• Korean Journal of Weed Science
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• v.1 no.1
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• pp.5-14
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• 1981

Weed is one of the problems in the crop land as well as in uncultivated land, raising the farm management costs. Therefore, the weed control is essential for effective agricultural management. The cost for weed control in Korea occupies on the average 27.6% of the total labor cost required. Agricultural policies since 1960 were transferring from yield increase due to land productivities to increase of income due to labor productivities. Therefore, the weed control by hand is also changed to weed control by chemicals. The weed control by chemicals has also brought about some side-effects and needs better, improved weed control methods. The present weed control situation and related problems were studied to present new approaches for agricultural development in the future. There were 458 species of weeds in 82 families which were growing in the crop land. The weeds to control, however, are 12 in paddy field and 9 in upland. So far weeds in paddy field are well under control, while weeds in upland are poorly controlled due to change in chemical efficiency and chemical damage in the upland. The administration, research and extension work for the efficient use of agricultural chemicals have been done by various institutions, such as Office of Rural Development, Office of Forestry, and chemical companies. The courses for agricultural chemicals were offered in the agricultural colleges. However, the efficiency of chemicals could not be maximized due to the poor relationships among related institutes. The newly established Agricultural Chemical Research Center at the Office of Rural Development and the Korean Weed Science Association are expected to contribute toward improving weed control in Korea. The Korean agriculture in the future will eventually be mechanized and the varieties resistant to high nitrogen application and to high plant density will be required for high yields. The rice will be transplanted earlier and the whole growing period will be extended. The application of organic matter will be increased for increasing soil fertility, and the use of agricultural chemicals will be continued. Under such a condition, the studies on the weed occurrence and its integrated control measures will be needed. Also weed controls in the newly exclaimed land, crop varieties, horticultural varieties, forage crops, and forests are also needed to study. Basic and practical researches for the weed control to improve the labor productivity will be also needed. In order to meet the all requirements for efficient weed control, weed control systems including all the academics, research and extension workers, administratives, farmers and companies should be established. Also securing researchers and education of personnels are pre-required and research funds for the chemical studies should be provided efficiently and timely.

• Korean Journal of Remote Sensing
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• v.25 no.5
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• pp.411-421
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• 2009

This study refers to develop a semi-automatic extraction of agricultural land use and vegetation information using high resolution satellite images. Data of IKONOS-2 satellite images (May 25 of 2001, December 25 of 2001, and October 23 of 2003), QuickBird-2 satellite images (May 1 of 2006 and November 17 of 2004) and KOMPSAT-2 satellite image (September 17 of 2007) which resemble with the spatial resolution and spectral characteristics of KOMPSAT-3 were used. The precise agricultural land use classification was tried using ISODATA unsupervised classification technique, and the result was compared with on-screen digitizing land use accompanying with field investigation. For the extraction of crop growth information, three crops of paddy, com and red pepper were selected, and the spectral characteristics were collected during each growing period using ground spectroradiometer. The vegetation indices viz. RVI, NDVI, ARVI, and SAVI for the crops were evaluated. The evaluation process was developed using the ERDAS IMAGINE Spatial Modeler Tool.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.2
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• pp.171-175
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• 1990

One thousand and seven hundreds and six soybean land reces and 103 wild soybeans of Korea, and 167 cultivars and 71 wild soybeans of exotic were analyzed using polyacrylamide gel electrophoresis to study the distribution of trypsin inhibitor phenotypes. The four ti/ti lines were observed only in Korean native land races. The Ti$\^$*/a allele of cultivar was found to be the highest in Chinese soybean (0,9888) than in Korean soybean(0.8347) and Japanese soybean (0.5954). The heterozygosity of typsin inhibitor in Korean lines occured in relatively high ratio, The percentages of heterozygosity of the Korean land race and wild soybean are 3.6% (N=61) and 9.7%(N=10), respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.9-16
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• 1979

528 Korean land races of barley were examined for IS agronomic traits to determine if any preferential trait associations with early heading and winter hardiness existed in this collection. Eight traits were non-randomly associated with the 1977～'78 cold damage levels, and seven traits were non-randomly associated with heading date. No early heading, least-cold-damaged land race lines were found. However the least-cold-damaged class preferentially associated with mid-early heading land race lines. Ten traits were preferentially associated with the mid-early heading, least-cold-damaged class. The utilization of these associations should increase the probability that genes for winter hardiness will be preserved in the mid-early heading selections from this collection.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.354-361
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• 2010

Soil physico-chemical properties and microbial densities are affected by organic sources and soil amendment applied to improve soil environments or quality. Generally organic fertilizer effects on forage crops yield and soil properties are partly due to changes of soil composition. We investigated the effects of swine slurry (SS), swine slurry composting-biofilteration(SCB) and chemical fertilizer(F) with gypsum(G) combinations on soil physico-chemical properties and yields of summer forage crop in the Sukmoon reclaimed tidal land in Korea. The forage crops used in this experiment were corn and sorghum$\times$sudangrass hybrid(hereafter sorghum). Our results showed that the soil physico-chemical properties in the combined (F+G, SS+G, SCB+G) treatments increased contents of organic matter and exchangeable $Ca^{2+}$, but exchangeable $Na^+$, $K^+$ and $Mg^{2+}$ reduced to 1-10% for two forage crops, compared to non-combined (F, SS, SCB) treatment. The density of soil microorganism such as bacteria, actinomycetes and fungi, increased significantly by SS+G and SCB+G treatments. This means that treatment of combined organic fertilizer with G lowered salinity levels and improved with microbial growth. The combined treatments also increased the total yields 2.3-6.2% for corn and 2.0-8.7% for sorghum, compared with non-combined treatment. This experiment suggests the combined treatments could increase the total yields of summer forage crops and change of soil physico-chemical properties in the Sukmoon reclaimed tidal land in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.187-192
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• 2013

This study was carried out to investigate the incorporation effect of green manure crops (GMC) such as the hairy vetch on improvement of soil environment in reclaimed land during silage corn cultivation over the past two years. Plots consisted of conventional fertilization (CF) and incorporation of GMC were divided by addition rate of nitrogen fertilizer (100 kg $ha^{-1}$) with 30 - 100% of non nitrogen fertilization (NNF). Soil physico-chemical properties and growth and yield potential of silage corn were examined. The tested soils showed strong alkali and saline properties with low contents of organic matter and available phosphate while contents of exchangeable sodium and magnesium were high. Soil salinity increased during cultivation of summer crop. However, corn was not affected by salt content. The fresh weight of GMC at incorporation time was 18,345 kg $ha^{-1}$. Content of total nitrogen was 3.09% and the C/N ratio was 12.8 at incorporation time. Fresh and dry matter yield of silage corn were higher in the order of N30% reduction, CF, N50% reduction, N70% reduction, N100% reduction and NNF. Fresh and dry matter yield potential of silage corn for N30% reduction were comparable to those of CF. Bulk density of the soil decreased with incorporation of GMC, while porosity was increased. The soil pH decreased while content of exchangeable calcium, available phosphate, and organic matter increased. Also contents of exchangeable sodium and potassium decreased with incorporation of GMC. The data indicate that incorporation of hairy vetch can improve soil physical and chemical properties and reduce nitrogen fertilizer application especially for alkali saline reclaimed soil such as Saemangeum reclaimed land.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.87-91
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• 1976

This study was undertaken to learn the over-all influence of fertilizer on soybean culture and the chemical composition of soybean in the reclaimed land. Treatments included five rates of N.P.K: 4.10.8, compost: 1, 000. N.P.K.: 4.10.8 + compost: 1, 000, N.P.K: 2.5.5 kg/10 are as well as unfertilized plot in the reclaimed land and N.P.K: 4.10.8 kg/10 are as a check plot of the cultivated area. The yield of green plant above-ground, grain yield and protein content were higher in the cultivated plot than in the reclaimed land. Maximum yield of green plant or the greatest grain yield occurred in the plot of N.P.K: 4.10.8+compost: 1, 000 kg application and they diminished as the fertilizer application decreased. Yet there was no statistical significance in the chemical seed composition among treatments.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.122-122
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• 2017

Wheat wild relatives that have never been domesticated contained useful genetic resources such as the resistance to abiotic and biotic stresses. Leymus racemosus is one of the wild species. It can grow in a harsh environment like seaside and distribute by healthy rhizomes. Also, it has a useful genetic resource such as salt tolerance and different diseases resistance. Wheat (Triticum aestivum L. cv. Chinese Spring; CS) was crossed with L. racemosus. Wheat-L. racemosus disomic addition lines were produced. The purpose of this study is to identify protein expression in each disomic addition line compared to CS. We performed two-dimensional electrophoresis. Two-dimensional gels stained with coomassie brilliant blue (CBB), a total of 1566 differentially expressed proteins were identified by Progenesis Same Spots software from the cultivars. However, a total of 90 protein spots were identified to be either present or absent or showing significantly differential expression when the difference threshold was set to more than 1.5 fold. However, out of the 90 differentially protein spots, a total of 74 spots were sorted for mass spectrometry analysis. The identified proteins may provide important clues for better understanding the molecular changes in the chromosomes carrying Leymus racemosus.

• Agribusiness and Information Management
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• v.11 no.1
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• pp.1-9
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• 2019

This research intends to propose the methodology for analyzing the current trends of agriculture, which directly connects to the survival of the nation, and through this methodology, identify the agricultural trend of Korea. Based on the relationship between three types of data - policy reports, academic articles, and news articles - the research deducts the major issues stored by each data through LDA, the representative topic modeling method. By comparing and analyzing the LDA results deducted from each data source, this study intends to identify the implications regarding the current agricultural trends of Korea. This methodology can be utilized in analyzing industrial trends other than agricultural ones. To go on further, it can also be used as a basic resource for contemplation on potential areas in the future through insight on the current situation. database of the profitability of a total of 180 crop types by analyzing Rural Development Administration's survey of agricultural products income of 115 crop types, small land profitability index survey of 53 crop types, and Statistics Korea's survey of production costs of 12 crop types. Furthermore, this research presents the result and developmental process of a web-based crop introduction decision support system that provides overseas cases of new crop introduction support programs, as well as databases of outstanding business success cases of each crop type researched by agricultural institutions.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.265-279
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• 1987

About 140 weed species belonging to 42 families occurring in summer were observed in Ulreung island. The Compositae was the most wildely occurring family covering 27 weed species, followed by 21 species in Graminae, 9 in Polygonaceae, 7 in Leguminosae, and 7 in Labiatae etc. In terms of the lands classified, about 60 species in 26 families were observed in the cultivated and the medical crops grown areas, respectively, and 116 species in 40 families occurred in the non-cultivated land like the vicinity of the cultivated area and 94 species in 34 families in the valley. No. of species and families were much greater in the non-cutivated land than those of the cultivated one. The most dominant weed species in both the cultivated and its vicinity in Ulreung island were Digitaria sanguinalis, followed by Portulaca oleracea, Polygonum hydropiper, Equisetum arvensis, Artemisia princeps, Commetina communis, Setaria viridis in order. Community analysis was done by the method of Toyohara in two cultivated lands such as the general crop land and the medical herb crop grown land, and two non-cultivated areas such as the vicinity of the cultivated land and valley. The cultivated land consisted of the communites of P. hydropiper and Cyperus amuricus, including Bidens tripartita in P. hydropiper community. The medical crop grown land composed of three major communities like P. hydropiper, Amaranthus mangostanus and Sonchus asper in which A. mangostanus and S. media were presented in the ecoton, indicating community being transiting. In the non-cultivated areas like the vicinity of crop land, the communities of Erigeron annuus, P. oleracea, and Oxalis corniculata were dominant, and Dystaenia takeshimana was included in the community of E. annuus and Stellan'a aquatica in P. oleracea community. In the valley, Ranunculus quelpaertensis community was existed in between the communities of Sonchus asper and Plantago asiatica.