• 한국작물학회지
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• 제45권5호
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• pp.294-299
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• 2000

Hairy vetch (Vicia villosa Roth) winter annual is very effective on reducing chemical nitrogen fertilizer for subsequent com by fixed organic green manure nitrogen fixed during hairy vetch growth. In this experiment, hairy vetch produced above-ground dry matter of 5 ton/ha, nitrogen yield 200 kgN/ha, at com planting on the average during 1997 and 1998. Changes in com yield and nitrogen uptake for two years were investigated after application of nitrogen fertilizer 0, 60, 120, 180, 240 kgN/ha on plot of winter fallow and hairy vetch green manure, respectively. Nitrogen status such as ear-leaf N%, SPAD value at silk and dough stage, and com yield decreased in proportion to reduction of nitrogen fertilizer at winter fallow, but nitrogen status and yield of com were not different among nitrogen fertilizer rate at hairy vetch green manure. Com yield (total dry matter) at 0 kgN/ha plot of hairy vetch was 22, 20 ton/ha in 1997, 1998, respectively and com could produce more dry matter 9, 13 ton/ha by hairy vetch green manure compared with winter fallow under the condition of no nitrogen fertilizer in 1997, 1998, respectively. Com yield (total dry matter) at 60kgN/ha of hairy vetch green manure was higher than that of high N fertilizer rate such as 180, 240 kgN/ha of winter fallow. Nitrogen uptake of com at plot of hairy vetch-no nitrogen fertilizer slightly decreased than at plot of hairy vetch - nitrogen fertilizer, but com absorbed more nitrogen of 141, 159 kgN/ha by hairy vetch green manure compared with winter fallow under no nitrogen fertilizer condition in 1997, 1998, respectively. Nitrogen fertilizer reduction for com by hairy vetch green manure was 149, 161kgN/ha in 1997, 1998, respectively. Still more, com could absorb more soil nitrogen by nitrogen fertilizer 60kgN/ha of hairy vetch green manure than by high nitrogen fertilizer such as 180, 240 kgN/ha at winter fallow. It is concluded that nitrogen fertilizer for corn could be reduced by winter cultivation and soil incorporation of hairy vetch at com planting.

• 한국토양비료학회지
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• 제46권3호
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• pp.187-192
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• 2013

This study was carried out to investigate the incorporation effect of green manure crops (GMC) such as the hairy vetch on improvement of soil environment in reclaimed land during silage corn cultivation over the past two years. Plots consisted of conventional fertilization (CF) and incorporation of GMC were divided by addition rate of nitrogen fertilizer (100 kg $ha^{-1}$) with 30 - 100% of non nitrogen fertilization (NNF). Soil physico-chemical properties and growth and yield potential of silage corn were examined. The tested soils showed strong alkali and saline properties with low contents of organic matter and available phosphate while contents of exchangeable sodium and magnesium were high. Soil salinity increased during cultivation of summer crop. However, corn was not affected by salt content. The fresh weight of GMC at incorporation time was 18,345 kg $ha^{-1}$. Content of total nitrogen was 3.09% and the C/N ratio was 12.8 at incorporation time. Fresh and dry matter yield of silage corn were higher in the order of N30% reduction, CF, N50% reduction, N70% reduction, N100% reduction and NNF. Fresh and dry matter yield potential of silage corn for N30% reduction were comparable to those of CF. Bulk density of the soil decreased with incorporation of GMC, while porosity was increased. The soil pH decreased while content of exchangeable calcium, available phosphate, and organic matter increased. Also contents of exchangeable sodium and potassium decreased with incorporation of GMC. The data indicate that incorporation of hairy vetch can improve soil physical and chemical properties and reduce nitrogen fertilizer application especially for alkali saline reclaimed soil such as Saemangeum reclaimed land.

• 한국환경농학회지
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• 제42권4호
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• pp.418-426
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• 2023

This study focused on nitrous oxide, a major greenhouse gas produced in agricultural settings through bacterial nitrogen oxidation in aerobic soil. Nitrogen fertilizer in farmland is identified as a primary source of nitrous oxide. The importance of reducing excess nitrogen in soil to mitigate nitrous oxide production is well-known. The study investigated the use of liquefied pig manure as an alternative to urea fertilizer in conventional agriculture. Results showed a more than two-fold reduction in nitrous oxide emissions in pepper cultivation areas with liquefied pig manure compared to that with urea fertilizer. The population of Nitrosospira, a nitrous oxide-producing bacterium, decreased by over 10% with liquefied pig manure. Additionally, nirK and nosZ, which are related to the denitrification process, significantly increased in the urea fertilizer group, whereas levels in the liquefied pig manure group resembled those with no nitrogen treatment. In conclusion, the experiment confirmed that liquefied pig manure can serve as an eco-friendly nitrogen fertilizer, significantly reducing nitrous oxide production, a major contributor to the atmospheric greenhouse effect.

• 한국유기농업학회지
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• 제26권4호
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• pp.619-628
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• 2018

This study analyze the economic effect of chemical fertilizer. We used the input and output data, and the analysis variables include production output nitrogen, phosphoric acid, potassium, seeds, and labor. The main results are as follows. First, for spring potatoes, potassium increases to a certain level of output, but over a certain stage, the output decreases as the input increases. Optimal use of potassium in the calculation of spring potatoes can achieve the effect of reducing input costs and increasing output simultaneously. Second, radish In autumn, nitrogen increases to a certain level, but over a certain stage it represents a reverse U-shaped relationship in which output decreases as input increases. This means that reducing the amount of fertilizer input increases the output. This means that soil-related agricultural big data can contribute to the management of nutrients and greenhouse gas reduction in agricultural land.

• 한국토양비료학회지
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• 제49권1호
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• pp.7-11
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• 2016

Winter crops have been recognized as an alternative to soil management for fertility and crop productivity in paddy soil. Recently, rape has been produced at winter season and there is little research results on reduction of N fertilizer by adding rape residues for rice cultivation. In this study, we investigated the productivity and quality of rice by applying with 0, 27, 63, $90kg\;ha^{-1}$ of N fertilizer after input of rape residues into soil for two years. The highest yield of rice was average $4.68Mg\;ha^{-1}$ at the treatment applied with the $90kg\;N\;ha^{-1}$ with rape residue. It was reduced to N rate from 31.6 to $43.2kg\;N\;ha^{-1}$ in comparison to $4.53Mg\;ha^{-1}$ of maximum yield in treatment added $90kg\;N\;ha^{-1}$ with rape. Amylose content in rice was similar among treatments with/without rape residue, but protein content was lower in treatment with rape residue than in those without rape residue. In conclusion, input of rape residue in rice cultivation could be alternative to reduction of N fertilization and improvement of quality by adjusting rice productivity in paddy soil under cropping system.

• 한국환경농학회지
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• 제41권4호
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• pp.230-235
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• 2022

BACKGROUND: Ammonia gas emitted from nitrogen fertilizers applied in agricultural land is an environmental pollutant that catalyzes the formation of fine particulate matter (PM2.5). A significant portion (12-18%) of nitrogen fertilizer input for crop cultivation is emitted to the atmosphere as ammonia gas, a loss form of nitrogen fertilizer in agricultural land. The widely practiced method for fertilizer use in agricultural fields involves spraying the fertilizers on the surface of farmlands and mixing those with the soils through such means as rotary work. To test the potential reduction of ammonia emission by nitrogen fertilizers from the soil surface, we have added N, P, and K at 2 g each to the glass greenhouse soil, and the ammonia emission was analyzed. METHODS AND RESULTS: The treatment consisted of non-fertilization, surface spray (conventional fertilization), and soil depth spray at 10, 15, 20, 25, and 30 cm. Ammonia was collected using a self-manufactured vertical wind tunnel chamber, and it was quantified by the indophenol-blue method. As a result of analyzing ammonia emission after fertilizer treatments by soil depth, ammonia was emitted by the surface spray treatment immediately after spraying the fertilizer in the paddy soil, with no ammonia emission occurring at a soil depth of 10 cm to 30 cm. In the upland soil, ammonia was emitted by the surface spray treatment after 2 days of treatment, and there was no ammonia emission at a soil depth of 15 cm to 30 cm. Lettuce and Chinese cabbage treated with fertilizer at depths of 20 cm and 30 cm showed increases of fresh weight and nutrient and potassium contents. CONCLUSION(S): In conclusion, rather than the current fertilization method of spraying and mixing the fertilizers on the soil surface, deep placement of the nitrogen fertilizer in the soil at 10 cm or more in paddy fields and 15 cm or more in upland fields was considered as a better fertilization method to reduce ammonia emission.

• 한국토양비료학회지
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• 제38권4호
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• pp.194-201
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• 2005

본 연구에서는 규산질 비료 시용을 통한 질소의 흡수 이용율을 증진하고 이용율 증진에 따른 질소 시비량 저감방안을 모색하였다. 경남 하동 소재의 전형적 논토양(가천통)에서 규산 처리수준에 따른 질소 이용을 증진효과를 평가하기 위해 무처리, 유효규산 $130mg\;kg^{-1}$ 조절 처리, 조절량의 2배 처리와 같은 세 수준의 규산처리를 기본처리구로 설정하였다. 각 규산 처리조건에서 0, 110, $165kg\;ha^{-1}$의 세 수준으로 질소를 처리하여 벼 재배과정 중 수량반응특성 및 양분흡수특성을 조사하였다. 동일수준의 질소 처리조건에서 정조 수량과 질소이용률은 규산질 비료 처리수준이 증가함에 따라 유의적으로 크게 증가되었다. 규산질 비료를 처리하지 않았을 때 질소 $154kg\;ha^{-1}$ 수준에서 최고 정조 수량 획득이 가능하였다. 규산질 비료를 추천량인 $130mg\;kg^{-1}$과 추천량의 배 량 처리시 벼의 생육증가에 따른 질소 흡수 이용율 증가로 약 76과 $52kg\;ha^{-1}$의 질소처리조건에서 규산 무처리 때 얻을 수 있는 최고 정조 수량의 획득이 가능한 것으로 분석되었다. 결과적으로 규산질 비료처리 없이 얻을 수 있는 최고 정조수량을 얻기 위해 필요한 질소 시비량인 $154kg\;ha^{-1}$을 규산질 비료 추천량과 추천량의 배량 처리로 인해 약 76과 $102kg\;ha^{-1}$의 질소 시비량 저감이 각각 가능할 것으로 분석되었다. 그리고 규산질 비료시용으로 토양 pH가 다소 개선되었으며, 토양 내 유효 인산 및 규산 함량이 크게 증가하여 토양의 비옥도 증진에 효과가 있는 것으로 조사되었다.

• 한국농공학회논문집
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• 제53권4호
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• pp.59-65
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• 2011

The purpose of this study was to analyze the water quality change when wastewater applied to study paddy fields. CREAMS-PADDY (Chemical, Runoff and Erosion from Agricultural Management System) model was used to estimate the field-scale water quality. Simulated results were compared with observed data monitored from Byeongjeom study paddy fields which is located near the Suwon sewage treatment plant in Gyeonggi-do. Significance analysis was performed for the three different irrigation water quality level and five fertilizer reduction scenarios using LSD (Least Significant Difference) and DMRT (Duncan's Multiple Range Test). Total nitrogen was found to be significant for both irrigation water quality level and fertilizer reduction while total phosphorus was not. Annual drainage load for total nitrogen was reduced by 66~92 % compared to irrigation load when treated wastewater irrigated to study paddy fields from 2002 to 2007. Total phosphorus was reduced by 70~86 %.

• 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.

• 한국초지조사료학회지
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• 제16권2호
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• pp.113-120
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• 1996

The experiment was carried out to investigate the effects of phosphate fertilizer level on growth, crude protein content and nitrogen fixation ability of alfalfa(Medicugo sariva L.) at sowing year. The experimental field was conducted using a randomized block design with three replications according to the phosphate application level (200 and 400kfia) in farm of Kongju National University. Research samples were collected at intervals of 7 days from October 7 to December 9 and nitrogen fixation activity of nodule was measured by using the acetylene reduction method (Hardy et al. 1968). The results obtained are summarized as follows : 1. Number of branches, root length and dry matter weight at phosphate fertilizer level of 400kg in sowing year were more increase than those of 200kfia. The number of nodules was not significantly difference between phosphate fertilizer level, because of low temperature to be enough to nodulation of alfalfa. 2. The crude protein content of leaf, stem and root were not significantly affected by the phosphate fertilizer level. but that of leaf was increased at 400kgha on 72 days after sowing. The crude protein content of each part according to growing stages was increased at 44 days and 72 days after sowing. 3. The dry weight of root was not significantly difference between phosphate fertilizer level from 30 days to 51 days after sowing, but that was increased at phosphate fertilizer level of 400kgha from 51 days afier sowing. 4. The amount of ethylene in the samples taken 2 hours and calculated amount of nitrogen fixation were increased at phosphate fertilizer level of 400kfia from 30 days to 65 days after sowing. but there was vice versa from 58 days after sowing.