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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Journal of Agricultural and Forest Meteorology
Journal Basic Information
Journal DOI :
Korean Society of Agricultural and Forest Meteorology
Editor in Chief :
Volume & Issues
Volume 16, Issue 4 - Dec 2014
Volume 16, Issue 3 - Sep 2014
Volume 16, Issue 2 - Jun 2014
Volume 16, Issue 1 - Mar 2014
Selecting the target year
Effects of Geological Structure and Tree Density on the Forest Fire Patterns
Song, Hark-Soo ; Kwon, Oh Sung ; Lee, Sang-Hee ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 259~266
DOI : 10.5532/KJAFM.2014.16.4.259
Understanding the forest fire patterns is necessary to comprehend the stability of the forest ecosystems. Thus, researchers have suggested the simulation models to mimic the forest fire spread dynamics, which enables us to predict the forest damage in the scenarios that are difficult to be experimentally tested in laboratory scale. However, many of the models have the limitation that many of them did not consider the complicated environmental factors, such as fuel types, wind, and moisture. In this study, we suggested a simple model with the factors, especially, the geomorphological structure of the forest and two types of fuel. The two fuels correspond to susceptible tree and resistant tree with different probabilities of transferring fire. The trees were randomly distributed in simulation space at densities ranging from 0.5 (low) to 1.0 (high). The susceptible tree had higher value of the probability than the resistant tree. Based on the number of burnt trees, we then carried out the sensitivity analysis to quantify how the forest fire patterns are affected by the structure and tree density. We believe that our model can be a useful tool to explore forest fire spreading patterns.
Drought Resistance Assessment of Four Shrub Species Including Nandina Domestica for Extensive Green Roof
Shin, Chang-Seob ; Li, Hexi ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 267~273
DOI : 10.5532/KJAFM.2014.16.4.267
This study is to compare drought-resistance and to find the permanent wilting coefficient of Syringa Dilatata, Euonymus Japonica, Ligustrum Obtusifolium, Nandina Domestica, which are commonly used for rooftop garden due to their relatively strong drought resistance To compare the drought resistance precipitation was blocked from June 4, 2013 to July 20, 2013. During this time, the relative water content, specific electrical conductance, and water potential were measured every seven days and permanent wilting coefficients were investigated. Two days after precipitation was blocked, the relative water content in leaves were measured as follows: Ligustrum Obtusifolium 91.3%, Syringa Dilatata 92.9%, Nandina Domestica 91.2%, and Euonymus Japonica 90.1% respectively. After 28 days, relative water contents of leaves were reduced greatly 60.2% for Ligustrum Obtusifolium and 67.8% for Syringa Dilatata, but Nandina Domestica and Euonymus Japonica's reduced to 80.1% and 81.7% respectively. Permanent wilting coefficient was Ligustrum Obtusifolium 3.1%, Syringa Dilatata 2.1%, Nandina Domestica 1.6% and Euonymus Japonica 0.7%. In other words, the above four tree species are strong in drought resistance and Euonymus Japonica's drought resistance is the strongest while Nandina Domestica, Syringa Dilatata, Ligustrum Obtusifolium follow in that order.
Examining Impact of Weather Factors on Apple Yield
Kim, Mi Ri ; Kim, Seung Gyu ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 274~284
DOI : 10.5532/KJAFM.2014.16.4.274
Crops and varieties are mostly affected by temperature, the amount of precipitation, and duration of sunshine. This study aims to identify the weather factors that directly influence to apple yield among the series of daily measured weather variables during growing seasons. In order to identify them, 1) a priori natural scientific knowledge with respect to the growth stage of apples and 2) pure statistical approaches to minimize bias due to the subject selection of variables are considered. Each result estimated by the Panel regression using fixed/random effect models is evaluated through suitability (i.e., Akaike information criterion and Bayesian information criterion) and predictability (i.e., mean absolute error, root mean square error, mean absolute percentage). The Panel data of apple yield and weather factors are collected from fifteen major producing areas of apples from 2006 to 2013 in Korea for the case study. The result shows that variable selection using factor analysis, which is one of the statistical approaches applied in the analysis, increases predictability and suitability most. It may imply that all the weather factors are important to predict apple yield if statistical problems, such as multicollinearity and lower degree of freedom due to too many explanatory variables used in the regression, can be controlled effectively. This may be because whole growth stages, such as germination, florescence, fruit setting, fatting, ripening, coloring, and harvesting, are affected by weather.
Differences on Growth, Photosynthesis and Pigment Contents of Open-pollinated Pinus densiflora Families Under Elevated Temperature and Drought
Kim, Gil Nam ; Han, Sim-Hee ; Park, Gwan Soo ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 285~296
DOI : 10.5532/KJAFM.2014.16.4.285
The impacts of high temperature and drought were studied on the seedlings of three families (superiorgangwon74, intermediate-gangwon77 and inferior-gangwon132) of P. densiflora which had been selected by the based on the growth indexes of 32-year-old. The seedlings were grown in controlled-environment growth chambers with combinations of four temperatures (
; based on the monthly average for 30 years in Korea) and two water conditions (control, drought). The growth performance, photosynthetic parameters and photosynthetic pigment contents were measured at every 30 days under four temperatures and drought condition, and the end of each treatment. The superior family showed higher relative diameter at root collar growth rate and the dry weight than intermediate and inferior family in all treatments. Under elevated temperature and drought condition, growth rate was decreased, and seedlings showed lower growth rate than that of control in three families under low temperature. Photosynthetic rate, stomatal conductance and transpiration rate of three families decreased with the increase of temperature and drought condition, and that of seedlings under low temperature was lower than control. But under elevated temperature and drought condition, water use efficiency increased in three families. Photosynthetic pigment contents of leaves decreased under the increase of temperature and drought condition, but chlorophyll a/b ratio increased with the increase of temperature and drought condition in three families. The superior family showed higher total chlorophyll content than intermediate and inferior family in all treatments. In conclusion, P. densiflora is under changed temperature and drought condition, growth was decreased, seedlings more affected in elevated temperature than that of decreased temperature. The increase in monthly average temperature in Korea of more than
, P. densiflora seedling growth in depending on region may decrease. In this study, the superior family(gangwon74) showed more excellent growth and physiological responses than intermediate (gangwon77) and inferior(gangwon132) family under changes temperature and drought.
Improving usage of the Korea Meteorological Administration's Digital Forecasts in Agriculture: III. Correction for Advection Effect on Determination of Daily Maximum Temperature Over Sloped Surfaces
Kim, Soo-Ock ; Yun, Jin I. ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 297~303
DOI : 10.5532/KJAFM.2014.16.4.297
The effect of solar irradiance has been used to estimate daily maximum temperature, which make it possible to reduce the error inherent to lapse-rate based elevation difference correction in mountainous terrain. Still, recent observations indicated that the effect of solar radiation would need correction for estimation of daily maximum temperature. It was attempted to examine what would cause the variability of solar irradiance effect in determination of daily maximum temperature under natural field conditions and to suggest improved methods for estimation of the temperature distribution over mountainous regions. Temperature at 1500 and the wind speed for 1100 to 1500 were obtained at 10 validation sites with various topographical features including slope and aspect within a mountainous
catchment for 2012-2013. Lapse-rate corrected temperature estimates on clear days were compared with these observations, which would represent the differential irradiance effect among sloped surfaces. Results indicated a negative correlation between the mean wind speed and the estimation error. A simple scheme was derived from relationship between wind speed and estimation error for daily temperature to correct the effect of solar radiation. This scheme was incorporated into an existing model to estimate daily maximum temperature based on the effect of solar radiation. At 10 validation sites on clear days, estimates of 1500 LST temperature with and without the correction scheme were compared. It was found that a substantial improvement was achieved when the correction scheme was applied in terms of bias correction as well as error size reduction at all sites.
An Improved Method for Phenology Model Parameterization Using Sequential Optimization
Yun, Kyungdahm ; Kim, Soo-Hyung ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 304~308
DOI : 10.5532/KJAFM.2014.16.4.304
Accurate prediction of peak bloom dates (PBD) of flowering cherry trees is critical for organizing local cherry festivals and other associated cultural and economic activities. A two-step phenology model is commonly used for predicting flowering time depending on local temperatures as a result of two consecutive steps followed by chill and heat accumulations. However, an extensive computation requirement for parameter estimation has been a limitation for its practical use. We propose a sequential parameterization method by exploiting previously unused records of development stages. With an extra constraint formed by heat accumulation between two intervening stages, each parameter can then be solved sequentially in much shorter time than the brute-force method. The result was found to be almost identical to the previous solution known for cherry trees (Prunus
yedoensis) in the Tidal Basin, Washington D.C.
Growth Modeling of Chinese Cabbage in an Alpine Area
Ahn, Jae-Hoon ; Kim, Ki-Deog ; Lee, Jeoung-Tae ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 309~315
DOI : 10.5532/KJAFM.2014.16.4.309
Summer cabbages in an alpine area are very sensitive to the fluctuations in supply and demand. Yield variability due to weather conditions dictates the market fluctuations of cabbage price. This study reports an empirical relationship based on weather conditions to estimate the growth and harvestable biomass of cabbages, factors that are critical for supply of summer cabbages. Based on experimental results testing sowing date effects over the two years from 1997 to 1998, a logistic equation was parameterized to predict leaf area expansion of summer cabbages. This logistic model for leaf area expansion was then combined with an empirical allometric relationship to predict total biomass. The final equation for estimating fresh weight accumulation of Chinese cabbage is given by:
Where PHU is potential heat units (
). The model performance was tested using weather data from 2003 to 2006 to predict fresh harvestable biomass. Overall the model performance was satisfactory with the correlation efficient ranging between 0.89 and 0.94 for each year.
Spatiotemporal Assessment of the Late Marginal Heading Date of Rice using Climate Normal Data in Korea
Lee, Dongjun ; Kim, Junhwan ; Kim, Kwang Soo ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 316~326
DOI : 10.5532/KJAFM.2014.16.4.316
Determination of the late marginal heading date (LMHD), which would allow estimation of the late marginal seeding date and the late marginal transplanting date, would help identification of potential double cropping areas and, as a result, establishment of cropping systems. The objective of this study was to determine the LMHD at 51 sites in Korea. For these sites, weather data were obtained from 1971 to 2000 and from 1981 to 2010, which represent past and current normal climate conditions, respectively. To examine crop productivity on the LMHD, climatic yield potential (CYP) was determined to represent the potential yield under a given climate condition. The LMHD was calculated using accumulated temperature for 40 days with threshold values of
. The value of CYP on a given LMHD was determined using mean temperature and sunshine duration for 40 days from the LMHD. The value of CYP on the LMHD was divided by the maximum value of CYP (CYPmax) in a season to represent the relative yield on the LMHD compared with the potential yield in the season. Our results indicated that the LMHD was delayed at most sites under current normal conditions compared with past conditions. Spatial variation of the LMHD differed by the threshold temperature. Overall, the minimum value of CYP/CYPmax was 81.8% under all of given conditions. In most cases, the value of CYP/CYPmax was >90%, which suggested that yield could be comparable to the potential yield even though heading would have occurred on the LMHD. When the LMHD could be scheduled later without considerable reduction in yield, the late marginal transplanting date could also be delayed accordingly, which would facilitate doublecropping in many areas in Korea. Yield could be affected by sudden change of temperature during a grain filling period. Yet, CYP was calculated using mean temperature and sunshine duration for 40 days after heading. Thus, the value of CYP/CYPmax may not represent actual yield potential due to change of the LMHD, which suggested that further study would be merited to take into account the effect of weather events during grain filling periods on yield using crop growth model and field experiments.
Development of Local Stem Volume Table for Pinus densiflora S. et Z. Using Tree Stem Taper Model
Kang, Jin-Taek ; Son, Yeong-Mo ; Kim, So-Won ; Lee, Sun-Jeoung ; Park, Hyun ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 327~335
DOI : 10.5532/KJAFM.2014.16.4.327
Current volume tables might underestimate or overestimate the volumes of individual trees in a specific region because the tables were made using the data from broad regions within South Korea. Therefore, to solve this problem, this study was conducted to develop local stem volume tables reflecting the local growth pattern and properties using stem taper equations in the regions of Hongcheon and Yeongju. We developed the local stem volume table for Pinus densiflora, which is the widely planted species in South Korea. To derive the most suitable taper equation for estimating the stem volume of region, three models of Max & Burkhart, Kozak and Parresol et al. were applied and their fitness were statistically analyzed by using the Fitness Index, Bias, and Standard Error of Bias. The result showed that there is a significant difference among the three models, and the Fitness Index of the Kozak model was highest compared to the other models. Therefore, the Kozak model was chosen for generating stem taper equation and stem volume tables for P. densiflora. The result from the developed stem volume tables of each region was compared to the current stem volume tables with driven by the data of tree growth obtained throughout the nation. The result showed that there is a significant difference (0.000<
) in two regions, Hongcheon and Yeongju, and also there is a significant difference (0.000<
) between the two regions.
Estimation of the Greenhouse Gas Inventory on Forest Land at Provincial Level
Kim, Kyeong Nam ; Lee, Sun Jeoung ; Kim, Raehyun ; Son, Yeong Mo ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 336~342
DOI : 10.5532/KJAFM.2014.16.4.336
This study was conducted to estimate of the greenhouse gas inventory on forest land at provincial level. The greenhouse gas emissions are calculated according to the K-MRV guidance. We collected activity data from statistical yearbook of forestry and used default emission factors. The annual total
emission in forest land was -58,711Gg
and the annual
emission in loss such as fellings, fuelwood and fire was 19,896Gg
in 2011. The results showed the removals of carbon dioxide in the forest land, it's amount was -38,815Gg
in 2011. Annual net
removal of local forest was highest in Kangwon province in 2011. Our study did not use the many statistics due to exclusion of double counting. There are need complementary activity data and emission factors, and then we will find a way to calculate the greenhouse gas emissions/removals in the near future.
A Simple Emergence Model of Southern Type Garlic Based on Temperature
Moon, K.H. ; Choi, K.S. ; Son, I.C. ; Song, E.Y. ; Oh, S. ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 343~348
DOI : 10.5532/KJAFM.2014.16.4.343
We developed a simple model to predict emergence time and emergence rate of southern type garlic using the daily mean temperature. Emergence rate of garlic was decreased and emergence time was delayed on higher temperature than optimum temperature of
. In the model, firstly daily emergence rate was calculated using a beta function to input daily mean temperature, then the percentage of garlic emergence was calculated using a nonlinear model with accumulated emergence rate. The model was good to describe the experimental data of growth cabinet. Also it can explain well the experimental data using temperature gradient tunnel, designed for verification of model performance. But there are 5 days of deviation between estimated and measured time of garlic emergence on the field experiment. More research is needed to develop an advanced model considering other factors, such as soil moisture.
Impact of Elevated Temperature in Growing Season on Growth and Fruit Quality of Red Pepper (Capsicum annuum L.)
Song, Eun Young ; Moon, Kyung Hwan ; Son, In Chang ; Kim, Chun Hwan ; Lim, Chan Kyu ; Son, Daniel ; Oh, Soonja ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 349~358
DOI : 10.5532/KJAFM.2014.16.4.349
This study was conducted to determine the impact of elevated temperature in growing season on the growth and fruit quality of red pepper (Capsicum annuum L.) by cultivating pepper in the temperature gradient tunnels. Plant height, stem diameter, leaf number and total leaf area, fresh weight and dry weight increased at ambient
temperature, whereas each leaf area decreased as temperature increased. The plants grown under ambient
temperature showed the greatest number of flower and fruit. Fruit weight, fruit length and fruit diameter decreased as the temperature increasing gradually. Total fruit number, total fruit weight and total dry fruit weight was the highest at ambient
temperature. Major free sugars of red pepper fruit were fructose and glucose. Free sugar content of red pepper according to the differences in harvesting times and in growth temperature showed a little differences. The yield of red pepper fruit at ambient
temperature increased by 13% compared with the control. However, the yield of red pepper fruit at ambient
temperature decreased by 20% as compared to control. Non-marketable fruits (diseased fruit, malformed fruit and small sized fruit) increased as the temperature rised.
Drought Index Development for Agricultural Drought Monitoring in a Catchment
Kim, Dae-Jun ; Moon, Kyung-Hwan ; Yun, Jin I. ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 359~367
DOI : 10.5532/KJAFM.2014.16.4.359
Drought index can be used to implement an early warning system for drought and to operate a drought monitoring service. In this study, an approach was examined to determine agricultural drought index (ADI) at high spatial resolution, e.g., 270 m. The value of ADI was calculated based on soil water balance between supply and demand of water. Water supply is calculated by the cumulative effective precipitation with the application of the weight to the precipitation from two months ago. Water demand is derived from the actual evapotranspiration, which was calculated applying a crop coefficient to the reference evapotranspiration. The amount of surface runoff on a given soil type was also used to calculate soil residual moisture. Presence of drought was determined based on the probability distribution in the given area. In order to assess the reliability of this index, the amount of residual moisture, which represents severity of drought, was compared with measurements of soil moisture at three experimental between July 2012 and December 2013. As a result, the ADI had greater correlation with measured soil moisture compared with the standardized precipitation index, which suggested that the ADI would be useful for drought warning services.
Research Status and Future Subjects to Predict Pest Occurrences in Agricultural Ecosystems Under Climate Change
Jung, Jong-Kook ; Lee, Hyoseok ; Lee, Joon-Ho ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 368~383
DOI : 10.5532/KJAFM.2014.16.4.368
Climate change is expected to affect population density, phenology, distribution, morphological traits, reproduction and genetics of insects, and even in the extinction of insects. To develop novel research subjects for predicting climate change effect, basic information about biological and ecological data on insect species should be compiled and reviewed. For this reason, this study was conducted to collect the biological information on insect pests that are essential for predicting potential damage caused by insect pests in future environment. In addition, we compared domestic and foreign research trends regarding climate change effect and suggested future research subjects. Domestic researchers were rather narrow in the subject, and were mostly conducted based on short-term monitoring data to determine relationship between insects and environmental variables. On the other hand, foreign researches studied on various subjects to analyze the effect of climate change, such as changes in distribution of insect using long-term monitoring data or their prediction using population parameters and models, and monitoring of the change of the insect community structure. To determine change of the phenology, distribution, overwintering characteristics, and genetic structures of insects under climate change through development of monitoring technique, in conclusion, further researches are needed. Also, development of population models for major or potential pests is important for prediction of climate change effects.
Change of Climatic Productivity Index for Rice under Recent Climate Change in Korea
Shim, Kyo-Moon ; Kim, Yong-Seok ; Jung, Myung-Pyo ; Choi, In-Tae ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 384~388
DOI : 10.5532/KJAFM.2014.16.4.384
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
Implementation of a Weather Hazard Warning System at a Catchment Scale
Park, Ju Hyun ; Kim, Seong Kee ; Shin, Yong Soon ; Ahn, Mun Il ; Han, Yong Kyu ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 389~395
DOI : 10.5532/KJAFM.2014.16.4.389
This technical note describes about the base stages of technology implementation for establishing "Early Warning System for Weather Hazard Management in Climate-smart Agriculture" to national onsite service. First of all, a special weather report service at catchment was represented sequential risk of 810 units of catchment by spatial statistical methods to existing 150 counties units special weather report released in KMA. The second, chronic hazard alarm service based on daily data of 76 Synoptic stations was monitor about 810 Catchment of mid-long term lapse weather and represented as a relative risk index chronic hazard risk of this time in preparation for the climatological normal conditions in the same period. Finally, we establish the foundation for delivering individually calculated field specific in hazard risk about volunteer farmer of early warning service demonstration area in seomjin downstream watershed. These three types of information were built a near real-time map service on the VWORLD background map of Ministry of Land as superposed layers nationwide catchment and demonstration areas within the farm unit weather hazard.
Recent Trends in Blooming Dates of Spring Flowers and the Observed Disturbance in 2014
Lee, Ho-Seung ; Kim, Jin-Hee ; Yun, Jin I. ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 396~402
DOI : 10.5532/KJAFM.2014.16.4.396
The spring season in Korea features a dynamic landscape with a variety of flowers such as magnolias, azaleas, forsythias, cherry blossoms and royal azaleas flowering sequentially one after another. However, the narrowing of south-north differences in flowering dates and those among the flower species was observed in 2014, taking a toll on economic and shared communal values of seasonal landscape. This study was carried out to determine whether the 2014 incidence is an outlier or a mega trend in spring phenology. Data on flowering dates of forsythias and cherry blossoms, two typical spring flower species, as observed for the recent 60 years in 6 weather stations of Korea Meteorological Administration (KMA) indicate that the difference spanning the flowering date of forsythias, the flower blooming earlier in spring, and that of cherry blossoms that flower later than forsythias was 30 days at the longest and 14 days on an average in the climatological normal year for the period 1951-1980, comparing with the period 1981-2010 when the difference narrowed to 21 days at the longest and 11 days on an average. The year 2014 in particular saw the gap further narrowing down to 7 days, making it possible to see forsythias and cherry blossoms blooming at the same time in the same location. 'Cherry blossom front' took 20 days in traveling from Busan, the earliest flowering station, to Incheon, the latest flowering station, in the case of the 1951-1980 normal year, while 16 days for the 1981-2010 and 6 days for 2014 were observed. The delay in flowering date of forsythias for each time period was 20, 17, and 12 days, respectively. It is presumed that the recent climate change pattern in the Korean Peninsula as indicated by rapid temperature hikes in late spring contrastive to slow temperature rise in early spring immediately after dormancy release brought forward the flowering date of cherry blossoms which comes later than forsythias which flowers early in spring. Thermal time based heating requirements for flowering of 2 species were estimated by analyzing the 60 year data at the 6 locations and used to predict flowering date in 2014. The root mean square error for the prediction was within 2 days from the observed flowering dates in both species at all 6 locations, showing a feasibility of thermal time as a prognostic tool.
Agrometeorological Early Warning System: A Service Infrastructure for Climate-Smart Agriculture
Yun, Jin I. ;
Korean Journal of Agricultural and Forest Meteorology, volume 16, issue 4, 2014, Pages 403~417
DOI : 10.5532/KJAFM.2014.16.4.403
Increased frequency of climate extremes is another face of climate change confronted by humans, resulting in catastrophic losses in agriculture. While climate extremes take place on many scales, impacts are experienced locally and mitigation tools are a function of local conditions. To address this, agrometeorological early warning systems must be place and location based, incorporating the climate, crop and land attributes at the appropriate scale. Existing services often lack site-specific information on adverse weather and countermeasures relevant to farming activities. Warnings on chronic long term effects of adverse weather or combined effects of two or more weather elements are seldom provided, either. This lecture discusses a field-specific early warning system implemented on a catchment scale agrometeorological service, by which volunteer farmers are provided with face-to-face disaster warnings along with relevant countermeasures. The products are based on core techniques such as scaling down of weather information to a field level and the crop specific risk assessment. Likelihood of a disaster is evaluated by the relative position of current risk on the standardized normal distribution from climatological normal year prepared for 840 catchments in South Korea. A validation study has begun with a 4-year plan for implementing an operational service in Seomjin River Basin, which accommodates over 60,000 farms and orchards. Diverse experiences obtained through this study will certainly be useful in planning and developing the nation-wide disaster early warning system for agricultural sector.