• 대한원격탐사학회지
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• 제31권5호
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• pp.441-448
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• 2015

식량수급을 이해하기 위한 농업 현황 정보가 부족한 북한을 대상으로 위성영상과 기후자료를 이용하여 객관적이고 재현 가능한 벼 수량을 추정하는 방법을 개발하는 것을 본 연구의 목적으로 하였다. 2002년부터 2014년까지의 MODIS 위성 식생지수 평균 NDVI 최대값과 27개 관측지점의 9월 강수량 자료를 이용하여 북한의 벼 수량 값을 추정하였다. 모형의 결정계수는 0.44, RMSE는 0.27 ton/ha로 다소 크게 나타났고, 분산분석결과 F비가 3.0983, 유의확률이 0.1008을 보였다. 벼논 지역의 MODIS 평균 NDVI 최대값과 등숙기의 기후자료를 이용하여 추정한 북한의 벼 수량은 2007년이 2.71 ton/ha로 가장 낮게, 2006년이 3.54 ton/ha로 가장 높게 나타났다. 통계 값과 추정 값의 산점도를 통하여 비교한 결과 벼 수량이 약 3.3 ton/ha 보다 적을 때는 모형의 추정 값이 높고 그 이상일 때는 통계 값이 더 높게 나타나는 경향이었다. 모형의 종속변수와 독립변수로 사용되는 위성영상의 품질, 단일 시기의 벼논 마스크 영상, 기상 관측지점의 수와 자료의 품질, 통계 값의 품질 등으로 벼 수량에 대한 추정 성능의 한계가 있지만 객관적 자료를 사용하여 재현 가능한 방법을 제시하였다는 의미를 가진다. 모형 구동을 위해 사용되는 자료의 품질을 높여 나가야 하는 과제를 안고 있다.

• 한국토양비료학회지
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• 제35권3호
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• pp.169-174
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• 2002

본 시험은 겨울철 논에 헤어리벳치를 재배후 토양에 환원시키는 방법과 헤어리벳치 환원후 벼를 재배하였을 때 생육 및 쌀 수량에 미치는 영향을 구명하고자 1999년부터 2001년까지 3년간 작물시험장 논에서 수행되었으며, 그 결과는 다음과 같다. 헤어리벳치의 환원시기별 쌀 수량은 이앙 1주전 환원에 비하여 이앙 2~3 주전 환원시 7% 증가되었으며, 화학 질소비료를 무시용하고 벼를 재배할 수 있는 헤어리벳치의 적정 환원량은 $15{\sim}20ton\;ha^{-1}$이었고, 환원량이 $25ton\;ha^{-1}$일 경우 도복이 심하여 안전재배가 우려되었다. 헤어리벳치를 $20ton\;ha^{-1}$환원시 관행(질소 $110kg\;ha^{-1}$)에 비하여 $m^2$당 수수가 20% 증가되어 수량이 6% 정도 증가되었으며, 백미의 완전립 비율은 관행과 유사하였다.

• 한국초지조사료학회지
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• 제15권2호
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• pp.140-145
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• 1995

This experiment was canied out to investigate the effect of seeding times on the fresh yield of fodder beet varieties, and to select the most adaptable varieties of fodder beet in Daekwanryeong areas. Three varieties(Kyros, Zorba and Hugin) and six seeding times(25 July, 4 Aug. and 14 Aug. in 1993. and 30 Apr., 10 May and 20 May in 1994) were combined in the experiment. The results obtained were as follows: 1. The seeding time for the highest fresh yield of fodder beet was obtained as 18.29 tonha on 25 July in 1993. Of various varieties, the highest fresh yields were 22.59 ton and 18.89 tonlha for Kyros and Zorba on 25 July, and 19.15 tonha for Hugin on 4 Aug. in 1993. 2. The fresh yield of fodder beet were 20.30 ton, 19.41 ton and 16.93 tonlha on 30 Apr., 10 May and 20 May in 1994, respectively. The highest fresh yield of the varieties were 77.78 ton for Kyms on 20 May, 19.79 ton for Zorba on 30 Apr., and 20.63 tonha for Hugin on 10 May in 1994. 3. Shoot and root(S/R) ratio was different between seedling times. S/R ratio of the varieties were increased in 1993 due to the delayed seeding times, but on the contrary it tended to decrease in 1994 with the delayed seeding times. 4. Shoot and root(S/R) ratios of varieties were 0.94, 0.89 and 1.18 for Kyros, Zorba and Hugin in 1993, and 1.29 for Kyms, and 1.85 for Zorba and Hugin in 1994, respectively.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.518-518
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• 2016

Agriculture is the lifeblood of the economy in Ghana, employs about 42% of the population work force and accounts for 30% of the Gross Domestic Product (GDP). Corn (maize) is the major cereal crop grown as staple food under rain fed conditions, covers over 92% of the total agricultural area, and contributes 54% of the caloric intake. Issues of hunger and food insecurity for the entire nation are associated with corn scarcity and low production. The climate changes are expected to affect corn production in Ghana. This study evaluated variations of corn yields based on different climate conditions of rain-fed area in the Dangbe East District of Ghana. AquaCrop model has been used to simulate corn growing cycles in study area for this purpose. The main goal for this study was to predict yield of corn using selected climatic parameters from 1992 to 2013 using different climate scenarios. The Model was calibrated and validated using observed field data, and the simulated grain yields matched well with observed values for the season under production giving an R squared (R2)of 0.93 and Nash-Sutcliff Error(NSE) of 0.21. Study results showed that rainfall reduction in the range of -5% to -20% would reduce the yield from 1.315ton/ha to 0.421ton/ha (-21. 3%) whereas increasing temperature from 1% to 7% would result in the maximum yield reduction of -20.6% (1.315 to 1.09 ton/ha.). On the other hand, increasing rainfall from 5-20% resulted in yield increment of 68% (1.315-2.209 ton/ha) and decreasing temperature produce 7% increase in yield ( 1.315 to 1.401ton/ha). These results provide useful information to adopt strategies by the Government of Ghana and farmers for improving national food security under climate change.

• 생물환경조절학회지
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• 제6권2호
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• pp.92-96
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• 1997

단고추의 장기자루식 양액배지에 있어서 분지수가 생육과 수량에 미치는 영향을 구명하고자 1폿트당 4지, 6지, 8지를 유인하여 재배한 결과를 요약하면 다음과 같다. 1 초장, 경경, 엽중, 근중, 경중은 유의성은 없었으나 엽수와 엽면적은 8지유인에 많았다. 2. 과경, 과중은 4지 유인구에서 많았고 유의성은 없었으나 수량도 124.5ton/ha로 8지 유인의 113.4ton/ha보다 9% 많았다. 3. 유인방법별 월별 수량은 초기 5개월은 8지 유인이 4지 유인보다 많았으나 중기이후인 4월부터 수확 종료까지 4지 유인이 수량이 많았으며 유인에 따른 노동력 절감 및 상품율면에서 자루식 장기재배의 경우 4지 유인이 알맞을 것으로 사료되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권11호
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• pp.1592-1598
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• 2008

An experiment was carried out to study the effect of cattle slurry on maize fodder (Zea mays) production. Maize fodder was produced at 4 cattle slurry levels $T_0$ (0 ton/ha), $T_1$ (10 ton/ha), $T_2$ (12 ton/ha) and $T_3$ (14 ton/ha) in a randomized block design. Agronomic characteristics, plant heights, circumference of stems, number of leaves, leaf area and dry matter yield of maize fodder were measured. Maize plant height and stem circumference were significantly (p<0.01) influenced by the increasing rate of cattle slurry at 15, 30, 45 and 56 days after sowing. Number of leaves of fodder plants was not significant but leaf area was significant (p<0.05) among the treatment groups. The highest biomass yield (p<0.01) of maize fodder was observed in $T_2$ (44.0 ton/ha). For crude protein content, a significant difference (p<0.01) was observed in the treatment groups and the highest value was observed in $T_2$ (11.99%). Organic matter content of maize fodder showed a significant difference but ash, ADF and NDF contents showed no significant differences among treatment groups. From this study it may be concluded that the application of 12 tons of cattle slurry/ha was optimal for production of biomass and nutrient content of maize fodder.

• 한국물환경학회지
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• 제23권4호
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• pp.518-526
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• 2007

There have been serious soil erosion and water pollution problems caused by highland agriculture practices at Doam-dam watershed. Especially agricultural activities, chemical and organic fertilizer and pesticide applications, soil reconditioning to maintain soil fertility are known as primary causes of soil erosion and water qaulity degradation in the receiving water bodies. Among these, soil reconditioning can accelerate soil erosion rates. To develop soil erosion prevention practices, it is necessary to estimate the soil erosion from the watershed. Thus, the Universal Soil Loss Equation (USLE) model has been developed and utilized to assess soil erosion. However, the USLE model cannot be used at watershed scale because it does not consider sediment delivery ratio (SDR) for watershed application. For this reason, the Sediment Assessment Tool for Effective Erosion Control (SA TEEC) was developed to assess the sediment yield at any point in the watershed. The USLE-based SA TEEC system can estimate the SDR using area-based SDR and slope-based SDR module. In this study, the SATEEC system was used to estimate soil erosion and sediment yield at the Doam-dam watershed using the soil properties from reconditioned agricultural fields. Based on the soil sampling and analysis, the US LE K factor was calculated and used in the SA TEEC system to analyze the possible errors of previous USLE application studies using soil properties from the digital soil map, and compared with that using soil properties obtained in this study. The estimated soil erosion at the Doam-dam watershed without using soil properties obtained in the soil sampling and analysis is 1,791,400 ton/year (123 ton/ha/year), while the soil erosion amount is 2,429,900 ton/year (166.8 ton/ha/year) with the use of soil properties from the soil sampling and analysis. There is 35 % increase in estimated soil erosion and sediment yield with the use of soil properties from soil reconditioned agricultural fields. Since significant amount of soil erosion are known to be occurring from the agricultural fields, the soil erosion and sediment yield from only agricultural fields was assessed. The soil erosion rate is 45.9 ton/ha/year without considering soil properties from soil reconditioned agricultural fields, while 105.3 ton/ha/year after considering soil properties obtained in this study, increased in 129%. This study shows that it is very important to use correct soil properties to assess soil erosion and sediment yield simulation. It is recommended that further studies are needed to develop environment friendly soil reconditioning method should be developed and implemented to decrease the speed of soil erosion rates and water quality degradation.

• 한국자원식물학회지
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• 제22권3호
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• pp.220-226
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• 2009

An experiment was conducted to find out among 9 trap settings the most appropriate site for trap placement in the Brinjal field based on Brinjal shoot and fruit borer trapping efficiency, shoot and fruit infestation, healthy and total fruit yield, and BCR. The efficiency of different trap setting positions varied significantly. Trapping efficiency observed the $T_{1}$ ensured the minimum shoot and fruit infestation 10.02% and 20.95%, respectively, minimum infested fruit yield (4.75 ton/ha), maximum healthy and total fruit yield (26.72 and 31.47 ton/ha) and the maximum BCR (1.70), which was followed by $T_{2}$ and $T_{4}$. The minimum trapping efficiency of $T_{9}$ treatment led the maximum shoot and fruit infestation 13.89 and 29.26%, respectively, maximum infested fruit yield (7.59 ton/ha), minimum healthy and total fruit yield (17.74 and 25.32 ton/ha) and the minimum BCR (1.00). A correlation between the number of BSFB adults trapped from the most efficient trap setting and the shoot and fruit infestation recorded and found a linear positive correlation between number of BSFB adults trapped and shoot infestation (r = 0.781) and fruit infestation (r = 0.810). The effect of pheromone trap positions observed in this study may be attributed to the easy accessibility of the lures and traps, when they are placed at the canopy.

• 한국농공학회논문집
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• 제52권3호
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• pp.97-104
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• 2010

The purpose of this study is to evaluate sediment yield reduction under various field slope conditions with rice straw mat. The Vegetative Filter Strip Model-W (VFSMOD-W) and Soil and Water Assessment Tool (SWAT) were used for simulation of sediment yield reduction effect of rice straw mat. The Universe Soil Loss Equation Practice factor (USLE P factor), being able to reflect simulation of rice straw mat in the agricultural field, were estimated for each slope with VFSMOD-W and measured soil erosion values under 5, 10, and 20 % slopes. Then with the regression equation for slopes, USLE P factor was derived and used as input data for each Hydrological Response Unit (HRU) in the SWAT model. The SWAT Spatially Distributed-HRU (SD-HRU) pre-processor module was utilized, moreover, in order to consider spatial location and topographic features (measured topographic features by field survey) of all HRU within each subwatershed in the study watershed. Result of monthly sediment yield without rice straw mat (Jan. 2000 - Aug. 2007) was 814.72 ton/month, and with rice straw mat (Jan. 2000 - Aug. 2007) was 526.75 ton/month, which was reduced as 35.35 % compared without it. Also, during the rainy season (from Jun. to Sep. 2000 - 2007), when without vs. with rice straw mat, monthly sediment indicated 2,109.54 ton and 1,358.61 ton respectively. It showed about 35.60 % was reduced depending on rice straw mat. As shown in this study, if rice straw mat is used as a Best Management Practice (BMP) in the sloping fields, rainfall-driven sediment yield will be reduced effectively.

• Animal Bioscience
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• 제36권5호
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• pp.818-828
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• 2023

Objective: The purpose of this study was to analyze the effect of the hydrothermal pretreatment of anaerobic digestion sludge cake (ADSC) of cattle manure on the solubilization of organic matter and the methane yield to improve the anaerobic digestion efficiency of cattle manure collected from the sawdust pens of cattle. Methods: Anaerobic digestion sludge cake of cattle manure was thermally pretreated at 160℃, 180℃, 200℃, and 220℃ by a hydrothermal pressure reactor, and the biochemical methane potential of ADSC hydrolysate was analyzed. Methane yield recovered by the hydrothermal pretreatment of ADCS was estimated based on mass balance. Results: The chemical oxygen demand solubilization degree (COD_s) of the hydrothermal hydrolysate increased to 63.56%, 67.13%, 70.07%, and 66.14% at the hydrothermal reaction temperatures of 160℃, 180℃, 200℃, and 220℃, respectively. Considering the volatile solids content obtained after the hydrothermal pretreatment, the methane of 10.2 Nm³/ton-ADSC was recovered from ADSC of 1.0 ton, and methane yields of ADSC hydrolysate increased to 15.6, 18.0, 17.4, and 17.2 Nm³/ton-ADSC. Conclusion: Therefore, the optimal hydrothermal reaction temperature that yielded the maximum methane yield was 180℃ based on mass balance, and the methane yield from cattle manure containing sawdust was improved by the hydrothermal pretreatment of ADSC.