• Polymer Science and Technology
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• v.18 no.4
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• pp.319-325
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• 2007

• Korean Journal of Organic Agriculture
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• v.8 no.2
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• pp.97-110
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• 2000

An organic agriculture should be managed by mixed farming in farm unit as a closed recycling system. Due to restricted purchased of fertilizers from outside, organic farmer has to deal with limited amount of nutrient source in farm unit. Especially the supply of the essential nutrient, nitrogen, mostly depends on legumes fixing nitrogen optimizing the site-adapted crop rotation. Dynamics of humus and metabolic plant carbon and active soil carbon compartment in active and passive humuspool by rotation system was explained, and dynamics of potentially mineralizable nitrogen in organic nitrogen and biomass was discussed. It was also discussed comparison of ammonia emission, potential greenhouse effect, primary energy input, acidification potential, CO2 emission between organic and conventional farming, the nitrate-nitrogen dynamic in the soil profile by organic, integrated and conventional farming system. In conclusion, it was suggested for Korean Organic Agriculture that the importance of legumes and green manures in rotation system for increase/maintenance of soil ferfility, and was pointed out the need of investment for environment impact of Korean organic farming implement.

• Asian Journal of Turfgrass Science
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• v.4 no.1
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• pp.24-30
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• 1990

This study was carried out to search for growth and quality -of turfgrass by Nitrogen source (Urea Ammonium sulphate) and organic matter, and to obtain methods of pr6per turfgrass management by the results. This experiment was conducted in turf field from 1988 to 1989. The results of this experiment was summarized as follows; 1.Without application of organic matter, turfgrass growth between urea and ammonium sulphate was not significant, however ammonium sulphate resulted in superior to urea in total dry weight when organic matter was applied. 2.The addition of organic matter showed significant effect on color rating and visible quality, and ammonium sulphate was higher quality than urea. 3.Shoot density increased, particularly in ammonium sulphate treatment, when organic matter was applied. 4.Rhizome and stolon were shown significant effect in urea treatment by the application of organic matter. 5.Surface soil pH was allowed to become slightly acid by the ammonium sulphate treatments, but soil acidity remained mostly unaffected when organic matter was supplied. 6.Total nitrogen of log tissue and organic matter content increased when organic matter w-as applied.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.69-76
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• 2016

To produce the primary data for best management of soil nutrient in organically practiced soils, 75 leading organic farms whose paddy fields were certified as organic were selected. Soil samples were collected from the paddy fields before plowing, and then analyzed for the determination of physico-chemical properties. Soil pH, organic matter and available phosphate were analyzed and averaged 6.2, $25.6mg\;kg^{-1}$ and $88.4mg\;kg^{-1}$, respectively. Contrary to the national-scale-surveyed paddy soils including organic and conventional farming, pH was higher, available phosphate was lower in the organically practiced soils, but organic matter was similar. With the increasing cultivation period in organic, soil pH and porosity were also increased, EC, available phosphate, bulk density and soil hardness were lower than those from the national survey. Organic matter, however, was not significantly changed. The bulk density was negatively correlated with the organic matter content for both surface topsoil ($R^2=-0.5424$) and subsoil ($R^2=-0.6429$) (p<0.05). Soil quality is improved in most of soil chemical and physical composition factors excluding organic matter and available phosphate. However, it is necessary to establish the counter measure plan for organic matter management and to develop phosphate-containing materials which can be used as organic agricultural material in the future.

• Korean Journal of Organic Agriculture
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• v.5 no.1
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• pp.67-77
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• 1996

The Organic agricultural techinques were investigated through the observations made for 3 years of the actual conditions of a farmer who has been practicing organic agriculture over 21 years. The farmer was a member of the Ichijima-cho Organic Agriculture Association. The Farmer had not performed much of the organic agricultural techinques at the beginning of his farming history. However, he has gradually developed techniques upon the experiences with trial and error. The notable characteristic of his basic organic agriculture was the utilization of a suitable organic fertilizer to make the soil fertile. Crop damages by diseases and insect pests were prevented through a fertile soil, raising of good seedlings, adoption of tolerant varieties and planting at a wide spacing and consequently considering not to use chemical pesticides. Introduction of power weeder for weed control and paddy-upland crop rotation reduced the cost of production for farming. The crop pattern and method of land us such as mix cropping, crop rotation and conversion of paddy field-upland fieldd were appeared to be very important in organic agriculture. The organic agricultural techniques get systematized upon the adaptation the regional ecology and the development of skills of the farmer. The most important point to achieve the success in organic agriculture system is not only by the development of the technical matters but also by the building of healthy relation and understandings between producers and consumers.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.255-260
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• 2010

Insect diversities in non-organic and organic Chinese cabbage and pepper fields were studied in 2009. Sixty-two species in 9 orders and 24 species in 6 orders were collected in organic and non-organic Chinese cabbage fields, respectively. In pepper fields, insect diversity was also higher in organic fields than in non-organic ones. Dominance index, diversity index, richness index, and evenness index in organic fields were higher than those in non-organic fields.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.139-147
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• 2002

In order to the development of a new organic compost to exclusive use in a ginseng, we conducted the study of the preparation of organic fertilizer and the application effect of organic fertilizer in cultivation of ginseng. The new organic compost was composed of dryed broad leaves of acorn 40%, puffed husks of rice 40% and organic material mixture 20%. The chemical properties of the organic compost shown that the values of the total nitrogen, available phosphate, pottasium, calcium, magnesium, organic matter and C/N ratio were $17g\;kg^{-1}$, $8g\;kg^{-1}$, $11g\;kg^{-1}$, $14g\;kg^{-1}$, $4g\;kg^{-1}$, $794g\;kg^{-1}$, and 26.7, respectivly. The application effect of organic compost in the cultivation of ginseng shown that survival ratio of above ground plant of ginseng was shown the high value than control, and the ratio of root rot and red colored root were decreased. The optimal amount of organic fertilizer for ginseng seedling was $24M/T\;ha^{-1}$. The chemical properties of the ferilized soil were analyzed.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.805-819
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• 2017

The study was carried out to develop a mathematical model for evaluating the effect of organic fertilizers in organic rice production systems. A function to simulate the nitrogen mineralization process in the paddy soil has been developed and integrated into ORYZA2000 crop growth model. Inorganic nitrogen in the soil was estimated by single exponential models, given temperature and C:N ratio of organic amendments. Data collected from the two-year field experiment were used to evaluate the performance of the model. The revised version of ORYZA2000 provided reasonable estimates of key variables for nitrogen dynamics and crop growth in the organic rice production systems. Coefficient of determination between the measured value and simulated value were 0.6613, 0.8938, and 0.8092, respectively for soil inorganic nitrogen, total dry matter production, and rice yield. This means that the model could be used to quantify nitrogen supplying capacity of organic fertilizers relative to chemical fertilizer. Nitrogen dynamics and rice growth simulated by the model would be useful information to make decision for organic fertilization in organic rice production systems.

• Journal of Distribution Science
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• v.12 no.3
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• pp.17-24
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• 2014

Purpose - This study investigated the main variables of consumer food choice motive and how they affect attitude and purchase intention toward organic foods. The study involved a multiple regression analysis to verify the influence of food choice motive on attitude toward organic food. Research Design, Data, and Methodology - Data was collected through surveys of 280 students and ordinary citizens in Seoul and the Gyeonggi region, using sampling. A multiple regression analysis was performed to confirm the impact of food choice motive on attitude toward organic food, and a regression analysis was performed to identify the impact of attitude toward organic food on purchase intention. Results - Health and environment, among food choice motives, had significant positive influence on attitude toward organic food, whereas convenience, price, and familiarity had no impact. Attitude toward organic food had significant positive influence on organic food purchase intention. Conclusions - As this study identified the impact of organic food choice motive, it may provide baseline data for marketing strategies, to understand consumer attitude toward organic food and purchase intention, and to satisfy consumer needs.

• Korean Journal of Organic Agriculture
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• v.20 no.2
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• pp.143-159
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• 2012

Agricultural income is calculated with producer price, output and management cost. This study compared organic farming with conventional one for agricultural income, producer price and output by items. And then it proposed the method of item selection and crop system from a diversification point of view. The coefficient of variation to producer prices in organic farming was 4.7%, and conventional one was 30.3% because organic products have been produced in a system of contract farming with consumers' cooperative. This result means the price of organic products is stabler than that of conventional price. And agricultural income of organic farming has been generally known more than that of conventional one. However, agricultural gross income of conventional farming was more than that of organic one by 20.3% in 2010. It was caused by output reduction of a few items(fer example; onion, large green onion, potato and young pumpkin) due to freak weather conditions and constant producer price for several years in organic farming. In order to increase agricultural income, appropriate crop selection and system should be introduced to organic farming. A principal crop is the rice plant and 2 subordinate crops are dry crops at bare field and greenhouse respectively. Thus 5 crop systems that agricultural gross income are relatively increased larger among 15 crop systems estimated are rice+ginger+cucumber, rice+ginger+tomato, rice+large green onion+cucumber, rice+sweet potato+cucumber and rice+onion+ cucumber.