• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.113-120
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• 2008

The increase in average air temperature over the past 100 years in northern Asia including Korea is the greatest (about ${1.5}^{\circ}C$) among the various regions of the world. Considering a further warming projected by the IPCC, fluctuations of agro-climatic indices under climate change must precede an evaluation of vulnerability. The purpose of this study is to analyze how climate changes represented by global warming have altered agro-climatic indices in Korea over various time scales. Drought index during the rice-transplanting period of 15 May to 5 June has changed toward the favorable with recently increased precipitation in the Taebaek Alpine and Semi-Alpine Zone, and Yeongnam Basin and Inland Zone. The frequency of low temperature occurrence below $13^{\circ}C$ during the rice transplanting has decreased, while climatic production index (CPI) has fallen because of the decreased sunshine hour and increased temperature during the rice ripening period. We therefore concluded that the recent change of climate conditions was against the rice productivity in Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.108-125
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• 2015

The agro-climatic index is one of the ways to assess the climate resources of particular agricultural areas on the prospect of agricultural production; it can be a key indicator of agricultural productivity by providing the basic information required for the implementation of different and various farming techniques and practicalities to estimate the growth and yield of crops from the climate resources such as air temperature, solar radiation, and precipitation. However, the agro-climate index can always be changed since the index is not the absolute. Recently, many studies which consider uncertainty of future climate change have been actively conducted using multi-model ensemble (MME) approach by developing and improving dynamic and statistical downscaling of Global Climate Model (GCM) output. In this study, the agro-climatic index of Korean Peninsula, such as growing degree day based on $5^{\circ}C$, plant period based on $5^{\circ}C$, crop period based on $10^{\circ}C$, and frost free day were calculated for assessment of the spatio-temporal variations and uncertainties of the indices according to climate change; the downscaled historical (1976-2005) and near future (2011-2040) RCP climate sceneries of AR5 were applied to the calculation of the index. The result showed four agro-climatic indices calculated by nine individual GCMs as well as MME agreed with agro-climatic indices which were calculated by the observed data. It was confirmed that MME, as well as each individual GCM emulated well on past climate in the four major Rivers of South Korea (Han, Nakdong, Geum, and Seumjin and Yeoungsan). However, spatial downscaling still needs further improvement since the agro-climatic indices of some individual GCMs showed different variations with the observed indices at the change of spatial distribution of the four Rivers. The four agro-climatic indices of the Korean Peninsula were expected to increase in nine individual GCMs and MME in future climate scenarios. The differences and uncertainties of the agro-climatic indices have not been reduced on the unlimited coupling of multi-model ensembles. Further research is still required although the differences started to improve when combining of three or four individual GCMs in the study. The agro-climatic indices which were derived and evaluated in the study will be the baseline for the assessment of agro-climatic abnormal indices and agro-productivity indices of the next research work.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.384-388
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• 2014

Air temperature has increased, while sunshine hour has decreased during the grain filling period of most rice cultivars (August to September) during the past 12 years from 2001 through 2012 in Korea. Climatic Productivity Index (CPI) has fallen because of the decreased sunshine hour and increased air temperature during the grain filling period, and the degree of reduction was greater with earlier heading. For stable rice production, we will need to delay the heading of rice as a cultivation measure against the future climatic trend. Grain yield showed no significant trend for past 12 years. However, the year to year change in grain yield showed a similliar pattern with that of CPI. Especially, a linear function relating rice yield to CPI explained approximately 63% of variation in grain yield with the heading date of August $11^{th}$ period.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.207-209
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• 2003

Quantifying crop production is one of the most important applications of remote sensing in which the temporal and up-to-date data can play very important role in avoiding any immediate insufficiency in agricultural production. A combination of climatic data and biophysical parameters derived from Landsat7 ETM+ was used to develop a mathematical model for wheat yield forecast in different geographically wide Wheat growing districts in Egypt. Leaf Area Index (LAI) and fraction of Absorbed Photosynthetically Active Radiation (fAPAR) with temperature were used in the modeling. The model includes three sub-models representing the correlation between the reported yield and each individual variable. Simulation results using district statistics showed high accuracy of the derived correlations to estimate wheat production with a percentage standard error (%S.E.) of 1.5% in El- Qualyobia district and average (%S.E.) of 7% for the whole wheat areas.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.107-114
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• 1999

The large-scale distribution of crops Is usually determined by climate. We present the results of a climate-crop prediction based on spatial bio-physical process model approach, implemented in a GIS (Geographic Information System) environment using several regional and global agriculture-environmental databases. The model utilizes daily climate data like temperature, rainfall, solar radiation being generated stocastically by in-built model weather generator to determine the daily biomass and finally the crop yield. Crops are characterized by their specific growing period requirements, photosynthesis, respiration properties and harvesting index properties. Temperature and radiation during the growing period controls the development of each crop. The model simulates geographic/spatial distribution of climate by which a crop-growing belt can also be determined. The model takes both irrigated and non-irrigated area crop productivity into account and the potential increase in productivity by the technical means like mechanization is not considered. All the management input given at the base year 1995 was kept same for the next twenty-year changes until 2015. The simulated distributions of crops under current climatic conditions coincide largely with the current agricultural or specific crop growing regions. Simulation with assumed weather generated derived climate change scenario illustrate changes in the agricultural potential. There are large regional differences in the response across the country. The north-south and east-west regions responded differently with projected climate changes with increased and decreased productivity depending upon the crops and scenarios separately. When water was limiting or facilitating as non-irrigated and irrigated area crop-production effects of temperature rise and higher $CO_2$ levels were different depending on the crops and accordingly their production. Rise in temperature led to yield reduction in case of maize and rice whereas a gain was observed for wheat crop, doubled $CO_2$ concentration enhanced yield for all crops and their several combinations behaved differently with increase or decrease in yields. Finally, with this spatial modeling approach we succeeded in quantifying the crop productivity which may bring regional disparities under the different climatic scenarios where one region may become better off and the other may go worse off.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.442-450
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• 2015

Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of $28.4^{\circ}C$ and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of $-4.0^{\circ}C$ and a wind-chill temperature of $-6.2^{\circ}C$. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated ($r{\geq}0.71$; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated ($r{\leq}-0.74$; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions.

• International Journal of Industrial Entomology and Biomaterials
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• v.47 no.1
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• pp.34-43
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• 2023

The eighteen (18) F₁ hybrid combinations were tested to identify potential combinations adaptable to type 1 climatic conditions in the Philippines. The six (6) bivoltine purelines (DMMMSU 108, DMMMSU 109, DMMMSU 110, DMMMSU 111, DMMMSU 113, and DMMMSU 119); and three (3) multivoltine purelines (DMMMSU 1000, DMMMSU 1007, and DMMMSU 1014), were crossed (multivoltine x bivoltine) in a mating plan. These were arranged in a Completely Randomized Design (CRD), replicated three times, and analyzed using Analysis of Variance (ANOVA). A test of significance was done using ANOVA across years and Tukey's Honest Significant Difference Test (HSD). The multiple trait evaluation index (EI) method was also used in the identification of potential F₁ hybrids. Three major phases were done: (1) parental rearing of multivoltine and bivoltine pure lines for breed multiplication; (2) hybridization process; and (3) evaluation of F₁ hybrids. Rearing evaluations were conducted for three consecutive years. Based from the three evaluations, 10 potential crosses were identified: DMMMSU MV-12, DMMMSU MV-11, DMMMSU MV-13, DMMMSU MV-16, DMMMSU MV-07, DMMMSU MV-14, DMMMSU MV-05, DMMMSU MV-09, DMMMSU MV-03, and DMMSU MV-10. The topmost combinations with the best economic and commercial characters and are consistently adaptable during two (2) cropping seasons were DMMMSU MV-07, DMMMSU MV-12, DMMMSU MV-05, DMMMSU MV-09 and DMMMSU MV-11. These newly-identified F₁ hybrids are considered potential breeds that could improve cocoon production.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.1
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• pp.145-159
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• 2019

A good number of drought indices have been introduced and applied in different regions for monitoring drought conditions, but some of those are region-specific and have limitations for use under other climatic conditions because of the inherently complex characteristics of drought phenomenon. Standardized Precipitation Index (SPI) indices are widely used all over the world, including Bangladesh. Although newly developed, studies have demonstrated The Effective Drought Index (EDI) to perform better compared to SPIs in some areas. This research examined the performance of EDI to the SPI for detecting drought events throughout 35 years (1981 to 2015) in Bangladesh. Rainfall data from 27 meteorological stations across Bangladesh were used to calculate the EDI and SPI values. Results suggest that the EDI can detect historical records of actual events better than SPIs. Moreover, EDI is more efficient in assessing both short and long-term droughts than SPIs. Results also indicate that SPI3 and the EDI indices have a better capability of detecting drought events in Bangladesh compared to other SPIs; however, SPI1 produced erroneous estimates. Therefore, EDI is found to be more responsive to drought conditions and can capture the real essence of the drought situation in Bangladesh. Outcomes from this study bear policy implications on mitigation measures to minimize the loss of agricultural production in drought-prone areas. Information on severity level and persistence of drought conditions will be instrumental for resource managers to allocate scarce resources optimally.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.1
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• pp.11-22
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• 2010

According to IPCC 4th Assessment Report, concentration of carbon dioxide has been increasing by 30% since Industrial Revolution. Most of IPCC $CO_2$ emission scenarios estimate that the concentration will reach up to double of its present level within 100-year if the current tendency continues. The global warming has resulted in the agro-climate change over the Korean Peninsula as well. Accordingly, it is necessary to understand the future agro-climate induced by the increase of greenhouse gases in terms of the agro-climatic indices in the Korean peninsula. In this study, the future climate is simulated by an atmosphere/ocean/land surface/sea ice coupled general circulation climate model, Pusan National University Coupled General Circulation Model(hereafter, PNU CGCM), and by a regional weather prediction model, Weather Research and Forecasting Model(hereafter, WRF) for the purpose of a dynamical downscaling. The changes of the vegetable period and the crop growth period, defined as the total number of days of a year exceeding daily mean temperature of 5 and 10, respectively, have been analyzed. Our results estimate that the beginning date of vegetable and crop growth periods get earlier by 3.7 and 17 days, respectively, in spring under the $CO_2$-doubled climate. In most of the Korean peninsula, the predicted frost days in spring decrease by 10 days. Climatic production index (CPI), which closely represent the productivity of rice, tends to increase in the double $CO_2$ climate. Thus, it is suggested that the future $CO_2$ doubled climate might be favorable for crops due to the decrease of frost days in spring, and increased temperature and insolation during the heading date as we expect from the increased CPI.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.218-222
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• 2006

This experiment was conducted to investigate the effects of climatic factors varied due to the type of plastic house, cultural season and location in the house on the growth of cucumber plants grown by nutrient solution. There were two growing periods, summer culture and retarding culture, two types of plastic houses, 1-2W type house and post-less house. Air temperature, relative humidity and amount of solar radiation in the plastic houses were measured. Also, dry weight of leaves and stems, plant height, number of leaves per plant, leaf area per plant and fresh weight of fruits per plant were observed. Plant growth analysis were conducted and interrelationships between climatic factors and physiological characteristics were investigated. The results were as follows. There were no differences between the type of plastic houses in the average air temperature and average relative humidity in the plastic house, but amount of solar radiation in 1-2W type house was significantly higher than that of postless house. Daily cumulative solar radiation were highest in southwest side of 1-2W type house and northwest side of postless house. Plant height and number of leaves per plant were higher in summer culture than retarding culture, while leaf area per plant was higher in retarding culture than summer culture. Relative growth rate (RGR) showed highly significantly positive correlations with net assimilation rate (WAR) and leaf area ratio (LAR). Contribution of NAR to RGR was much higher than that of LAR. Crop growth rate (CGR) showed highly significantly positive correlations with leaf area index (LAI). It appeared that increase of LAI was important to increase productivity of cucumber. Average daily air temperature for the whole growing period showed highly significantly positive correlations with RGR and NAR. Furthermore, cumulative solar radiation for the whole growing period in retarded culture showed significantly positive correlation with RGR and NAR.