• 한국토양비료학회지
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• 제46권3호
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• pp.216-222
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• 2013

Fertilizer management has the potential to promote the storage of carbon and nitrogen in agricultural soils and thus may contribute to crop sustainability and mitigation of global warming. In this study, the effects of fertilizer practices [no fertilizer (Control), chemical fertilizer (NPK), Compost, and chemical fertilizer plus compost] on soil total carbon (TC) and total nitrogen (TN) contents in inner soil profiles of paddy soil at 0-60 cm depth were examined by using long-term field experimental site at $42^{nd}$ years after installation. TC and TN concentrations of the treatments which included N input (NPK, Compost, NPK+Compost) in plow layer (0-15 cm) ranged from 19.0 to 26.4 g $kg^{-1}$ and 2.15 to 2.53 g $kg^{-1}$, respectively. Compared with control treatment, SOC (soil organic C) and TN concentrations were increased by 24.1 and 31.0%, 57.6 and 49.7%, and 72.2 and 54.5% for NPK, Compost, and NPK+Compost, respectively. However, long term fertilization significantly influenced TC concentration and pools to 30 cm depth. TC and TN pools for NPK, Compost, NPK+Compost in 0-30 cm depth ranged from 44.8 to 56.8 Mg $ha^{-1}$ and 5.78 to 6.49 Mg $ha^{-1}$, respectively. TC and TN pools were greater by 10.5 and 21.4%, 30.3 and 29.6%, and 39.9 and 36.3% in N input treatments (NPK, Compost, NPK+Compost) than in control treatment. These resulted from the formation and stability of aggregate in paddy soil with continuous mono rice cultivation. Therefore, fertilization practice could contribute to the storage of C and N in paddy soil, especially, organic amendments with chemical fertilizers may be alternative practices to sequester carbon and nitrogen in agricultural soil.

• 한국토양비료학회지
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• 제50권5호
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• pp.369-382
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• 2017

Accurate and optimal water supply to cereal crop is critical in growing stalks and producing maximum yields. Recently, upland crops are cultivated in paddy field soils to reduce overproduced rice in Korea. In order to increase productivity of cereal crops in paddy fields which have poor percolation and drainage properties, it is necessary to fully understand crop response to excessive soil water condition and management of soil drainage system in paddy field. The objectives of this study were to investigate effects of excessive soil water to sesame growth and to quantify stress response using groundwater levels. Two cultivars of sesame were selected to investigate; Gunbak and Areum. These sesames were planted in paddy fields located in Miryang, Gyeongnam with different soil drainage levels and drainage systems. The experiment site was divided into two plots by drainage class; very poorly and somewhat poorly drained. Two different drainage systems were applied to alleviate excessive soil water in each plot: open ditch and pipe drainage system. Soil water contents and groundwater levels were measured every hour during growing season. Pipe drainage system was significantly effective to alleviate wet injury for sesame in paddy fields. Pipe drainage system decreased average soil moisture content and groundwater level during sesame cultivation. This resulted in greater yield and lignan contetns in sesame seeds than ones from open ditch system. Comparison between two cultivars, Gunbak had greater decrease in growth and yield by excessive soil water and high groundwater level than Areum. Seed components (lignan) showed decrease in seeds as soil water increased. When soil moisture content was greater than 40%, lignan content tended to decrease than ones from less soil moisture content. Based on these results, pipe drainage system would be more effective to reduce wet injury to sesame and increase lignan component in paddy field cultivation.

• Journal of Biosystems Engineering
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• 제36권1호
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• pp.33-39
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• 2011

An optical sensing approach based on diffuse reflectance has shown potential for rapid and reliable on-site estimation of soil properties. Important sensing ranges and the resulting regression models useful for soil property estimation have been reported. In this study, a similar approach was applied to investigate the potential of reflectance sensing in estimating soil properties for Korean paddy fields. Soil cores up to a 65-cm depth were collected from 42 paddy fields representing 14 distinct soil series that account for 74% of the total Korean paddy field area. These were analyzed in the laboratory for several important physical and chemical properties. Using air-dried, sieved soil samples, reflectance data were obtained from 350 to 2500 nm on a 3 nm sampling interval with a laboratory spectrometer. Calibrations were developed using partial least squares (PLS) regression, and wavelength bands important for estimating the measured soil properties were identified. PLS regression provided good estimations of Mg ($R^2$ = 0.80), Ca ($R^2$ = 0.77), and total C ($R^2$ = 0.92); fair estimations of pH, EC, $P_2O_5$, K, Na, sand, silt, and clay ($R^2$ = 0.59 to 0.72); and poor estimation of total N. Many wavelengths selected for estimation of the soil properties were identical or similar for multiple soil properties. More important wavelengths were selected in the visible-short NIR range (350-1000 nm) and the long NIR range (1800-2500 nm) than in the intermediate NIR range (1000-1800 nm). These results will be useful for design and application of in-situ close range sensors for paddy field soil properties.

• 한국작물학회지
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• 제50권6호
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• pp.387-393
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• 2005

2002년부터 2004년까지 수원의 작물과학원 논포장을 년차간 순차적으로 밭으로 전환하고 또 밭상태에서 우분을 누적투 입하면서 호밀과 옥수수의 윤작을 통하여 질소와 관련된 토양 특성, 작물의 건물수량 및 질소흡수량을 조사하였는데, 주요 결과는 다음과 같다. 논의 밭전환 1년차에는 밭사료작물, 특히 답리작 호밀의 생육과 수량이 현저히 감소하였으며, 그에 따라 우분시용에 의한 무기태질소 등 양분의 이용효율도 현저히 감소하였다. 그러나 전환년차의 증가와 함께 밭사료작물의 수량과 질소흡수량이 증가하였는데, 특히 밭상태에서 전환3년차까지 우분의 누적투입은 토양에의 무기태 질소공급과 더불어 옥수수의 수량, 질소흡수량 및 우분질소 이용률을 계속적으로 증가시켰다. 그 증가는 전환년차 증가에 따른 논토양 자체의 질소공급보다는 주로 우분시용에 의한 토양물리성 개선, 토양탄소 및 무기화 가능한 지력질소(가급태질소) 증가 등 지력증진에 크게 기인하였다. 따라서 전환밭에서 정상적인 밭사료작물의 수량을 얻기 위해서는 전환2년 이상의 기간이 필요하였으며, 이때 우분의 투입은 토양에 무기태질소 공급뿐만아니라 토양유기물 등 지력증진에도 효과적이었으며, 또한 그것이 누적적으로 투입될 때 그 효과가 증가되는 것으로 나타났다.

• 한국습지학회지
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• 제25권4호
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• pp.237-247
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• 2023

논은 다양한 생태계 서비스를 제공할 뿐만 아니라 생물다양성 보전에 중요한 서식지이며, 최근 생태학적 가치와 중요성이 점점 강조되고 있다. 따라서 본 연구는 영농 방식이 서로 다른 관행 논(Conventional Paddy field, CP)과 유기 재배 논(Organic Paddy field, OP)을 대상으로 토양 종자은행의 특성을 파악하고 토양 환경 요인과의 상관관계를 분석하였다. 연구결과 관행 논의 식생은 단순하여 종자은행의 식물 다양성이 낮은 반면에, 유기 논의 식생은 상대적으로 다양하여 종자은행의 식물 다양성이 높게 나타났다. 또한 토양 환경 특성도 유기 논 (K, Ca, Mg, Na, Fe, Mn, B↓) 과 관행 논(K, Ca, Mg, Na, Fe, Mn, B↑)의 명확한 차이를 보였다. 이러한 결과는 벼 재배 방식에 대한 영농 활동의 차이가 식생과 토양 종자은행의 구조와 다양성에 영향을 주었고 또한 토양 환경 요인에도 직간접적으로 영향을 준 것으로 판단된다. 본 연구결과는 농업생태계 생물다양성 보전과 생태계 복원 그리고 생태적 가치를 평가하기 위한 기초자료로 활용될 수 있다.

• 한국자원식물학회지
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• 제20권3호
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• pp.258-262
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• 2007

The study was conducted to evaluate the performance of the popular isoflavone-rich soybean 'agakong' in upland and in drained-paddy fields. Analysis revealed no significant variation in terms of plant height, number of seeds per pod, number of nodes, and 100-seed weight between the two cropping system. Number of pods was significantly higher in paddy field(234.2kg 10a$^{-1}$) compared to those harvested in the upland field, which was later manifested on the yield where paddy soybeans obtained 278.1kg 10a$^{-1}$ whereas upland only obtained 179.3kg 10a$^{-1}$. This observed difference in yield was attributed to the observed higher amount of N in the paddy soil (0.907%) as compared to the upland soil (0.458%). In terms of nutritional content, protein and phytic acid contents were the only parameters that showed significant differences while oil, sugar, reducing power and fatty acids were all comparable in paddy and filed condition. Protein content was higher in upland soil (47.4%) than that of the paddy (44.9%) soil. On the opposite, phytic acid was higher in paddy (2.90%) than in upland (1.09%). This study showed that the yield of soybean is generally a factor of soil N, drained-paddy field production of soybean is comparable to upland-filed production with the benefit of increasing phytic acid content while maintaining its nutritional value.

• 한국토양비료학회지
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• 제40권4호
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• pp.326-329
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• 2007

Quantifying soil organic carbon (SOC) has long been considered to improve our understanding of soil productivity, soil carbon dynamics, and soil quality. And also SOC could contribute as a major soil management factor for prescribing fertilizers and controlling of soil erosion and runoff. Reducing tillage intensity has been recommended to sequester SOC into soil. On the other hand, determination of traditional SOC could barely identify the tillage practices effect. Physical soil fractionation has been reported to improve interpretation of soil tillage practices impact on SOC dynamics. However, most of these researches were focused onupland soils and few researches were conducted on paddy soils. Therefore, the objective of this research was to evaluate paddy soil tillage impact on SOC by physical soil fractionation. Soils were sampled in conventional-tillage (CT), partial-tillage (PT), no-tillage (NT), and shallow-tillage (ST)plots at the National Institute of Crop Science research farm. Samples were obtained at the three sampling depth with 7.5-cm increment from the surface and were sieved with 0.25- and 0.053-mm screen. Soil organic carbon was determined by wet combustion method. Significant difference of SOC contentwas found among sampling soil depth and soil particle size. SOC content tended to increase at the ST plot with increasing size of soil particle fraction. We conclude that quantifying soil organic carbon by physical soil particle fractionation could improve understanding of SOC dynamics by soil tillage practices.

• 한국환경농학회지
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• 제30권4호
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• pp.367-376
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• 2011

논 토양의 미생물 생태 다양성을 조사하기 위한 효과적인 방법으로 qRT-PCR을 적용하고자 본 연구를 수행하였다. 논 토양 미생물의 gDNA를 분리하기 위하여 Mo Bio kit를 사용한 효과적이고 안정적인 gDNA 분리 방법을 확립하였다. 논 토양 미생물 다양성을 qRT-PCR로 검출하기 위하여 bacteria를 세분한 ${\alpha}$-Proteobacteria, ${\beta}$-Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes 다섯 가지 문과 전체 bacteria, 전체 fungi를 구분할 수 있는 특이 primer set을 선정하여 다양한 조건의 시험을 통하여 최종 조건을 확립하였으며 재현성 실험을 통하여 방법의 유의성을 검증하였다.

• 대한환경공학회지
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• 제38권9호
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• pp.504-512
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• 2016

본 연구에서는 토양 및 수질 특성 모니터링을 통한 유기논과 관행논의 환경 영향을 조사하였다. 용인과 안성 지역의 유기논과 관행논에서 표층(0~15 cm) 및 심층(15~30 cm) 토양과 수질 시료를 채취 및 분석하였다. 집단 간의 유의성의 차이는 던컨의 다중검정으로 판별하였다. 실험 결과 T-P 농도는 표층 및 심층 토양 모두에서 안성 지역이 용인 지역보다 높게 나타났다. 안성 논토양에서 유기논과 관행논의 T-P 농도의 차이는 유의미한 차이를 보였지만, 용인에서는 나타나지 않았다. 용인과 안성 지역 모두에서 유기논 토양의 T-N 농도는 관행논 보다 낮게 나타났다. 안성 유기논의 심층 토양의 수분함량은 다른 논에 비하여 현저한 차이가 나타났으며, 이는 silt-clay 함량 결과와 일치한다. 관행논 물의 pH와 EC는 유기논에 비하여 높게 나타났다. 안성 지역에서 관행논의 COD, T-P, 그리고 $PO_4-P$가 유기논에 비하여 높게 나타났다. 회귀분석 결과 T-N을 제외하고 토양 특성과 수질 결과 간에 상관성이 없었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.91.2-92
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• 2003

In order to elucidate influence of nutritional status on rice brown spot caused by Cochliobolus miyabeanus, rice cultivation soils and rice straws were collected from paddy fields where ice brown spot occurred severely, moderately, a little and none respectively. Rice plant materials were analyzed to measure inorganic nutrients in rice straws and rice seeds. Analysis of chemical properties of rice paddy soil showed that EC and contents of available phosphate, cation and silicic acid in soil with severe infections were lower than those in healthy soil. This result suggests that amount and holding capacity of nutrient contents in soils collected from paddy field with infection of C. miyabeanus are relatively low compared to those in soils collected from healthy paddy field. Analysis of inorganic nutrients in rice straws showed that amount of macronutrient elements such as silicic acids, available phosphate and total nitrogen, and micronutrients such as copper, iron and zinc in rice straws from paddy field with infection were lower than those in healthy soil. Especially amount of iron and silicic acid were very low in rice straws from paddy field soils with infection Amount of inorganic nutrients such as iron and zinc in rice seeds was the same trend as those of rice straws. These results showed that one of major factors affecting rice brown spot was amount of nutrient contents in soil and rice straw.