• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.245-256
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• 2008

The current legislation in South Korea clearly states that the tolerance threshold on the adventitious presence of GMO in environment-friendly agricultural products is 3.0% and no GM seed should be detected in their planting seed batches. To date, in Korea, there is no approved GM crop for commercial cultivation in field. However, several GM crops including rice, Chinese cabbage, potato and wild turf grass are currently under risk assessment for their environmental release. Also Korean government (Rural Development Administration, RDA) announced that 11 institutes including universities have been currently certified to carry out a risk assessment of GM crops. Meanwhile, the cultivated area and certified quantities of environment-friendly crops (organic, pesticide-free and low-pesticide) are sharply increasing every year according to the report of National Agricultural Products Quality Management Service (NAQS). In detail, in 2007, the certified quantities of environment-friendly agricultural products were elevated up to 100-fold for organic, 171-fold for pesticide-free and 2,324-fold for low-pesticide crops when compared with those in 1999. The total certified quantity of environment-friendly cereal crops in 2007 was equivalent to 6.4% of total production of cereal crops. Moreover, 24% of total production of root and tuber crops such as potato and sweet potato were certified for environment-friendly agricultural products. In these circumstances, I strongly suggest that current legislations on GM crop's safety management should be revised to include strategies for the coexistence of GM with non-GM crops, especially environment-friendly crops before GM crop is approved to be cultivated for commercialization. Since all types of crops are grown in an open environment, the adventitious presence of GM crops among non-GM crops is inevitable if appropriate measures for coexistence are not established for species by species such as isolation distance, workable management measures to minimize admixture.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.71-76
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• 2015

Developed countries have set seed industry as a new growth engine, which demands strong support from the government. Multinational seed companies such as Monsanto and DuPont have made huge financial investment to secure their major roles in the global market. To spur domestic seed industry performance, Korean government laid out the foundation for developing seed industry through policy promotion in the late 2000s. In this paper, I look at the current state of the domestic and international seed market to provide information for improving the efficiency of the propulsion of the Golden Seed Project (GSP) along with its vision. The increasing size of global giant companies has been regarded to monopolize the world seed industry wherein ten renowned companies occupy 73% of the overall global market. In effect, this causes a price hike due to limited seed choices. Domestic seed market has been stuck in a range due to a sustained low agricultural production resulting in decreased seed demand and market size. Though breeding technologies for rice and vegetables are world-class, the technologies for top global crops such as cabbage, paprika, and forage are insufficient therefore professionals in this field are not easily employed. Moreover, there is a lack in appropriate infrastructure set up in the universities which adds to ineffective training of professionals. Being a key-supporting industry for agriculture, seed industry should be granted with strong and sustainable investment support from the government. In view thereof, GSP, which started in 2012, ambitions to spur researches outlined by excellent professionals in universities and seed companies aimed to drive seed export volume and quality and attain domestic seed self-sufficiency through adoption of export- and import-substitution seed types (10 varieties each) development strategies. To develop Korea's seed industry excellent achievement of GSP's goals should be drawn successfully and to do this beside development of high quality seeds, support programs for promotion of seed exports are also needed.

• Korean Journal of Weed Science
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• v.3 no.1
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• pp.69-74
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• 1983

The behaviour of mixtures of herbicides was determined to obtain the basic informations about effective herbicide use, enhancing herbicidal efficacy and reducing the chemical cost. Fourteen herbicides with 91 mixed combinations were evaluated by Limpel et al method at the Echinochloa crus galli Beauv-Monochuria vaginalis Presl.-Scirpus hotarui Ohwi (importance values of these weeds were 63%, 16% and 10%, respectively) community type. Thirty eight mixed combinations showed the antagonistic response. Among these 14 mixed combinations including chlormethoxynil + naproanilide mixture were greater than 11% in antagonistic effect. On the other hand, 40 mixed combinations including chlormethoxynil + SW751 mixture showed additive response (${\pm}2%$). For synergistic response, 13 mixed combinations were belonged to this group. Particularly, 3 mixed combinations, chlormethoxynil + butachlor, chlormethoxynil + bifenox and nitrofen + ACN/MCPB/nitrofen mixtures were greater than 11% in synergistic effects. The mixture of thiobencarb + oxyfluorfen was analyzed by isobole technique. This mixture showed the synergistic response and the interaction index was approximately 2. The most optimum mixtur for inducing 90%n weed suppression was 0.012 kg ai/ha for oxyfluorfen and 0.45 kg ai/ha for thiobencarb.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.24-30
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• 2011

BACKGROUND: High input to the arable land is contributed to increasing productivity with causing the global environmental problems at the same time. Rapeseed cultivation has been forced to reassess its positive point for utilization of winter fallow field. The Objective of this study was performed to assess the environmental impact of rapeseed cultivation with double-cropping system in paddy rice on Yeonggwang district using life cycle assessment technique. METHODS AND RESULTS: For assessing each stage of rapeseed cultivation, it was collected raw data for input materials as fertilizer and pesticide and energy consumption rate by analyzing the type of agricultural machinery and working hours by 1 ton rapeseed as functional unit. Environmental impacts were evaluated by using Eco-indicator 95 method for 8 impact categories. It was estimated that 216 kg $CO_2$-eq. for greenhouse gas, 3.98E-05 kg CFC-11-eq. for ozone lazer depletion, 1.78 kg SO2-eq. for acidification, 0.28 kg $PO_4$-eq. for eutrophication, 5.23E-03 kg Pb-eq. for heavy metals, 2.51E-05 kg B(a)p-eq. for carcinogens, 1.24 kg SPM-eq. for smog and 6,460 MJ LHV for energy resource are potentially emitted to produce 1 ton rapeseed during its whole cultivation period, respectively. It was considered that 90% of these potential came from chemical fertilizer. For the sensitivity analysis, by increasing the productivity of rapeseed by 1 ton per ha, potential environmental loading was reduced at 22%. CONCLUSION(s): Fertilization affected most dominantly to the environmental burden, originated from the preuse stage, i.e. fertilizer manufacturing and transporting. It should be included and assessed an indirect emission, which is not directly emitted from agricultural activities. Recycling resource in agriculture with reducing chemical fertilizer and breeding the high productive variety might be contribute to reduce the environmental loading for the rapeseed cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.4
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• pp.215-220
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• 1974

The relation between yield or total dry matter yield and nitrogen, phosphorus, potassium or silica uptake was investigated according to simple or multiple correlation coefficients, and multiple regression equations. 1. Simple correlation coefficient was always higher with total dry matter yield than with grain yield and highest with N in no nitrogen (0-6-8) or no fertilizer (0-0-0) plot, with P in no phosphorus plot (10-0-8) but lowest with K in no potassium plot (10-6-0). 2. Multiple correlation coefficient was always higher than simple correlation and the same is true with including Si as one more variation. There was clear trend that multiple correlation coefficient was highest in no fertilizer plot and lowest in no potassium plot. 3. Simple correlation coefficient with P was higher in the warm year in which P uptake and fertilizer-P use efficiency were higher while it with K was higher in the cool year in which K uptake and fertilizer-K use efficiency were higher. Nitrogen and silicate followed potassiuum. But partial regression coefficients of N. P. K and Si with yield were mostly significant only in the warm year. 4. Partial regression coefficient of K was negative in many cases with yield but significant positive value with total dry matter yield. 5. Partial regression coefficients of N. P and K were decreased when Si was included and the decrease was great in P. 6. With the increase of nitrogen fertilizer level partial regression coefficient was increased in N but decreased in P, and no consistency in K or Si. 7. According to single or multiple correlation coefficients and partial regression coefficients the contribution of nutrient to grain yield appears to be in the order of N > Si > P > K and to total dry matter yield in the order of N > K > Si > P, indicating that N is the main factor and others are closely related to each other throughout to N. The superiority of N was also proved by frequency pattern of relative yield.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.3
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• pp.153-170
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• 1977

Considering the ways for the possible improvement of soil test for upland crops, various methods for the evaluation of K supplying power and testing of available soil K were reviewed in terms of theoretical principles and practical usefulness of the each method. The review was also made on the characteristics of upland crops in K requirement and on the chemical properties of major korean upland and lowland rice soils in terms of K availability. Following is the few remarks drawn from the review. 1. Quite large number of methods have been known for the evaluation of K supplying power and testing for available soil K. In nature, they can be divided into two categories; capacity-based methods and intensity-based methcds. The capacity-based methods usually measure the exchangeable and some portion of nonexchangeable K, while the intensity-based methods suggest to consider the ractivity ratios of major cations in soil solution and the energy requirement for the replacement of exchangeable soil K into soil solution. 2. As methodology for extraction of interested part of soil K, chemical extraction, electrodialysis and ion exchange methods have been known. Among these, chemical extract ion is favorable because of its simplicity. However, recently suggested Electro-Ultra-Filtration method seems to merit further study for wider use for not only K but also other nutrient availability of soils. 3. The intensity-based methods, although they are more theoretical, because of their complexity, in methods may not be adapted for practical soil tests. 4. The exchangeable K which is rather simple to measure and which well reflects the status of K reserve as nonexchangeable and is immediate pool of water soluble K may be good, if not best, criterion of soil K availability to plant in common soil testing. 5. Because there are evidences that the abundance of available K alone may not be good inclication for availability of K to plant, it is recommendable to interprete the exchangeable K data as percent saturation of exchangeable K to total C. E. C. of soil for the recommend ation of K fertilizer based on soil tests. 6. Some pot and field trial results showed the trends that percent potassium saturation to total C. E. C. better serve as the parameter for K fertilizer recommendation.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.140-146
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• 2010

Monitoring of the dynamic changes at paddy rice agriculture is very important for agricultural sustainability. Field monitoring was performed to evaluate the soil chemical properties of 260 paddy soil samples every four years from 1999 to 2007 in Gyeongnam Province. Soil chemical properties such as pH, organic matter, available phosphate, silicate, exchangeable potassium, calcium, and magnesium contents were analyzed. The contents of exchangeable cations, and available silicate were significantly increased in 2007 compared to 1999. The chemical contents of organic matter, exchangeable potassium, and magnesium were significantly increased in acid sulfate soil, and silty clay loam compared to those of other soil types, and textures. Especially, content of organic matter was significantly increased in hill area compared to other soil topographies, while exchangeable potassium was significantly decreased. Principle component analysis (PCA) of chemical properties in paddy soils was obtained with eigenvalues > 1 summing 39.1%of variance for PC1, 20.4%of variance for PC2, and 59.5%of the total variance in the all of soil chemical properties. Therefore, principal component analysis is more effective for monitoring from chemical properties of paddy soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.385-393
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• 2011

Soybean is the most promising crop for substituting rice on the paddy field. Excessive water stress is a common limiting factor in soybean yield under paddy soil condition. This study was carried out to identify changes in leaf total nitrogen and petiole ureide content under excess water conditions for establishing a screening system related to waterlogging tolerance. Waterlogging treatment was conducted by maintaining the water level on the soil surface for 10 days at the early vegetative growth stage ($V_5$) and the flowering stage ($R_2$). Leaf total nitrogen content, SPAD value and ureide content in petiole decreased in all soybean varieties in response to waterlogging, but the degree of decrease was much lesser in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong, at 21 days after waterlogging treatment. This result means that root and nodule recovery rates were much higher in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong after waterlogging treatment. The ureide and leaf nitrogen content showed high positive correlation with SPAD value, regardless of waterlogged stages. In conclusion, leaf nitrogen content, ureide content in petiole and leaf greenness were identified as promising indicator for screening soybeans which are tolerant of excess water.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.117-122
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• 2005

To find out reducing way of methane emission from a paddy field monitoring on the greenhouse gases emissions were carried out in the paddy soil with livestock compost and soil conditioner. The seasonal variations of methane emission were high at 36 days and 86 days after rice transplanting, on the other hand those of nitrous oxide emission were high at 64 days after that day. Methane emission by cow compost application, pig compost application and chicken compost application were 331, 282 and 294 kg $ha^{-1}$, respectively. Otherwise, nitrous oxide emissions by cow compost application, pig compost application and chicken compost application were 1.60, 1.78 and 1.78 kg $ha^{-1}$ respectively. The total emission rate of greenhouse gases equivalent to $CO_2$ emission rate (GWP) was 7,447 kg $ha^{-1}$ in cow compost application, 6,474 kg $ha^{-1}$ in pig compost application and 6,726 kg $ha^{-1}$ in chicken compost application. Methane emission by Ca, $SiO_2$ and artificial zeolite application were 373, 264, 239 kg $ha^{-1}$, respectively. The total emission rate of greenhouse gases equivalent to $CO_2$ emission rate (GWP) was 8,295 kg $ha^{-1}$ in Ca application 5,978 kg $ha^{-1}$ in $SiO_2$ application and 5,447 kg $ha^{-1}$ in artificial zeolite application.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.114-120
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• 1985

This study was conducted to investigate the important weeds occurring in onion and garlic planted in paddy field as the succeeding crop of rice and to evaluate the effect of competition between these crops and weeds on the yield of onion and garlic. In terms of quantity occurred, Persicaria hydropiper, Chenopodium ficifolium, Alopecurus aequalis, Poligonum aviculare, Echinochloa crus-galli, and Bothrisospermum tenellum appeared to be the major weeds in onion and garlic fields. Annual broadleaves were composed of 90.0 and 94.3% of total weed dry weight in onion and in garlic fields, respectively. Among these weeds, P. hydropiper was the most dominant species in onion and C. ficifolium in garlic fields. The higher Simpson's index such as 0.67 in garlic as compared to 0.40 in onion can be attributed to the presence of a C. ficifolium, which is existed in a single dominant species. The full season competition between the crops and these weeds resulted in yield reduction of onion by 23.9% and garlic by 31.9%, showing weed dry weight, 448.18 and 418.40 g/$m^2$ in onion and garlic fields, respectively. The maintenance of weed free condition for about 4 weeks after weed emergence could be the prerequisite to obtain the maximum yield of these two crops.