• 한국작물학회지
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• 제50권2호
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• pp.73-78
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• 2005

Demand for the domestic hairy vetch seed production will be increased with the increasing interest of environment-friendly agriculture in Korea. This study was conducted during from 2000 fall to 2003 spring at upland field of National Institute of Crop Science in Suwon, Korea to compare wheat and triticale (TC) as stake crop of hairy vetch (HV), and to know proper seeding rates and ratios between TC and HV for the maximum HV seed production. As supporting crop of HV, TC was superior to wheat at the points of higher HV seed yield, stronger TC stalk for supporting, consistence of ripening stage of two seeds. In seeding method, row seeding was superior to broadcast seeding at the points of less lodging and higher HV seed yield. HV seed yield decreased with the increase of TC seeding rate in mixture cropping (row seeding), particularly at TC seeding rates over 5kg/10a. HV seed yield increased with the increase of HV seeding rate at the condition of TC seeding rates under 5kg/10a in spite of higher lodging of mixed crops at higher HV seeding rate due to higher HV aboveground dry matter. Maximum HV seed yield was obtained at TC seeding rate of $1\~1.5kg/10a$ as indicating HV seed yield 176kg/l0a (CV. Madison) at seeding rate of TC 1kg/10a + HV 2 kg/10a in 2001, and HV seed yield 96kg/10a (CV. Common) at seeding rate of TC 1.5kg/10a + HV 4.5kg/10a in 2003. Use of all-purpose combine harvester for harvesting and appliance for separation of mixed seeds using centrifugal force, which are prerequisite for HV seed production, was excellent in the simultaneous seeds production system of HV and TC.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.79-79
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• 2017

Grain Sorghum varieties grown in Korea have low productivity and are constrained by the fact that farmers' choice of improved varieties is limited. Hybrid cultivars have been demonstrated to be more productive and food security than pure line varieties. However, There's no available hybrid cultivars and never planted before in Korea. This study was, therefore, conducted to determine combining ability of Korean landrace varieties and cultivar, the level of heterosis of experimental hybrids depending on environments. Two cytoplasmic male-sterile lines were crossed with six male-fertile lines in accordance with North Carolina II mating scheme to generate 12 experimental hybrids. The hybrids were evaluated in replicated row-column alpha designs at two sites in Texas and South Korea under on-season production conditions. For each trait, general combining ability (GCA) and specific combining ability (SCA) effects were estimated using the line-tester method of analysis. Results indicated significant differences among genotypes for both grain yield potential and secondary traits. Hybrids were predominant for grain yield, and displayed up to 127% heterosis of A03017 ${\times}$ Sodamchal in Korea. Positive GCA for yield was observed for Donganme, Hwanggeumchal and Jungmo4002 in Korea. Among them Jungmo4002 and Donganme had highly positive for yield (227.90 and 84.90 kg ha-1), while it showed negative GCA for yield in College station (-40.90, -189.60 kg ha-1). ATx630 ${\times}$ Sodamchal had the greatest SCA for yield (468.10 kg/ha) in College station but at South Korea its SCA effect was -302.40 kg/ha. A similar trend was observed, followed by A03017 ${\times}$ Donganme (SCA effect = 215 kg ha-1 at College station vs. -44.20 kg ha-1 at South Korea). At South Korea the greatest positive SCA effect for grain was observed in ATx630 ${\times}$ Jungmo4002 as 322.20 kg/ha. Both GCA and SCA effects significantly interacted with site effects demonstrating the need for region adaptation of potential cultivars and test for developing Korea suitable cultivar.

• 한국측량학회지
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• 제34권4호
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• pp.383-390
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• 2016

Remote sensing data has been widely used in the estimation of crop yields by employing statistical methods such as regression model. Machine learning, which is an efficient empirical method for classification and prediction, is another approach to crop yield estimation. This paper described the corn yield estimation in Iowa State using four machine learning approaches such as SVM (Support Vector Machine), RF (Random Forest), ERT (Extremely Randomized Trees) and DL (Deep Learning). Also, comparisons of the validation statistics among them were presented. To examine the seasonal sensitivities of the corn yields, three period groups were set up: (1) MJJAS (May to September), (2) JA (July and August) and (3) OC (optimal combination of month). In overall, the DL method showed the highest accuracies in terms of the correlation coefficient for the three period groups. The accuracies were relatively favorable in the OC group, which indicates the optimal combination of month can be significant in statistical modeling of crop yields. The differences between our predictions and USDA (United States Department of Agriculture) statistics were about 6-8 %, which shows the machine learning approaches can be a viable option for crop yield modeling. In particular, the DL showed more stable results by overcoming the overfitting problem of generic machine learning methods.

• 한국농공학회논문집
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• 제52권3호
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• pp.57-64
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• 2010

The impacts of climate change on yield and evapotranspiration of rice have been modeled using AquaCrop model developed by Food and Agriculture Organization (FAO). Climate change scenario downscaled by Mesoscale Model 5 (MM5) regional model from ECHO-G General Circulation Model (GCM) outputs by Korea Meteorological Research Institute (METRI) was used in this study. Monthly average climate data for baseline (1971-2000) and three time periods (2020s, 2050s and 2080s) were used as inputs to the AquaCrop model. The results showed that the evapotranspiration after transplanting was projected to increase by 4 % (2020s), 8 % (2050s) and 14 % (2080s), respectively, from the baseline value of 464 mm. The potential rice yield was 6.4 t/ha and water productivity was 1.4 kg/$m^3$ for the baseline. The potential rice yield was projected to increase by 23 % (2020s), 55 % (2050s), and 98 % (2080s), respectively, by the increased photosynthesis along with the $CO_2$ concentration increases. The water productivity was projected to increase by 19 % (2020s), 44 % (2050s), and 75 % (2080s), respectively.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 춘계 학술대회지
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• pp.248-249
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• 2000

• 한국농공학회지
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• 제31권4호
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• pp.50-58
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• 1989

An approach to irrigation scheduling for chinese caggage is presented, and a crop yield response function to soil moisure is derived from irrigation experiments, based on a root- zone water balance method. The paper concludes that crop yield can be estimated by allowable depletion and actual evapotranspiration in 3 cropping stages, and presents the optimal allowalbe depletion, irriga- tion frequency and the amount of irrigation water to get the maximum crop yield and opti- mal irrigation policy.

• 한국작물학회지
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• 제61권2호
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• pp.104-112
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• 2016

A double-cropping system with soybean (Glycine max) following the cultivation of potato, garlic, and onion is widely adopted in the southern region of Korea. For this system, marginal dates for planting must be determined for profitable soybean yields, because the decision to plant soybean as a second crop is occasionally delayed by harvest of the first crop and weather conditions. In order to investigate the effect of planting date on soybean yield, three cultivars (early and late maturity) were planted on seven different dates from May 1 to July 30 in both paddy and upland fields across 2012 and 2013. Soybean yields were significantly different among the planting dates and the cultivars; however, the interaction between cultivar and planting date was not significant. Based on linear regression, the maximum yield of soybean was reached with a June 10 planting date, with a sharp decline in yield for crops planted after this date. The results of this study were consistent with those of a previous one that recommends early and mid-June as the optimum planting period. Regardless of soybean ecotype, a reduction in yield of greater than 20% occurred when soybean was planted after mid-July. Frost during soybean growth can reduce yields, and the late maturity cultivars planted on July 30 were damaged by frost before completing maturation and harvest; however, early maturity cultivars were safely harvested. For sufficient time to develop and reach profitable yields, the planting of soybean before mid-July is recommended.

• 한국작물학회지
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• 제67권4호
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• pp.342-361
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• 2022

우리나라 주요 재배 벼 품종의 고품질 쌀 생산을 위한 최적 질소 시비량을 제시하기 위하여, 우리나라 주요 벼 21품종을 공시하여 질소 시비량에 따른 수량과 품질변화를 검토한 결과는 다음과 같다. 1. 3년간 평균수량은 표준 질소 시비량 9 kg/10a으로 재배했을 때와 비교하여 질소 시비량 0, 3, 5, 7 kg/10a으로 재배했을 때 각각 28%, 22%, 11%, 8% 감소하였으며, 수량성과 질소 시비량 감소에 따른 수량 감소 경향은 품종별로 차이가 있었다. 2. 주당수수는 질소 시비량이 증가함에 따라 증가하였으나, 수랑립수와 천립중에는 큰 변화가 없었고, 수당립수는 다른 수량구성요소에 비해 상대적으로 연차변이가 적었으며, 질소 시비량에 따른 수량구성요소의 변화는 품종의 유전적 특성에 따라 큰 차이를 나타내었다. 3. 완전미율은 질소 시비량의 증가에 큰 영향을 받지 않고 어느 정도 일정하게 유지되는 경향을 나타내었고, 싸라기 비율은 약간 감소하였으며, 분상질립은 증가하였다. 4. 쌀의 단백질 함량은 2018과 2019년의 경우 질소 시비량이 증가할수록 감소하다가 질소 시비량 7 kg/10a에서 가장 낮았고, 9 kg/10a에서 다시 증가하는 경향을 나타내었으나, 2020년의 경우 질소 시비량이 증가함에 따라 지속적으로 증가하는 경향을 나타내었다. 5. 품종별로 표준 질소 시비량 9 kg/10a에서 시험기간 중 2회 이상 쌀 단백질 함량 6.0%를 초과한 품종은 해담 등 13품종으로 이중 질소 시비량을 7 kg/10a으로 감비하여 재배한 경우, 시험기간 중 2회 이상 쌀 단백질 함량이 6.0%이하로 낮아진 품종은 해담, 진수미, 호품, 호평, 현품, 새누리, 영호진미 등 7품종이었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.126-126
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• 2022

Climate change has continued to impact meteorological factors like rainfall in many countries including Nigeria. Thus, altering the rainfall patterns which subsequently affect the crop yield. Maize is an important cereal grown in northern Nigeria, along with sorghum, rice, and millet. Due to the challenge of water scarcity during the dry season, it has become critical to design appropriate strategies for planning, developing, and management of the limited available water resources to increase the maize yield. This study, therefore, determines the quantity of water required to produce maize from planting to harvesting and the impact of drought on maize during different growth stages in the region. Rainfall data from six rain gauge stations for a period of 36 years (1979-2014) was considered for the analysis. The standardized precipitation and evapotranspiration index (SPEI) is used to evaluate the severity of drought. Using the CROPWAT model, the evapotranspiration was calculated using the Penman-Monteith method, while the crop water requirements (CWRs) and irrigation scheduling for the maize crop was also determined. Irrigation was considered for 100% of critical soil moisture loss. At different phases of maize crop growth, the model predicted daily and monthly crop water requirements. The crop water requirement was found to be 319.0 mm and the irrigation requirement was 15.5 mm. The CROPWAT 8.0 model adequately estimated the yield reduction caused by water stress and climatic impacts, which makes this model appropriate for determining the crop water requirements, irrigation planning, and management.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.326-326
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• 2022

Natto is a soybean fermented food from Japan, which is made from steamed soybean, Bacillus natto and water. Demand of Natto has increased recently because it does not have smell compared to Cheonggukfang, which is Korean traditional fermented food. Currently, Pungsannamulkong is the most commonly used in Korea for Natto. Four candidate varieties of soybeans were investigated and compared in terms of Agronomic Traits, quality characteristics, hard seed rate, and water absorption rate in order to determine more suitable Korean soybean variety than pungsannamulkong. 'Haewon' had higher yield than other three varieties in Goesan-gun and Jinan-gun. The infected seed rate which affects soybean processing is higher in pungsannamulkong. 'Haewon' showed low 100 seed weight with 8.6 g in Goesan-gun and 9.5 g in Jinan-gun, which was the smallest of four soybean varieties. The water absorption rate was higher in 'Haewon' than in pungsannamulkong which is desirable characteristics for Natto process. The hard seed rate of pungsannamulkong was 6~7%, which is considered to be unsuitable to Natto process. The yield of Natto was significantly different for each variety. 'Haewon' showed the highest amino nitrogen content with 575.0 mg%. These results suggested that 'Haewon' can be considered as suitable candidates for yield and quality of Natto compared to pungsannamulkong.