• Journal of Korean Society for Geospatial Information Science
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• 제14권1호
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• pp.13-19
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• 2006

When investigating the damage of a forest fire, quite a few are depending on the naked eye observation. However, if the damage spreads to another area, it is easy to use the satellite images because it is hard to reach all the damaged areas on foot. From this research, we did a statistical interpretation of after fire using satellite image data to classify the damage on first and second factor analysis. As a result, it was more easier to classify the river's plants and ridges between rice fields that were in the forest fire damage area in the second observation then the first observation. Also, we could classify the area by areas that were damaged more or less using the second factor analysis. To verify this, we used the forest fire images collected from the satellite images and the actual survey data collected from spectral radiometer to see if these two datawere correlated and as a result we found out that they were highly involved.

• Hwankyungkyoyuk
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• 제23권4호
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• pp.82-95
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• 2010

The Water Environmental Education Program Using Streams(WEES) is developed to help the teachers increase their professionalism of incorporating a local environment into their inquiry teaching. The purpose of this study is inquiry about the 'Baig Cheon' stream with the perspective of environmental studies for WEES. Through these studies, we tried to get the background information in 'Baig Cheon' and profound insights into application of WEES. The 'Baig Cheon' was examined from the perspective of environmental studies through literature study, field study, and water quality monitoring. The results revealed the characteristics of the 'Baig Cheon' that ran across a rural area in terms of the watershed boundaries, water systems, and water usage. The changes to the water quality items were observed according to the spatial distribution at the measuring points across the watershed for six months from March to August, 2007. The results indicate that the water quality of the 'Baig Cheon' could well be affected not only by the natural and environmental conditions such as the geological features, but also by the human activities including the land uses in the surrounding roads, rice fields and farms and the water supply and usage. The inquiry of the 'Baig Cheon' from the perspective of environmental studies will hopefully make the education and inquiry process of WEES more meaningful and in-depth and contribute to providing better environmental education that properly reflects the nature of inquiry from the perspective of environmental studies.

• Korean Journal of Weed Science
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• 제14권2호
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• pp.112-119
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• 1994

The experiment was conducted to investigate the cause of the continous increase of Sagittaria trifolia dominance and it's effective control methods in the paddy rice fields. Early physilogical response of S. trifolia caused by sulfonylurea three herbicides resulted in growth cessation. However, the growth-ceased plant regrew after the certain period of time. Pyrazolate{4-[2, 4-dichloro benzoyl]-1, 3-dimethylpyrazol-5-yl-ptoluene sulphonate} could control S. trifolia until 6-7 leaf stages. The herbicidal activity of S. trifolia by pyrazolate was not related to the size of tuber and the amount of carbohydrate consumption in the tuber. The production of S. trifolia tubers inhibited more than 95% by the systematic treatment of pyrazosulfuron-ethyl{Ethyl-5-(4, 6-dimethoxy pyrimidin-2-yl carbomoyl sulfamoyl)-2-chloro-2', 6'-diethyl acetanilide}, cinosulfuron and pyrazolate after the first treatment of pyrazosulfuron-ethyl and pyrazolate.

• Journal of Ecology and Environment
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• 제29권4호
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• pp.331-335
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• 2006

We investigated the distribution of three anuran species, Three-striped pond frogs (Rana nigromaculata), Bullfrogs (Rana catesbeiana), and Narrow-mouthed toads (Kaloula borealis), in an administrative district, Haenam Gun, Junnam Province, Korea using volunteer call surveys. Twenty-eight volunteer call surveyors were assigned to each $2{\times}2km^2$ survey plot. Call surveys on whether the species are present or not were conducted for 5 minutes between 30 minutes after sunset and the midnight on rice fields and ponds from 10 April to 28 August in 2005. Depending on species, call surveys were carried out at seven to 28 plots with average 8.4 to 10.7 visits per the plot. We calculated the detection probabilities and occupancy rates of the three species using four models with three covariates: temperature, humidity, and the amount of water at the habitat. The model average detection probabilities of three anuran species of R. nigromaculata, R. catesbeiana, and K. borealis were 0.53, 0.74, and 0.41 respectively, and the site occupancy rates of them were 0.93, 0.94, and 0.86 respectively. Our results indicate that R. nigromaculata, R. catesbeiana, and K. borealis are common in Haenam Gun.

• Proceedings of the Korean Society of Crop Science Conference
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• 한국작물학회 1998년도 21세기 한반도 농업전망과 대책(한국작물학회.한국육종학회 공동주관 심포지움 회보)
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• pp.134-158
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• 1998

The objectives of this article are to identify the current status of agricultural infrastructure in North Korea and to suggest some cooperation measures among South and North Koreas and international agencies in order to develop the North Korea's agricultural infrastructure. The area of cultivated land in North Korea is 1,992 thousand ha (paddy field: 585 thousand ha: upland: 1,407 thousand ha) in 1997. Major water use facilities in North Korea are 1,900 reservoirs (included 100 big dams), 36,400 irrigation pumping stations, 1,600 drainage pumping stations, and 14'a,000 wells. In addition, there is 'two thousand Ri canal construction project' linking the rivers of Aprok, Daeryong, Daedong, Jaeryong, and Yesong. The unit of paddy land consolidation is about 1 ha which is regarded as rational for agricultural mechanization. The project of 'Darak' upland construction to create small size farmland, which has been carried out since 1976 has been unsuccessful due to the shortage of construction equipment. The area of farmland created by reclamation by 1995 is only 75 thousand ha although the potential project area is at)out 320 thousand ha along the western coast. It is due to the fact that civil engineering technologies and equipments are old and investment funds are insufficient. These are a few suggested areas of cooperation among South and North Korea and international agencies in order to improve North Korea's agricultural infrastructure : i) see land reclamation and land consolidation projects to increase paddy fields for rice production; ii) rehabilitation project in farm land areas devastated by flood; and iii) agricultural water development project which including diagnosing and rehabilitating irrigation and drainage facilities.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.408-417
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• 2016

Purpose: Yield monitoring systems are an essential component of precision agriculture. They indicate the spatial variability of crop yield in fields, and have become an important factor in modern harvesters. The objective of this paper was to review research trends related to yield monitoring sensors for grain crops. Methods: The literature was reviewed for research on the major sensing components of grain yield monitoring systems. These major components included grain flow sensors, moisture content sensors, and cutting width sensors. Sensors were classified by sensing principle and type, and their performance was also reviewed. Results: The main targeted harvesting grain crops were rice, wheat, corn, barley, and grain sorghum. Grain flow sensors were classified into mass flow and volume flow methods. Mass flow sensors were mounted primarily at the clean grain elevator head or under the grain tank, and volume flow sensors were mounted at the head or in the middle of the elevator. Mass flow methods used weighing, force impact, and radiometric approaches, some of which resulted in measurement error levels lower than 5% ($R^2=0.99$). Volume flow methods included paddle wheel type and optical type, and in the best cases produced error levels lower than 3%. Grain moisture content sensing was in many cases achieved using capacitive modules. In some cases, errors were lower than 1%. Cutting width was measured by ultrasonic distance sensors mounted at both sides of the header dividers, and the errors were in some cases lower than 5%. Conclusions: The design and fabrication of an integrated yield monitoring system for a target crop would be affected by the selection of a sensing approach, as well as the layout and mounting of the sensors. For accurate estimation of yield, signal processing and correction measures should be also implemented.

• Journal of the Korean Society of Food Culture
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• 제2권1호
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• pp.81-92
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• 1987

This treatise deals with chronic state of famine and exploitation of famine relief food in the later half of Chosun Period and especially in relation with socio-economic changes. There with the impact of socio-economic factors on the chronic state of famine and exploitation of famine relief food is studied mainly with a literary approach. The influential factors which lead to the chronic state of famine were not only climatic restrictions such as flood and drought but socio-economic factors such as foreign invasion (Japanease invasion and Ching's invasion), frequent breaking out of revolt and technological development of agriculture (rice transplantation). And disorder of land system and cultivation of cash crops by the richer peasantry, lowering the economic status of the poorer peasantry who were a major constituents of the population, aggravated the famine state. Because the poorer peasantry were under the shortage of food, they had to seek something edible in the fields and mountains. In this process various kinds of famine relief foods were exploited by the poorer peasantry. The majority of famine relief foods were wild vegetables. Consequently the Chronic state of famine was a cause to introduce various edible wild vegetables into Korean food, which influenced modern vegetarian food habits and firmed the Korean's favorite taste to be hot and salty. These wild vegetables couldn't have a marvelous effect on the relief of starved people. Potatoes and sweet potatoes, which were newly introduced foreign crops, were encouraged to be cultivated for famine relief. But these tubers, unable to be staple food, didn't contribute to an increase in population.

• Korean Journal of Environmental Agriculture
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• 제40권3호
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• pp.149-160
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• 2021

BACKGROUND: Concerns have been raised about the impact of recent high concentrations of fine dust on human health. Ammonia(NH₃) reacts with sulfur oxides and nitrogen compounds in the atmosphere to form ultrafine ammonium sulfate and ammonium nitrate (PM2.5). There is a growing need for accurate estimates of the amount of ammonia emitted during agricultural production. Therefore, in this study, ammonia emissions generated from the cultivation of leafy perilla in plastic houses were determined. METHODS AND RESULTS: Cow manure compost, swine manure compost, and poultry manure compost each at 34.6 ton ha^-1, the amount commonly used by farmers in the field, was sprayed on the soil surface. Just after spraying cow manure compost, swine manure compost, and poultry manure compost, the ammonia was periodically measured and analyzed to be 22.5 kg ha^-1, 22.8 kg ha^-1, and 85.2 kg ha^-1, respectively. The emission factors were estimated at 70.0 kg-NH₃ ton-N, 62.8 kg-NH₃ ton-N, and 234.1 kg-NH₃ ton-N, respectively. Most ammonia was released in the two weeks after application of the compost and then the amount released gradually decreased. CONCLUSION: Therefore, it is necessary to improve the emission factor through a study on the estimation of ammonia emission by type of livestock manure and major farming types such as rice fields and uplands, and to update data on the production, distribution, and sales of livestock manure.

• Journal of Korean Society of Rural Planning
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• 제24권4호
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• pp.99-119
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• 2018

Unit load factor, which is used for the quantification of non-point pollution in watersheds, has the limitation that it does not reflect spatial characteristics of soil, topography and temporal change due to the interannual or seasonal variability of precipitation. Therefore, we developed the method to estimate a watershed-scale non-point pollutant load using seasonal forecast data that forecast changes of precipitation up to 6 months from present time for watershed-scale water quality management. To establish a preemptive countermeasure against non-point pollution sources, it is possible to consider the unstructured management plan which is possible over several months timescale. Notably, it is possible to apply various management methods such as control of sowing and irrigation timing, control of irrigation through water management, and control of fertilizer through fertilization management. In this study, APEX-Paddy model, which can consider the farming method in field scale, was applied to evaluate the applicability of seasonal forecast data. It was confirmed that the rainfall amount during the growing season is an essential factor in the non-point pollution pollutant load. The APEX-Paddy model for quantifying non-point pollution according to various farming methods in paddy fields simulated similarly the annual variation tendency of TN and TP pollutant loads in rice paddies but showed a tendency to underestimate load quantitatively.

• Korean Journal of Agricultural Science
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• 제45권4호
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• pp.575-582
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• 2018

Bacterial fruit blotch (BFB) caused by Acidovorax citrulli is a devastating disease found in many cucurbits cultivation fields. The genetic diversity for 29 strains of A. citrulli collected from various cucurbits in South Korea was determined by DNA fingerprinting with a pathogenicity test, multi locus analysis, Rep-PCR (repetitive sequence polymerase chain reaction), and URP (universal rice primers) PCR bands. Two distinct groups (Korean Clonal Complex, KCC1 and KCC2) in the population were identified based on group specific genetic variation in the multi locus phylogeny using six conserved loci and showed a very high similarity with DNA sequences for representative foreign groups [the group I (CC1-1 type) and the group II (CC2-5 type)] widely distributed worldwide, respectively. Additionally, in the case of phaC, a new genotype was found within each Korean group. The KCC1 was more heterogeneous compared to the KCC2. The KCC1 recovered mainly from melons and watermelons (ratio of 6 : 3) and 15 of the 20 KCC2 strains recovered from watermelons were dominant in the pathogen population. Accordingly, this study found that two distinct groups of differentiated A. citrulli exist in South Korea, genetically very similar to representative foreign groups, with a new genotype in each group resulting in their genetic diversity.