. The mass balance approach reduces the effect of flow variations, and the large scale approach minimizes local effects, resulting in easier and faster establishment of strategy for nonpoint pollution problems. Nitrogen inputs were chemical fertilizer, compost, atmospheric deposition, biological fixation, and agricultural water, while crop uptake, denitrification, volatilization, and infiltration were nitrogen outputs. The estimated total nitrogen inputs for paddy field in South Korea were $266,211ton\;yr^{-1}$, $260,729ton\;yr^{-1}$, while those of total nitrogen outputs were $168,463ton\;yr^{-1}$, $164,994ton\;yr^{-1}$ in 2010 and 2013, respectively. Annual amounts of potential nitrogen outflow from paddy field were $97,748ton\;yr^{-1}$, $95,735ton\;yr^{-1}$ in 2010 and 2013. Also, annual rate of potential nitrogen outflow were 36.7%, 36.7% in 2010 and 2013, respectively.

• Journal of Applied Biological Chemistry
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• 제62권1호
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• pp.67-71
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• 2019

All countries, including Korea, are currently experiencing the effect of rapid climate change. As a result, the cultivation area of many crops including wheat is changing, or productivity is falling sharply. If enough nitrogen is present in the soil, the increase in atmospheric carbon dioxide due to the greenhouse effect can lead to increased photosynthesis of plants, resulting in increased productivity. By contrast, a low proportion of nitrogen in soil does not increase production, often leading to the use of nitrogen fertilizers to increase crop productivity: this causes serious environmental pollution due to the leakage of nitrogen fertilizers used by crops. Increasing the understanding of the molecular level of the plant nitrogen use efficiency mechanism may contribute to increased productivity of crops and reduced of environmental pollution by nitrogen. In Korea, cultivars have developed 35 kinds of wheat, such as 'keumgang' and 'Chokyeong', which can be used for specific purposes such as baking or noodles. In this study we investigate 'keumgang' and 'Chokyeong' in order to elucidate the mechanism of nitrogen use ability of wheat and contribute to the reduction of environmental pollution by providing guidelines for the proper use of nitrogenous fertilizer.

• Applied Biological Chemistry
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• 제27권
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• pp.56-67
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• 1984

As in many other country, the use of organic matter in Korea has long history. Farmers understand the value of organic matter as the source of plant nutrient and soil improving agent in general. Since 50 years ago, the sources of organic matter in paddy soils were compost, rice and barly straw, green manure, animal waste, fish and beancake, etc.. Application of green manures such as vetch and chinese milk vetch showed no significant effect on the yield of brown rice in paddy soil. On the other hand, the effects of compost and rice straw showed more significant on the yield of brown rice in paddy soil. Application of rice straw in rice cultivation is commonly made at different times between harvest, early spring and several weeks before transplanting. Considering the suitable paddy soil for application of rice straw under well to moderately well drained soil, the yield was pronounced more than poorly drained soil. Based on laboratory and field experimants, application of rice straw promoted the decrease of oxidation-reduction potential in well to moderately well drained soil. This results to be enhanced the release of some mineral nutrients,. such as potassium, calcium, silicon, and increase of availability of soil phosphorus. In the field experiments, results obtained from nitrogen fraction on the immobilization-mineralization of the tracer nitrogen applied in paddy soil,the amount and index of organic nitrogen incoporated in soil was more pronounced in rice straw application than control. Rice straw and its transformation products incoporated in the soil, provided the inflow of energy necessary to maintain heterotrophic microbes activities. Rice straw and its transformation products, especially soluble carbohydrate, enhanced the population of free-living heterotrophic $N_2$ - fixing microbes. Moreover, rice straw and its transformation products in paddy soil, enhanced the activities of soil enzymes such as dehydrogenase and urease.

• 한국토양비료학회지
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• 제29권1호
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• pp.3-7
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• 1996

본(本) 연구(硏究)는 벼 무논골뿌림 직파재배(直播栽培)에서 수비질소(穗肥窒素)의 시용시기(施用時期)와 시용량(施用量)에 따른 질소흡수량(窒素吸收量) 및 이용율(利用率)에 미치는 영향(影響)과 수량성(收量性) 변이(變異)를 조사(調査)기 위하여 호남평야지(湖南平野地) 대표토양(代表土壤)인 전북통(全北統)에서 요소(尿素)를 공시(供試) 비종(肥種)으로 하여 수비시용효과(穗肥施用效果)를 시험(試驗)한 결과(結果)는 다음과 같다. 1. 식물체(植物體)의 수비질소(穗肥窒素) 흡수량(吸收量)과 이용율(利用率)은 출수전(出穗前) 20일 시용구(施用區)에서 가장 높았다. 2. 수비질소(穗肥窒素)의 손실량(損失量)은 20%감비구(減肥區)에서 시용시기(施用時期)가 빠를수록 적었다. 3. 간장(稈長) 및 하위절간장(下位節間長)(4절(節)+5절(節))은 수비시용시기(穗肥施用時期)가 빠를수록 길었으며, 도복지수(倒伏指數)는 시용시기(施用時期)가 빠를수록 그리고 시비량(施肥量)이 많을수록 증가(增加)하였다. 4. 등열율(登熱率) 및 천립중(千粒重)은 수비시용시기(穗肥施用時期)가 빠를수록 저하(低下)하였고 시용량(施用量)이 적을수록 증가(增加)하였으며 $m^2$당수수(當穗數)와 입수(粒數)는 출수전(出穗前) 10일 시용구(施用區)에서 현저(顯著)히 감소(減少)하였다. 5. 쌀수량(收量)은 출수전(出穗前) 20일의 전량시비구(全量施肥區)에서 관행구(慣行區)인 출수전(出穗前) 25일 33kg/ha 시용구에 비하여 3% 증수(增收)하였고 20% 감비구(減肥區)와 출수전(出穗前) 15일의 전량시용구(全量施用區)의 수량(收量)은 관행(慣行)과 유사한 경향(傾向)이었다.

• 한국토양비료학회지
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• 제42권3호
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• pp.152-159
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• 2009

혼합유기질비료 시용 후 벼 재배시 무기태질소 함 량, 질소이용율, 수량 등을 조사하여 질소 화학비료 대체 가능성을 검토코자, 화학비료 3요소구, 혼합유기질비료 0, 100, 150% 시용구 등 5처리를 두어 2006년도에 시험을 수행한 결과는 다음과 같다. 혼합유기질비료 100% 시용구 토양 중 $NH_4-N$ 함량은 대조구에 비해 많았으며 표면수에서도 같은 경향이었다. 시험후 토양 중 Av. $P_2O_5$ 함량은 대조구에 비해 혼합유기질비료 100% 시용구에서 많았으나 Ex. K 함량은 적었다. 수도체 중 질소이용율은 혼합유기질비료 100% 시용구가 대조구에 비해 높아 질소 화학비료 대체 가능성이 있었다. 이앙 후 30일, 60일에서 경수는 혼합유기질비료 100% 시용구가 대조구 보다 많았다. 혼합유기질비료 중 질소 함량과 단백질 함량과는 정의 상관, 식미치와는 고도의 부의 상관, 완전립 비율과는 부의 상관이 있었다. 혼합유기질 비료 100% 시용구의 쌀 수량은 대조구 $4,892kg\;ha^{-1}$에 비해 4% 증가하였다. 벼 재배시 대조구의 쌀 수량과 대등한 혼합유기질비료의 시용량은 [질소 토양검정시비량 ${\div}$ 혼합유기질비료질소함량 $(g\;kg^{-1})/1,000{\times}0.93)/1,000$]으로 산출되었다.

• 한국토양비료학회지
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• 제31권4호
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• pp.350-358
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• 1998

시설재배 토양의 염류집적 방지를 위한 적정 시비량 추천방안을 구명하기 위하여 1997년도에 영동군, 보은군, 청원군, 및 청주시의 시설재배지로부터 염류농도가 다양한 18개 토양을 채취하여 폿트 시험으로 무비구와 시비구로 구분하여 토마토의 생산성과 비료효과를 조사하였다. 무비구의 토마토 건물중 및 질소, 인산, 칼륨 흡수량을 비옥도 요인으로 그리고 이들의 시비구와 무비구의 차이 값을 비료 전체효과 및 비료 질소, 인산, 칼륨효과로 고려하였다. 비옥도 및 비료효과 요인들은 토양 화학성들의 상호관계를 분석하여 시설재배지 토마토의 시비기준을 설정하기 위한 평가방법을 검토하였다. 비옥도 요인들에 대한 무기태 질소($NO_3-N$, $NH_4-N$) 함량의 표준화 편회귀계수는 247~1159의 범위를 보여 다른 화학성들의 0.02~4.02에 비하여 수백배의 높은 가중치를 보였다. 또한 무기태 질소($NO_3-N$, $NH_4-N$) 함량은 전기전도도에 대한 표준화 편회귀계수가 35.2-36.0으로 다른 화학성들의 1.0이하에 비하여 수십배의 높은 가중치를 나타냈다. 이러한 결과로부터 무기태 질소함량은 시설재배 토양의 비옥도와 전도도에 가장 크게 영향을 미치는 지표로 확인되었다. Cate-Nelson split 평가방법에 의한 토마토 최대 생산력과 비료효과 0가 되는 무기태 질소($NO_3-N+NH_4-N$) 함량은 $220mg\;kg^{-1}$으로 배추의 경우와 동일하게 추정되었다. 따라서 시설재배지 토양의 무기태 질소($NO_3-N$, $NH_4-N$) 함량이 $220mg\;kg^{-1}$ 이상인 토양은 무비 재배로 추천하고, 기준치 이하인 토양은 비료효과와 무기태질소 함량의 회귀식을 이용하여 시비기준의 추천이 가능하다.

• 한국유기농업학회지
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• 제19권spc호
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• pp.153-156
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• 2011

Supplying rate of nitrogen at HV was 172.8 kg $ha^{-1}$, HV/B was 64.3 kg $ha^{-1}$ and B was 38.6 kg $ha^{-1}$. The Rice yield was 7.05 ton $ha^{-1}$ when the nitrogen supply was the largest with HV and 5.42 ton $ha^{-1}$ was produced on HV/B. The chemical characteristics of soil have lower pH and exchangeable cations(Ca and Mg) at B, HV and HV/B, rather than at CF because green manure was applied at the former step. However, the physical characteristics of the soil and the porosity showed different tendency which was that it was better at the green manure crops than CF. Nitrogen nutrient balance was showed the most balanced at CF and field of application of green manure crops were required the appropriate management if future crops would be cultivated because nitrogen nutrient could be exhausted or accumulated.

• 한국토양비료학회지
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• 제44권5호
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• pp.745-751
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• 2011

In most agricultural soils, ammonium ($NH_4^+$) from fertilizer is quickly converted to nitrate ($NO_3^-$) by the process of nitrification which is crucial to the efficiency of N fertilizers and their impact on the environment. However, nitrification studies have been studied extensively in agricultural soils, not in a newly reclaimed tidal soil which show saline-sodic and high pH. Therefore, understanding the fate of nitrogen species transformed from urea introduced into reclaimed tidal soil is important for nutrient management and environmental quality. This paper reviewed studies regarding to transformation and fate of nitrogen sources such as urea under the circumstances of a reclaimed tidal soils located in a western coastal area.