• 한국자원식물학회지
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• 제30권3호
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• pp.318-322
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• 2017

The study was carried out to determine the changes of growth characteristics, anthocyanidin, and brown rice yield grown at coast and inland areas apart from the east coastline of Gyeongsangbuk-do province. Number of spikelets per panicle was much more increased in inland area. Regional difference in number of spikelets per panicle was observed in Jeongjinju cultivar. Among these red rice cultivars, the highest brown rice yield was Jeongjinju rice cultivar having 702 kg in inland area and 692 ㎏ in coast area, respectively. Anthocyanidin content ranged 524 to $610{\mu}g/g$ dry weight basis. Cyanidin content was 11.4 to 14.0 times higher than that of delphinidin under coast and inland area. Anthocyanidin content was higher in rice cultivar grown at coast area. Highest head brown rice rate was only observed in Geonganghongmi to 95.2 at coast area and 95.4 inland area. In considering brown rice yield and pigment content, Hongjinju rice cultivar was recommended in optimal pigment rice cultivar in eastern coast of Gyeongsangbuk-do Province.

• 한국작물학회지
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• 제51권2호
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• pp.130-136
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• 2006

Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas.

• 한국농공학회논문집
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• 제54권3호
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• pp.141-148
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• 2012

Food policy is considered as the most basic and central issue for all countries, while making efforts to keep each country's food sovereignty and enhance food self-sufficiency. In the case of Korea where the staple food is rice, the rice yield prediction is regarded as a very important task to cope with unstable food supply at a national level. In this study, Korean paddy Rice yield Prediction Model (KRPM) developed to predict the paddy rice yield using meteorological element and MODIS NDVI. A multiple linear regression analysis was carried out by using the NDVI extracted from satellite image. Six meteorological elements include average temperature; maximum temperature; minimum temperature; rainfall; accumulated rainfall and duration of sunshine. Concerning the evaluation for the applicability of the KRPM, the accuracy assessment was carried out through correlation analysis between predicted and provided data by the National Statistical Office of paddy rice yield in 2011. The 2011 predicted yield of paddy rice by KRPM was 505 kg/10a at whole country level and 487 kg/10a by agroclimatic zones using stepwise regression while the predicted value by KOrea Statistical Information Service was 532 kg/10a. The characteristics of changes in paddy rice yield according to NDVI and other meteorological elements were well reflected by the KRPM.

• 한국작물학회지
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• 제41권1호
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• pp.109-114
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• 1996

논토양에서 경운방법과 시비수준을 달리하여 화성벼를 5년간 동일포장에서 재배했을 때 벼수량과 토양특성 변화를 조사분석한 결과는 다음과 같다. 1. 기종별 경운효율은 경운기 로타리구가 74.8％로서 제일 높고 트랙타 경운구가 59.0％로서 가장 낮았다. 2. 벼 이앙후 무경운구의 감수심이 가장 많았으며 벼 생육중기보다는 생육초기에서 많았다. 3. 벼 수량은 무경운 관행시비에 비해 경운기 로타리 농토배양시비구가 가장 많은 17％가 증수되었고 경운처리를 하므로서 벼수량은 6∼17％ 증수되었다. 연차간에는 2연차에서 수량이 가장 많았고 4년차에서 가장 낮았다. 4. 경운하지 않은 무경운구의 용적밀도와 고상률이 가장 높았으며 토양의 화학성 변화는 처리간에 일정한 경향이 없었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.383-392
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• 1993

Identification of rice paddy fields and estimation of their areas from the images taken by LANDSAT-5/TM were attempted. The results were verified by aerial photographs and also by ground observations. Changes of the spectral characteristics of rice plants were measured with a portable spectroradiometer during the growth period. Analyzing these characteristics, an index was developed for evaluating the growth and the yield of rice . Applying the index to the data observed by LANDSAT-5.TM on Sep. 26, 1986, Oct .20, 1989 and Sep, 21, 1990, it was confirmed that the estimated derived from the index agreed with actual values. The results well demonstrated its feasibility for evaluating the yield of rice by a satellite like LANDSAT-5/TM.

• 한국환경과학회지
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• 제30권8호
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• pp.659-671
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• 2021

The physicochemical properties of soil and the yield and quality of rice (Oryza sativa L. cv. Sailmi) were assessed using Italian ryegrass (Lolium multiflorum Lam. cv. Kowinearly)-rice double cropping systems in the paddy fields at Goseong and Miryang in southern Korea. The average temperatures during the ripening period were approximately 1 ℃ higher than the optimal temperature for rice ripening and the sunshine duration was reduced by frequent rainfall. Consequently, it was slightly below the optimal conditions required for rice ripening. In the soil at Goseong, winter Italian ryegrass cropping increased the pH, electrical conductivity, and the contents of organic matter, total nitrogen (T-N), available P₂O₅, K, Ca, and Mg than winter fallowing. Particularly, the contents of T-N and available P₂O₅increased significantly. In the soil at Miryang, Italian ryegrass slightly increased the electrical conductivity and the T-N, Mg, and Na contents. Therefore, winter Italian ryegrass cropping improved the physicochemical properties of paddy soils; however, Italian ryegrass-rice double cropping slightly reduced the culm length at both Goseong and Miryang, without markedly changing the panicle length or number compared to fallow-rice cropping. Furthermore, at Goseong, Italian ryegrass-rice double cropping slightly decreased the spikelet number and milled rice yield, and increased the ripened grain rate; however, at Miryang, contrasting results were observed. In addition, fallow-rice cropping revealed no differences in the head rice or opaque rice rates. The protein content was slightly increased in Italian ryegrass-rice double cropping, without significant changes in the amylose content or Toyo value, compared to that in fallow-rice cropping. The peak and breakdown viscosities were slightly decreased. These results indicate that winter Italian ryegrass cropping might alter rice taste but may not exhibit remarkable negative effects on rice cultivation. Therefore, Italian ryegrass-rice double cropping system is recommended for paddy fields in southern Korea. Nevertheless, to increase the rice yield and quality, fertilization standards for rice cropping that consider the changes in the T-N and organic matter contents in paddy fields caused by winter Italian ryegrass cropping need to be established.

• 생태와환경
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• 제55권4호
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• pp.341-351
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• 2022

The physiological characteristics, growth, and yield of each regional rice variety ('Odaebyeo', 'Saechucheong', 'Ilmibyeo') were investigated depending on the impact of changes in temperature and CO₂ concentration. Experiments were conducted with a control group, which reflected atmospheric CO₂ concentration and temperature, and treatment groups, in which the CO₂ concentration and temperature were increased by 250 ppm and 2.0℃ from those in the control group. The results showed that the increase in CO₂ concentration and temperature reduced the growth and yield of the rice 'Odaebyeo', but did not substantially change the productivity of the 'Saechucheong' and 'Ilmibyeo'. The increase in CO₂ concentration and temperature increased stomatal conductance and rate of transpiration of the 'Odaebyeo' variety, thereby decreasing its water use efficiency (WUE). In contrast, the increase in CO₂ concentration and temperature increased the photosynthetic rate and WUE of the 'Saechucheong' and 'Ilmibyeo' varieties. The gradual change in climate is considered to directly affect growth and development of rice and diversely affect the productivity of each variety. Therefore, it is necessary to implement technological development, select regionally optimal rice varieties, develop new rice varieties, as well as conduct long-term monitoring of each rice variety for climate adaptation to counter global warming.

• 한국환경농학회지
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• 제41권1호
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• pp.16-23
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• 2022

BACKGROUND: Rice production by the current standard cultivation method is predicted to decrease due to global warming. It seems that there has been a strong warming trend in Hwaseong-si, Gyeonggi-do. This study attempted to understand the climate change in Hwaseongsi, Gyeonggi-do and to analyze the effect of climate change on rice production. METHODS AND RESULTS: The statistical and physicochemical analyses were performed using the rice cultivar 'Chucheongbyeo' yields grown at the rice paddy field plot in the Gyeonggi-do Agricultural Research and Extension Services and the weather data measured in near the rice paddy plot. CONCLUSION(S): There was no significant difference between the average rice yields per area in 2000s (2001~2010) and 2010s (2011~2020), but the rice yield variability was greater in 2010s than in 2000s. The mean, minimum, maximum temperature, and the sunshine hours were evaluated for the correlation with the rice yield. The understanding of climate change in Hwaseong-si, Gyeonggi-do and the major weather factors affecting changes in rice yield, presented in this study, would enhance scientific understanding of regional climate change, and improve rice cultivation management.

• 한국작물학회지
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• 제58권1호
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• pp.28-35
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• 2013

Anthocyanin pigments from three pigmented rice varieties, Hongjinju, Sintoheugmi and Josaengheugchal pigmented by black color, were quantified to evaluate effects of transplanting and harvesting time during seed development. Hongjinju, a rice variety of grains pigmented by red color, contains only two kinds of anthocyanins, delphinidin and cyanidin. Meanwhile, delphinidin, cyanidin, and pelargonidin were identified in Sintoheugmi and Josaengheugchal. Anthocyanidin contents in pigmented rice variety Hongjinju under different planting times were decreased with prolonged harvesting times. The Sintoheukmi showed that cyanidin content was the highest among analyzed pigments during seed development. Two anthocyanins (cyanidin and pelargonidin) in Josaengheugchal recorded highest contents at 20 days after heading in three transplanting times. Cyanidin content was also slightly increased with prolonged transplanting time. Total anthocyanidin contents in Hongjinju were always lower than that of Sintoheukmi and Josaengheukchal. In two rice varieties, Sintoheugmi and Josaengheugchal, $a^*$ values were commonly slightly decreased by late transplanting and harvesting times. Changes of $a^*$ and $b^*$ values in waxy rice varieties, Sintoheugmi and Josaengheugchal varied more than those in Hongjinju. In Josaengheugchal, early harvesting before maturity showed lower brown rice yield and late harvesting in the each transplanting times resulted in highest brown rice yield.

• 환경생물
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• 제32권4호
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• pp.327-334
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• 2014

Emission reduction of $CH_4$ (methane gas) from rice paddy soil is a very important measure for climate change mitigation in agricultural sector. In this study, we investigated the changes in crop yield and $CH_4$ emissions in response to application of biochar and fertilizers. The experimental site is located in Hwasung, Kyunggido and experimental design is the split-plot method with three replicates. Treatments included rice straw (RS) and biochar (BC) amendments nested with the conventional NPK fertilizer (NPK) and slow release fertilizer (SRF). Control was also prepared with the soil with the conventional NPK fertilization with no amendment. Measurement of $CH_4$ emission was conducted during the growing season of 2014 using a dynamic chamber method. The results showed that application of rice straw increased daily $CH_4$ emission rate by 15%, while application of biochar reduced daily $CH_4$ emission rate by 38%. When we combined biochar application with slow release fertilizer, $CH_4$ emission was reduced by 45%. Further, the crop yield was also increased in all treatments compared with the control except for the treatment of rice straw application with slow release fertilizer. Overall results imply that biochar amendment to agricultural soil can be an effective strategy to decrease annual $CH_4$ emission with no reduction in crop yield.