• 한국토양비료학회지
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• 제42권3호
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• pp.145-151
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• 2009

논에서 전환된 포도원(전환포도원)의 전환 후 년수 및 토양특성별 물리적 특성변화 양상을 구명하여 전환지 생산성 향상을 위한 합리적 토양 관리대책을 제시코자 전환지가 많은 경북 김천, 영천지역을 중심으로 포도원과 인근 벼 재배지 50개 지점을 조사 분석한 결과 전환포도원의 이랑 높이는 토성이 세립질이고 배수가 불량할수록 높았고, 토양단면 내 반문의 출현깊이(Ap층 두께)는 조립질 토양에서 깊은 경향이었음. 전환지는 인근 유사토양 벼 재배지 작토층 토색의 경우 색상이 밝아지는 경향을 보여 회색도가 벼 재배지의 경우 20인데 비해 전환지는 5로 감소했고, 이 경향은 토양 배수조건이 양호한 토양에서 현저하였음. 전환여부에 따른 투기도 차이는 토심10cm 이하에서 현저했고 토심 30cm 이하에서는 뚜렷한 차이가 없었고 전환지에서 투기도에 미치는 토양특성의 영향은 세립질의 경우 이랑의 높이가, 조립질은 배수등급이었다. 전환포도원의 물리성은 전환 후 년수가 경과함에 따라 공극율과 내수성입단이 증가하는 경향이었고, 원추관입저항의 경우 휴립한 부위는 $5kg/cm^2$ 이하인 반면, 그 이하의 부위는 $10kg/cm^2$ 이상을 보였음. 이상의 결과로 볼 때 전환포도원의 토양특성은 세립질보다 조립질이 쉽게 변하는 경향이었고, 배수불량인 세립질토양에서는 고휴재배 등 적절한 표토관리가 요구되었다.

• 한국토양비료학회지
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• 제47권6호
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• pp.500-505
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• 2014

In recent years, organic ginseng cultivation has increased because customers prefer organic ginseng products due to the morphological quality as well as the safety such as the residuals of chemically-synthesized pesticides. Therefore, some of paddy and upland fields were converted into organic ginseng fields. Soil chemical properties, soil microflora, and soil-inhabiting animals were investigated in paddy-converted and upland organic ginseng fields in Sangju city, Korea. There was few difference in the soil chemical properties, and the soil nutrient concentrations, such as nitrate-N, Av. $P_2O_5$ between the two field types, and exchangeable cations such as K and Ca were within the ranges which are recommended by the standard ginseng-farming manual. Changes in microflora were also assessed by analyzing phospholipid fatty acid composition. Overall, indicators of microbial groups were greater in the upland field than in the paddy-converted soil, but they were not significantly different. In addition, there was no significant change in the abundance of nematodes, collembolans, and mites between the two field types probably because of the high variation within the field types. In this study, it was suggested that soil chemical and biological properties for organic ginseng cultivation were greatly influenced by the variation of topography and soil management practices rather than field types. Further study may be needed to investigate the influence of these factors on soil chemical and biological properties in organic ginseng soils.

• 한국토양비료학회지
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• 제27권2호
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• pp.98-104
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• 1994

1989~'93년(年)까지 5년(年)동안 답전수환시(畓田輸換時) 작부체계(作付體系)에 따른 토양(土壤) 층위별(層位別) 양분분포(養分分布)와 양분수지(養分收支)를 검토(檢討)한 결과(結果)는 아래와 같았다. 1. 질산태질소(窒酸態室素), 치환성가리(置換性加里) 및 유효인산(有效燐酸) 함량(含量)과 EC는 표층(表層) 0~20cm에서 약간 높았을뿐 토층하부(土層下部)로 이동집적(移動集積)이 적었고, 작부체계(作付體系)에 따른 표토중(表土中) 함량은 전이환(田轉換) 감자-배추>2년 수환(輸換) 감자-배추>전전환(田轉換) 대두(大豆)>수도연작구(水稻連作區) 순(順)으로 높아 처리별(處理別) 시비량을 반영(反影)하였다. 2. 치환성(置換性) 석회(石灰)와 고토(苦土) 함량 및 pH는 심토(深土)로 갈수록 높아졌고, 이러한 경향은 특히, 수도연작구(水稻連作區)에서 현저(顯著)하였다. 작부체계(作付體系)에 따라서는 전(全) 토층(土層)에서 전전환(田轉換) 대두(大豆)>전전환(田轉換) 감자배추>2년(年) 윤환(輪換) 감자-배추>수도연작구(水稻連作區) 순(順)이었고 처리별 식물체 흡수량(吸收量) 차이가 크게 영향하였다. 3. 전전환(田轉換) 감자-배추구(區)에서 질소(窒素), 인산(燐酸), 가리(加里)의 양분수지(養分收支)는 투입량(投入量)보다 탈취량(奪取量)(흡수량)이 각각(各各) 21.5, 26.8, 9.2kg/10a 많았으나 투입량(投入量)중 화학비료량(化學肥料量)은 질소(室素)와 가리(加里)의 경우 탈취량(奪取量)에 비해 적었던 반면 인산(燐酸)은 많았다. 4. 전전환(田轉換) 대두구(大豆區)의 양분수지(養分收支)는 질소(窒素), 인산(燐酸), 가리(加里) 각각(各各) -12.8, 4.1, -1.0kg/10a로 질소(窒素)와 가리(加里)의 투입량(投入量)이 탈취량(奪取量)보다 적었으나 질소(窒素)는 근류균(根瘤菌)의 질소고정(窒素固定)으로 결핍되지 않았던 반면 가리(加里)는 생육중기(生育中期)에 결핍증상(缺乏症狀)을 나타내었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.315-315
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• 2017

In Japan, more than 80 % of soybean growing area is converted fields and excess water is one of the major problems in soybean production. For example, recent study (Yoshifuji et al., 2016) suggested that in the fields of shallow groundwater level (GWL) (< 1m depth), rising GWL even in a short period (e.g. 1 day) causes inhibition of soybean growth. Thus it becomes more and more important to predict GWL and soil moisture in detail. In addition to conventional surface drainage and underdrain, FOEAS (Farm Oriented Enhancing Aquatic System), which is expected to control GWL in fields adequately, has been developed recently. In this study we attempted to predict GWL and soil moisture condition at the converted field with FOEAS in Biwa lake reclamation area, Shiga prefecture, near the center of the main island of Japan. Two dimensional HYDRUS model (Simuinek et al., 1999) based on common Richards' equation, was used for the calculation of soil water movement. The calculation domain was considered to be 10 and 5 meter in horizontal and vertical direction, respectively, with two layers, i.e. 20cm-thick of plowed layer and underlying subsoil layer. The center of main underdrain (10 cm in diameter) was assumed to be 5 meter from the both ends of the domain and 10-60cm depth from the surface in accordance with the field experiment. The hydraulic parameters of the soil was estimated with the digital soil map in "Soil information web viewer" and Agricultural soil-profile physical properties database, Japan (SolphyJ) (Kato and Nishimura, 2016). Hourly rainfall depth and daily potential evapo-transpiration rate data were given as the upper boundary condition (B.C.). For the bottom B.C., constant upward flux, which meant the inflow flux to the field from outside, was given. Seepage face condition was employed for the surrounding of the underdrain. Initial condition was employed as GWL=60cm. Then we compared the simulated and observed results of volumetric water content at depth of 15cm and GWL. While the model described the variation of GWL well, it tended to overestimate the soil moisture through the growing period. Judging from the field condition, and observed data of soil moisture and GWL, consideration of soil structure (e.g. cracks and clods) in determination of soil hydraulic parameters at the plowed layer may improve the simulation results of soil moisture.

• 한국환경농학회지
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• 제36권3호
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• pp.141-146
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• 2017

BACKGROUND: Phosphorus(P) is a vital factor for rice but excess input of phosphorus fertilizer can cause environmental risk and waste of fertilizer resources. We studied to assess the change of available phosphate, P balance, critical concentration of available phosphate under a rice single system. METHODS AND RESULTS: The changes of available phosphate of paddy soil were examined from long-term fertilization experiment which was started in 1954 at the National Academy of Agricultural Science. The treatments were no phosphate fertilization(No fert., and N), phosphate fertilization(NPK, NPKC, and NPKCLS). The available phosphorus concentrations in treatments without phosphate fertilizer (No fert. and N) were decreased continuously. But, after 47 years, available phosphate content in phosphate fertilizer treatment (NPK, NPKC, and NPKCLS) reached at the highest ($245{\sim}331mg\;kg^{-1}$), showing a tendency to decrease afterward. The mean annual P field balance in these treatments (NPK, NPKC, and NPKCLS) had positive values that varied from 16.6 to $17.5kg\;ha^{-1}year^{-1}$, and ratio of residual P were increased. These showed that phosphate fertilizer in soil were converted into the form of residual phosphorus which was not easily extracted by available phosphate extractant. Also, It was estimated that the critical value of available phosphate for rice cultivation was $120mg\;kg^{-1}$ using Cate-Nelson equation. CONCLUSION: We concluded that no more phosphate fertilizer should be applied in rice single system if soil available phosphate is higher than the critical P value.

• 한국토양비료학회지
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• 제43권6호
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• pp.911-916
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• 2010

농업활동 중 경종분야인 벼재배와 작물잔사 소각은 온실가스인 메탄의 주 발생원이다. 이번 연구는 1990년부터 2008년까지 우리나라 경종분야에서 발생하는 메탄 배출량을 평가하기 위해 수행되었다. 우리나라에서 벼 재배에 의한 메탄 배출량은 1990년 395 천 톤에서 2008년 297 천 톤으로 벼 재배면적의 감소에 따라 지속적으로 감소하는 경향을 보였다. 작물잔사 소각에 의한 메탄 배출량은 1990년 2,502 톤에서 2008년 2,726 톤으로 작물별 차이는 있었으나 연도별 전체 배출량에는 큰 변화없이 일정한 값을 유지하였다. 작물잔사 소각에 의한 메탄 배출은 경종부분 전제 배출량에는 큰 영향을 미치지 않았다. 벼재배와 작물잔사 소각에 의한 총 메탄 배출량을 이산화탄소로 환산한 값은 1990년 8,356 천 톤 $CO_2$-eq.에서 2008년 6,287 천 톤$CO_2$-eq.로 나타났다. 농업부문의 온실가스 배출량 평가의 정확도 제고를 위해서는 활동자료의 신뢰성 확보가 무엇보다도 중요하다. 2010년부터 농촌진흥청과 통계청이 공동으로 활동자료의 공식적인 조사를 시작하였으며, 이러한 체계적인 활동량 조사는 농업부문 온실가스 배출량 평가의 신뢰도 향상과 불확도 저감에 크게 기여할 것으로 예상된다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.308-308
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• 2017

The low and unstable yield of soybean has been a major problem in Japan. Excess soil moisture conditions are one of the major factors to restrict soybean productivity. More than 80 % of soybean crops are cultivated in converted paddy fields which often have poor drainage. In central and eastern regions of Japan, the early vegetative growth of soybean tends to be restricted by the flooding damage because the early growth period is overlapped with the rainy season. Field observation shows that induced excess water stress in early vegetative stage reduces dry matter production by decreasing intercepted radiation by leaf and radiation use efficiency (RUE) (Bajgain et al., 2015). Therefore, it is necessary to evaluate the responses of soybean growth for excess water conditions to assess these effects on soybean productions. In this study, we aim to modify the soybean crop model (Sinclair et al., 2003) by adding the components of the restriction of leaf area development and RUE for adaptable to excess water conditions. This model was consist of five components, phenological model, leaf area development model, dry matter production model, plant nitrogen model and soil water balance model. The model structures and parameters were estimated from the data obtained from the field experiment in Tsukuba. The excess water effects on the leaf area development were modeled with consideration of decrease of blanch emergence and individual leaf expansion as a function of temperature and ground water level from pot experiments. The nitrogen fixation and nitrogen absorption from soil were assumed to be inhibited by excess water stress and the RUE was assumed to be decreasing according to the decline of leaf nitrogen concentration. The results of the modified model were better agreement with the field observations of the induced excess water stress in paddy field. By coupling the crop model and the ground water level model, it may be possible to assess the impact of excess water conditions for soybean production quantitatively.

• 한국토양비료학회지
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• 제46권6호
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• pp.409-416
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• 2013

Millet and sorghum are major dryland cereal crops, however their growth and productivity is limited by soil water stress with varying intensity. The major objective of this study was to evaluate water stress of millet and sorghum yield under drainage classes of poorly drained soil and to test the effect of the installed pipe drainage in poorly drained paddy soil to minimize crop stress. The research was carried out in poorly drained paddy fields located at alluvial slopping area resulting in non-uniform water content distribution by the inflow of ground water from the upper part of the field. Stress Day Index (SDI) was determined from a stress day factor (SD) and a crop susceptibility factor (CS). SD is a degree of measurement by calculating the daily sum of excess water in the profile above 30cm soil depth ($SEW_{30}$). CS depends on a given excess water on crop stage. The results showed that sum of excess water day ($SWD_{30}$) used to represent the moisture stress index was lower on somewhat poorly drained soil compared with poorly drained soil on 117 days. CS values for sorghum were 57% on $3^{rd}$ leaf stage, 44% on $5^{th}$ leaf stage, 37% on panicle initiation, 23% on boot stage, and 16% on soft dough stage. For proso millet CS values were 84% on $3^{rd}$ leaf stage, 70% on $5^{th}$ leaf Stage, 65% on panicle initiation, 53% on boot stage, and 28% on soft dough stage. And for foxtail millet the values were 73% on $3^{rd}$ leaf stage, 61% on $5^{th}$ leaf stage, 50% on panicle initiation, 29% on boot stage, and 15% on soft dough stage. SDI of sorghum and millet was more susceptible to excess soil water during panicle initation stage more poorly drained soil than somewhat poorly drained soil. Grain yield was reduced especially in proso millet and Foxtail millet compared to Sorghum.

• 식물병과 농업
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• 제5권2호
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• pp.77-83
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• 1999

In 1997 surveys 82 out of 180 crucifer fields were infected with clubroot disease in a range of 1-100% of diseased plants and among crucifier crops Chinese cabbage was the most severe, In cropping systems Chinese cabbage-monocropping of Chinese cabbage-radish were found to be most common in major Chinese cabbage production areas. Welsh onion squash or paddy rice were also planted between cropping of Chinese cabbage. Paddy fields converted to upland were lowered in incidence of clubroot disease and fields with loam to silty loam soil were more severe in disease than those with sandy soil. Soil pH and organic contents were nor related to clubroot disease severity. Soil fauua such as total fungi bacteria actinomyces Pseudomonads and Bascillus were not correlated with severity of the disease. Root rall development on Chinese cabbage seedlings was initifially observed under a microscope 13 days after inoculation with Plasmodiophora brassicae but 18 days by naked eyes after inoculation. Root galls were formed mostly around collar roots and gradually spread to main root lateral roots and secondary root branches. Root galls started to enlarge greatly in size and weight from 23 days after inoculation. Chinese cabbage plants at mid-growth stage with root gall development were reduced to 1/2 of that of healthy plants in number of leaves 1/4-1/5 in above ground fresh weight 1/6 in root length but increased to 3 times in diameter of collar root. Diseased plants had little root hairs. Diseased Chinese cabbage plants at harvest were reduced by 9,1-11.8% in head weight compared to healthy plants a positive correlation was observed between root and head weight but those relationships were rot found in the diseased plants.

• 한국환경농학회지
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• 제21권2호
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• pp.136-143
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• 2002

물관리방법을 달리한 상시담수와 간단관개에서 메탄과 아산화질소의 배출 양상과 서로 다른 종류의 유기물원 및 질소비료 시용에 따른 메탄과 아산화질소 배출을 비교하고 저감할 수 있는 방법을 찾기 위해 본 시험을 실시하였다. 물관리 방법으로는 상시담수 (이앙$\sim$출수 35일까지 담수)와 이앙 35일 이후 중간낙수한 간단관개 (중간낙수기간 20일), 그리고 시비방법으로는 토양을 검정한 시비량인 토양검정, 토양 검정시비량+볏짚, 돈분액비, LCU 완효성비료, 그리고 N을 시용하지 않은 대조구 등을 처리하여 메탄 및 아산화질소 배출량을 측정하였다. 메탄 배출량은 간단관개보다 상시담수께서 높았고, 아산화질소 배출량은 이와 반대로 나타났다. 유기물과 비료시용 종류에 따른 메탄과 아산화질소 배출량은 액비와 검정시비+볏짚시용구에서 가장 높았으며, LCU 완효성비료구에서 가장 낮았다. 지구온난화잠재력으로 환산한 온실가스 배출은 물관리 조건에서 상시담수가 간단관개보다 170$\sim$208% 높았으며, 요소를 시용하고 상시담수를 기준 한 것과 간단관개로 물관리하여 각 처리에 따라 온실가스 배출을 비교하면, 요소는 41.4%, LCU 완효성비료 55.8%로 온실가스 배출을 줄일 수 있는 것으로 나타났다. 그리고 비료이용효율은 LCU 완효성비료, 액비>검정시비+볏짚>검정시비 순이었다.