• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.479-484
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• 1999

Rice crop has relatively short growing season during the summer in Korea and, therefore, it is often difficult to acquire cloud-free imagery on time. This study was attempt to define the temporal characteristics of radar backscattering observed from satellite L-band SAR data on different growing stages of rice crop. Six scenes of multi-temporal JERS SAR data were obtained from the transplanting season to the harvesting month of October. Six layers of multi-temporal SAR data were registered on a common geographic coordinate system. Using topographic maps, field collected data, and Landsat TM data, several sample rice fields were delineated from the imagery and their relative radar backscatters were calculated by using a set of reference targets. The temporal pattern of radar backscattering was very distinctive by the growing stage of rice crop. It was also separable between two types of rice fields having different cultivation practices. Considering the temporal characteristics of radar backscattering observed from the study, it is obvious that a certain date of the growing season can be more effective to delineate the exact area of the cultivated rice crop field.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.418-423
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• 1999

This study was performed to find an efficient method to overcome extremely high temperature within greehhouse in summer season. The actual states of practical use for greenhouse in hot summer season were investigated. About 21.6% of the investigated greenhouse farms were no cultivation, and most greenhouse farms were cultivating under the very inferior environment . To examine thermal enviornment of greenhouse according to cooling or assistant cooling , greenhouses were treated with natural ventilation, shading, roof sprinkling , and evaporative cooling with air cool fan. Shading and operating air col fan showed a drop in temperature of 3.8∼4.2$^{\circ}C$ as compared with natural ventilation, and most greenhouse air temperatures were maintained below 35$^{\circ}C$.

• Journal of Biosystems Engineering
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• 제16권4호
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• pp.399-407
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• 1991

In Korea, the cultivation area under the plastic greenhouse was 1,746 ha in 1975, and 36,656 ha in 1989, it shows that the greenhouse cultivation area was increased by 21 times during last 14 years. The greenhouse cultivation area of 90~93% has been kept warm with double layers of plastic film and thermal curtain knitted with rice straw, and the rest area of 7~10% has been heated by fossil fuel energy. The use of rice straw thermal curtain is inconvenient to put it on and off, on the other hand the use of fossil fuel heating system results in the increase of production cost. To solve these problems, at first the heating load and the storable solar energy in greenhouse during the winter season were predicted to design solar utilization system, secondly a solar thermal storage system filled with latent heat storage materials was developed in this study. And then finally the thermal performance of greenhouse-solar energy storage system was analyzed theoretically and experimentally.

• 한국작물학회지
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• 제49권3호
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• pp.199-206
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• 2004

Typhoon "MAEMI", happened in September 2003, hit the great damage to Gyeongnam province area. Especially, rice plant was lodged or severe leaf damage was caused. This study was conducted to find out the extents of leaf damage among different rice cultivars, and to evaluate rice yield and eating quality due to leaf damage after typhoon. Rice cultivars torn off over half of the flag leaf length (FLL) were one medium-late maturing cultivar (Donginl), medium maturing cultivar (Yeonganbyeo), eight early maturing cultivars (Samcheonbyeo, Jounghwnbyeo, Munjangbyeo, Taebongbyeo, Odaebyeo, Samhaegbyeo, Sobaegbyeo, Sinunbongbyeo), two long-il type cultivars (Samgangbyeo, Namcheonbyeo), and three special use cultivars (Heukseonchalbyeo, Jinbuchalbyeo, Yangjobyeo). Cultivars torn off below 1/10 FLL were eight medium-late maturing cultivars (Chucheongbyeo, Daecheongbyeo, Saechu cheongbyeo, Donganbyeo, Daeyabyeo, Hwamyeongbyeo, 방eongsanbyeo, Dongjinbyeo) and two medium maturing cultivays (Donghaebyeo, Gumobyeo2). The rest cultivars were tore off by 1/10∼1/2 ELL. In yield components, the longer was flag leaf damage, the lower was ripened grain ratio, grain weight and brown/rough rice ratio, which was severly impacted to late than to ordinary season cultivation. However, rice yield did not decrease up to tearing by 1/10 ELL. Head rice ratio decreased from flag leaf tearing over 1/10 ELL in late season cultivation. The longer was flag leaf damage, the lower was eating quality, which could not show significantly different.

• 한국환경농학회지
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• 제15권3호
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• pp.348-354
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• 1996

This study was carried out to investigate factors influencing on the groundwater quality at controlled horticulture in Honam area in 1995. The deeper groundwater sampling, the lower concentrations of $NH_4-N$ and $NO_3-N$ were observed. There was no difference in concentrations of $SO_4\;^{2-}$ and $Na^+$ in the groundwater below 15m. Contents of $NH_4-N$, $NO_3-N$ and $PO_4\;^{3-}$ in groundwater were the highest at rice transplanting season(the late May) and that of $SO_4\;^{2-}$, $Na^+$ and $Cl^-$ were the highest at dry season(the mid-February). Continuous cultivation of horticultural crops showed higher concentration of $NH_4-N$, $NO_3-N$, $PO_4\;^{3-}$, $Na^+$ and $Cl^-$ in groundwater than rotational culture with rice. The longer cultivation years with horticultural crops, the higher concentrations of $NO_3-N$, $PO_4\;^{3-}$, $SO_4\;^{2-}$ and $Cl^-$ were shown, and constitutional ratio of $NO_3-N$ among the anions increased gradually. Nitrate-N level, exceeded 20mg/l, the critical level for agricultural usage, frequently at Yongjinmyeon Wanju and Janglockdong Kwangju, and $PO_4\;^{3-}$ levels were higher at Seogtandong Iksan than the other places.

• 한국작물학회지
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• 제58권1호
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• pp.43-49
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• 2013

바이러스 무병묘의 만기재배를 통한 우량 씨고구마의 안정적 생산과 적응품종 선발을 위하여, 9 품종의 바이러스 무병묘와 농가묘를 7월 10일 $75{\times}25cm$로 정식하여 흑색비닐로 멀칭재배를 한 다음, 생육특성 및 수량 등을 조사하였다. 1. 정식 30일째의 초기생육은 농가묘보다 무병묘에서 줄기 길이, 줄기 직경, 마디수, 곁가지수 등이 유의하게 증가하였고, 품종 간에도 유의한 차이를 보였으며, '고건미', '신천미', '신황미', '신율미', '연황미' 등에서 초기생육이 양호하였다. 2. 정식 110일째의 지상부 생육에서 줄기 길이, 줄기 직경, 마디수, 분지수 및 생체중 등은 품종간에 유의한 차이를 보였으나, 무병묘와 농가묘간에는 마디수 외에 다른 형질들은 유의한 차이를 보이지 않았다. 3. 만기재배에 따른 무병묘 수량은 품종에 따라 농가묘보다 12-49% 증수되었으며, 무병묘와 농가묘간 평균수량은 각각 1,625 kg/10a과 1,230 kg/10a 으로 무병묘에서 유의하게 증가하였다. 4. 씨고구마로 이용할 수 있는 40 g 이상의 상저비율은 무병묘 65.6%, 농가묘 57.8%로 무병묘에서 유의하게 증가하였으며, 무병묘와 농가묘간 상저수량은 각각 1,067 kg/10a과 710 kg/10a 이었다. 5. 공시된 9품종 중에서 1,300 kg/10a 이상의 상저수량을 보인 '신자미', '신천미', '신율미' 등 3품종의 만기재배 적응성이 높았다.

• 한국환경농학회지
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• 제42권3호
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• pp.211-219
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• 2023

중량식 라이시미터를 이용하여 사양질과 식질 토양에서 동계 작물인 청보리 재배 여부에 따른 양분 유출과 양분 수지를 평가하였다. 양분 유출과 관련된 지하 배수량은 식질에서 가장 많았으며, 동계 작물 재배 여부에 따른 토양 수분함량을 비교해보면 나지에서는 사양질과 식질 토양 모두 30-40%를 유지하였고, 청보리 재배구는 생육 재생기인 3-4월에 평균 증발산량이 평균 2.1-6.7 mm·day^-1이었으며, 토양 수분함량은 18.1-21.8%까지 낮아졌다. 동계작물 재배 시 봄철 생육재생기에 생체량이 증가함에 따라 증발산량도 증가하기 때문에 수분이 지상부로 이동하므로 양분의 지하유출을 예방할 수 있을 것으로 판단된다. 또한 사양질 토양에서 청보리의 재배에 따른 양분수지는 비료 공급량에 비해 작물 흡수량이 많아 음의 값을 나타냈으며, 토양에 집적된 양분을 이용했을 것으로 추측된다. 따라서 동계에 적정량의 비료를 주고 사료작물을 재배하면 경지 이용률을 높이고, 양분수지를 낮추는데 도움이 될 것으로 판단된다.

• 한국자원식물학회지
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• 제35권3호
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• pp.399-404
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• 2022

Russian dandelion, Taraxacum kok-saghyz L.E.Rodin, is an important alternative source of natural rubber. Thus, it is critical to identify the best season for natural rubber production and harvesting for this species. In this study, T. kok-saghyz was grown in experimental fields in Korea to check the variation in rubber content with the change in the season. Studies using T. kok-saghyz plants indicate that spring and autumn are the best seasons for rubber accumulation. For several reasons, our study suggests that planting in autumn and harvesting in late spring is the best strategy for economic cultivation in Korea. Our data will be useful for future commercialization of rubber production from T. kok-saghyz because time will be saved if the plant is grown and harvested in the optimum season.

• 한국유기농업학회지
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• 제14권3호
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• pp.305-313
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• 2006

대단위 오리농법 지역에서 오리방사 대신 두과작물인 헤어리베치를 사용하여 유기 벼재배 현장에서 효과 검정을 수행한 결과는 다음과 같다. 1) 유기벼 재배시 휴한기에 헤어리베치를 재배함으로서 오리농법 재배 외에 친환경 비료절감 기술로도 이용이 가능하였음. 2) 두과작물인 헤어리베치를 활용함으로서 토양의 물리성 및 작물 생산성 확보가 가능하였음. 3) 두과작물인 헤어리베치 시용으로 대단위 오리농법에 의한 농업용수 수질오염에 대한 효과도 있었음.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.853-857
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• 2007

The semi-outdoor cultivation of Spirulina platens is was attempted using an underground-water-based medium. Occurrence of contaminant organisms such as Chlorella sp. and Chlamydomonas sp. was not found from a microscopic observation and bacteria were not detected from denaturing gradient gel electrophoresis(DGGE) analysis of PCR-amplified 16S rDNA during the cultivation, owing to pH control and the high quality of the underground water. The mean productivity was high at $10.5g/m^2/d$ with a range of $4.2-12.3g/m^2/d$ despite the unfavorable weather conditions of the rainy season. The cultivated S. platens is included a normal protein content of 58.9%. Consequently, the underground water improved the biomass productivity and the biomass quality because of an abundant supplementation of natural minerals and through a contaminant-free culture.