• 농촌계획
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• 제11권4호
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• pp.67-74
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• 2005

The Doam watershed is located at alpine areas and the annual average precipitation, including snow accumulation, is significant higher than other areas. Thus, pollutant laden runoff and sediment discharge from the alpine agricultural fields are causing water quality degradation at the Doam watershed. To estimate soil erosion from the agricultural fields, the Universal Soil Loss Equation (USLE) has been widely used because of its simplicity to use. In the early spring at the Doam watershed, the stream flow increases because of snow melt, which results in erosion of loosened soil experiencing freezing and thaw during the winter. Also, extremely torrential rainfall, such as the typhoons 'RUSA' in 2002 and 'MAEMI' in 2003, caused significant amounts of soil erosion and sediment at the Doam watershed. However, the USLE model cannot simulate impacts on soil erosion of freezing and thaw of the soil. It cannot estimate sediment yield from a single torrential rainfall event. Also, it cannot simulate temporal changes in USLE input parameters. Thus, the Soil and Water Assessment Tool (SWAT) model was investigated for its applicability to estimate soil erosion at the Doam watershed, instead of the widely used USLE model. The SWAT hydrology and erosion/sediment components were validated after calibration of the hydrologic component. The R$^2$ and Nash-Sutcliffe coefficient values are higher enough, thus it is found the SWAT model can be efficiently used to simulate hydrology and sediment yield at the Doam watershed. The effects of snow melt on SWAT estimated stream flow and sediment were investigated using long-term precipitation and temperature data at the Doam watershed. It was found significant amount of flow and sediment in the spring are contributed by melting snow accumulated during the winter. Two typhoons in 2002 and 2003, MAEMI and RUSA, caused 33% and 22% of total sediment yields at the Doam watershed, respectively. Thus, it is recommended that the SWAT model, capable of simulating snow melt, sediment yield from a single storm event, and long-term weather data, needs to be used in estimating soil erosion at alpine agricultural areas to develop successful soil erosion management instead of the USLE.

• 한국유기농업학회지
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• 제21권1호
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• pp.69-78
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• 2013

비가림하우스에서 고랭지배추 유기재배 시 시용량 및 토양비옥도에 따른 시용질소의 이용률과 배추의 수량성을 검토하였다. 무비구에서의 구중은 사양토 토양에서 현저히 낮았으며, 비옥도가 낮은 사양토에 비해 비옥도가 높은 식양토에서 높았다. 시비량에 따른 구중의 변화는 비옥도가 높은 식양토에 비해 비옥도가 낮은 사양토에서 더 크게 나타났다. 질소이용률은 토양의 비옥도가 높고, 질소시비량이 많을수록 낮았다. 질소함량 1%의 사양토에서도 계분퇴비 2톤/10a과 표준시비량 수준의 천연무기질자재의 시용으로 질소함량 6%의 식양토의 약 90% 수준의 수량을 나타냈다. 질소, 인산, 및 칼리질 천연광물자원인 구아노, 인광석 및 황산가리고토 등은 친환경 자재로서 균형적 시비를 꾀하는 유기재배에서 널리 활용될 수 있을 것으로 보인다.

• 한국토양비료학회지
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• 제35권5호
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• pp.306-313
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• 2002

고랭지 여름배추 재배농가의 시비실태를 조사하여 시비개선 기초자료로 활용코져 1999~2001년에 58농가를 대상으로 청취조사한 결과, 3요소비료는 추천시비량에 비하여 질소 1.4배, 인산 2.4배, 칼리 2.0배를 시용하고 있었으며, 퇴비는 가축분퇴비 위주로 $9,920kg\;ha^{-1}$을 사용하고 있어 추천량보다도 감비하고 있는 반면, 석회질비료는 $2,160kg\;ha^{-1}$로 추천량에 접근하였다. 농가가 많이 사용하는 복합비료 비종은 기비로 11-10-10+3+0.3 (원예1호) > 11-6-6+4+13+17(쌀맛나) > 12-9-11+3+0.3(원예범용) 등의 순위이었고, 추비는 18-0-18+0.3(벼수비용) > 13-0-13+1+0.3(웃거름) > 18-0-15+0.3(NK마그) 등의 순위였다. 배추농가에서 퇴비는 계분퇴비 >돈분퇴비 >우분퇴비 >생계분순으로 전체 조사농가중 91.4%의 농가에서, 석회는 소석회 >생석회 >석회고토순으로 81%농가가 사용하였다. 고랭지배추 재배면적(10,206ha)을 적용한 총 소요량으로 볼 때 농가시비량의 절감 가능량은 성분량으로 4,347톤(질소 1,265톤, 인산 1,123톤, 칼리 1,959톤)으로 추정 할 수 있었다.

• 한국토양비료학회지
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• 제39권5호
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• pp.245-252
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• 2006

우리나라 토양의 분류체계를 보완하고 점토광물 조성과 분포를 파악하기 위하여 우리나라 390개 토양통 중 잔적 및 붕적토에서 유래된 26개 토양통을 대상으로 토양 층위별료 시료를 채취하여 집적층을(B층) 토양의 이화학적 특성, 토양 중 점토의 광물조성과 화학성분을 분석하였다. 잔적 및 붕적모재별로는 화강암과 화강편마암, 회장암에서 유래된 토양에서 kaolin과 quartz, 유문암, 3기층, 석영반암, 응회암에서 유래된 토양에서 quartz과 kaolin, 석회암, 혈암, 사암, 역암 등 퇴적암에서 유래된 토양에서 illite와 chlorite가 주요한 점토광물이었다. 토양통별 점토광물조성을 군집분석 (CA, cluster analysis)을 통하여 (1) illite, kaolin, vemiculite를 주광물로 하는 혼합점토광물군 (MIX), (2) kaolin을 주광물로 illite가 많은 kaolin군 (KA), (3) chlorite와 illite가 주광물인 chlorite군 (CH), (4) kaolin과 illite를 주광물로 smectite가 함유된 smectite군 (SM) 등 4개의 점토광물 조성군으로 구분하였다. 우리나라 토양의 대부분은 kaolin을 주광물로 하는 토양과 illite, kaolin, vemiculite가 함유된 토양이었으며, illite와 kaolin을 주광물로 하는 토양에서 CEC가 낮았고 vemiculite와 smectite가 함유된 점토에서 규반비가 높았다.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2003년도 춘계 학술발표논문집
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• pp.46-49
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• 2003

우리나라 고령지는 특이한 지형조건 때문에 집중강우가 많고 기상변동이 심하며 지역 간의 차이도 크다. 또한 고령지 밭토양은 경사지가 많아 유실이 심하여 대부분의 경작지는 토양환경이 불량한 상태에서 농업활동이 이루어진다. 이러한 고령지의 기상과 토양특성은 고랭지 농업생산성에서 볼 때 대단히 불리한 조건으로 작용하게 된다. 특히 토양의 수분상태는 작물의 수량에 직접적인 영향을 미칠 뿐만 아니라 병해의 발생에도 주요한 요인으로 작용하여 풍흉을 좌우하기도 한다.(중략)

• 한국토양비료학회지
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• 제47권4호
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• pp.284-289
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• 2014

Farmers in highlands in South Korea pile up 20 to 30 cm of saprolites, mostly granite- or granite-gneiss-weathered materials, on surface of arable lands every three to five years to compensate eroded soil and sometimes to discontinue soil-borne diseases. Immediate increases of infiltration and percolation rates are expected with coarse textured saprolites while soil drainage becomes poorer in a long-term. In this study, we analyzed mineralogical characteristics and micro-morphology of plow pan to investigate processes making impermeable layers. Soil samples were collected from plow pan, usually located at approximately 20 cm soil depth and at the lower part of piled saprolites, in arable lands in Hoenggye 5-ri, Daekwanryeong-myeon, Gangwon-do (N37.7, E128.7) in which saprolites were added 2, 4, and 8 years ago; saprolites were transported from similar areas. The saturated hydraulic conductivity decreased over time. Based on soil thin section pedography, quartz and feldspar accounted for a majority of minerals. The size of feldspar decreased and macropores became filled with clay or silt particles over time, which implies that macropores were packed with particles weathered from feldspar. The X-ray diffraction (XRD) analysis indicated that intensity of feldspar decreased over time and the reverse was true for kaolinite and illite, indicating that feldspar and mica weathering induced formation of kaolinite and illite. Conclusively, deteriorated drainage by formation of impermeable layers in farms with piled saprolites was caused by accumulation of clay minerals such as kaolinite and illite in macropores; illite and kaolinite can be formed by weathering of mica and feldspar, respectively.

• 한국물환경학회지
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• 제25권1호
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• pp.102-111
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• 2009

Turbid storm runoff from intensive highland agriculture area has emerged as the major problem of water quality deterioration in the upstream region of the Han River. High slope of the upland combined with high rate of fertilization and intensive plowing causes high rate of soil erosion, and subsequently high suspended sediment and phosphorus content in the runoff water. The variations of water quality during rain spells were surveyed for two years (2005 and 2006) in the Jawoon Stream that is one of hot spots of intensive horticulture discharging turbid storm runoff. SS and TP showed large increase according to the increase of flow rate, whereas TN and BOD showed less fluctuations. Mean EMCs of SS and TP measured for nine rain events were as high as $207mgSS{\cdot}L^{-1}$ and $0.27mgP{\cdot}L^{-1}$, respectively. The export coefficient of SS and TP per area of cultivated field were calculated as $11,912kgSS{\cdot}yr^{-1}{\cdot}km^{-2}$ and $785kgP{\cdot}yr^{-1}{\cdot}km^{-2}$, repectively, which are significantly higher than reports of other area. It can be concluded that SS and TP in the runoffs were high enough to impose major threat to aquatic habitats, and the highland agriculture should be the main target of water quality management or habitat conservation in the study area.

• 한국환경과학회지
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• 제32권11호
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• pp.777-788
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• 2023

Potato common scab disease is caused by pathogens belonging to Streptomyces spp. and results in a serious yield loss worldwide. Despite decades of research aimed at disease management, a definitive control method remains undiscovered. This study aims to explore the correlation between the C/N ratio and urea application with potato common scab pathogen dynamics and disease severity. We applied sawdust with a high C/N ratio and urea into the soil prior to potato cropping, both in pot and field experiments. Disease severity assessments and quantification of the TxtB gene were conducted at the harvest stage. Furthermore, culture experiments were performed to assess the direct impact of urea on the pathogen. Our findings revealed that higher disease severity was correlated with a high C/N ratio application and pathogenic gene quantity. Urea exhibited a direct influence on S. scabiei activity, reducing the disease severity in pot experiments. However, the effects of urea application on disease suppression in the conductive field were inconclusive. Although the results of urea application experiments displayed inconsistencies between pot and field trials, urea worked as the control to suppress S. scabiei activity. Further investigations are needed under various field conditions to confirm these findings.

• 한국토양비료학회지
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• 제43권5호
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• pp.616-623
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• 2010

고랭지 주요 채소에 대하여 일반 농가포장과 시험재배 포장을 대상으로 배추 49지점, 무 28지점, 양배추 16지점, 결구상추 8지점, 양파 20지점, 기타 대파, 적채 등 11 지점의 식물체 시료를 생육시기별로 채취하여 표고에 따른 질소, 인산 및 칼리 양분의 흡수양상을 조사하였다. 고랭지 여름배추의 무기성분 흡수량은 표고가 높을수록 증가하는 경향을 보였는데, ha당 수확기 흡수량은 N163~283 kg, $P_2O_5$ 42~71 kg, $K_2O$ 146~270 kg 수준을 보였다. 고랭지 무의 경우도 표고가 높은 600~800 m에서 증가되는 경향으로, ha당 수확기 흡수량을 보면 N153~159 kg, $P_2O_5$ 38~46 kg, $K_2O$ 151~185 kg 수준이었다. 기타 고랭지 양배추와 결구상추도 표고가 높을수록 양분흡수량이 증가하는 경향을 보였는데, 양배추의 ha당 수확기 흡수량은 N 280~348 kg, $P_2O_5$ 34~87 kg, $K_2O$ 209~290 kg이었으며, 고랭지 결구상추의 경우 ha당 N 66~93 kg, $P_2O_5$ 21~26 kg, $K_2O$ 117~126 kg 수준을 보였다. 고랭지 양파의 ha당 무기성분 흡수량은 N 226~313 kg, $P_2O_5$ 136~140 kg, $K_2O$ 234~252 kg 수준으로 표고에 따른 일정 경향은 없었다. 기타 지금까지 시비추천 기준이 설정되어 있지 않은 대파, 양미나리, 녹색꽃양배추, 적색양배추 등 소면적 재배작물의 양분흡수량을 조사하여 기존 양분흡수량 보정계수 (시비기준이 설정된 유사작물의 시비추천식 적용) 활용으로 시비추천기준의 설정이 가능하였다.

• Journal of Plant Biotechnology
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• 제36권2호
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• pp.170-173
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• 2009

Leaf and petiole explants of Pulsatilla koreana NAKAI were cultured on MS medium supplemented with various concentrations of zeatin, kinetin or BAP combined with 0.05 mg/L IAA. After 6 weeks of culture, effects of cytokinin on adventitious shoot formation from explants were investigated. The highest frequency of shoot formation was obtained when petiole explants were cultured on medium with 0.5 mg/L zeatin and 0.05 mg/L IAA. Regenerated shoot were transferred on to root induction medium. The best root formation was observed at 1/2 MS medium with 1.5 mg/L NAA. Rooted plantlets were transplanted to a mixture of perlit and soil (1:3), where they were successfully acclimatized.