• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.272-278
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• 2001

To investigate of C and N metabolisms in response to phosphorus-deficient stress during regrowth of Italian ryegrass (Lolium multiflorum L.), C and N metabolites were analyzed at 0, 6, 12 and 24 days after defoliation. P-sufficient (control, +P) and P-absent (-P) nutrient solutions were applied from 7 days before defoliation, and continued for one cycle of 24 day-regrowth period. During 24 days of regrowth, dry matter of regrowing shoots and remaining tissues were not significantly different between +P and -P treatment. In remaining stubble, 70% to 91 % decline of the initial level (at day 0) in all C compounds occurred during the first 6 days of regrowth. Initial amounts of nitrate and amino acids in roots were significantly higher in the +P medium. Nitrate contents in stubble in the +P medium significantly decreased for the first 12 days and then rapidly recovered, while that of the -P medium continuously decreased until day 24. Amino acids in stubble in the P medium were continuously increased during the whole regrowth period. Soluble proteins in stubble in the +P medium also largely fell down (46.0% of the initial) for only the first 6 days, however the decline in the -P medium continued until day 12. In regrowing shoots, the accumulation of C compounds was significantly higher, while that of N compounds except amino acids was largely lower in the -P medium. These results showed a stimulation of carbohydrate synthesis and a compensatory utilization of organic reserves occurred to support regrowth under P-deficient condition.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.667-673
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• 2010

Organic agriculture of especially medicinal crops has been interested and focused in taking the qualitative and safety agricultural products in order to maintain and improve the health and happiness of people. With respect to the organic agriculture relating to cropping system, objectives of this study were to examine the seedling establishment after seed germination and emergence and to investigate the early seedling growths of Astragalus membranaceus Bunge with treating two green manure crops, hairy vetch of legume and rye of gramineae, two different conditions of green manures, fresh and dry, and different seeding times. When the seeds were planted at once after treating the green manures with the fresh condition into the soil, the ratios of seedling establishment were very poor, less than 10% in hairy vetch and 20% in rye, respectively. They were increased gradually with delaying the seeding times after the treatments. With treating the green manures of dry conditions, the ratios of seedling establishment were up more than 50% in both hairy vetch and rye crops, showing that the damages of seedling establishment were more in hairy vetch than those in rye. The early seedling growths were slower in treating the green manures than those in the control, showing slow growth with fresh green manures compared to the dry. It would be very important and considered more to evaluate and utilize well the seed germination and the seedling establishment in cultivation of the organic agriculture using the green manure crops relating to the cropping system.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.526-537
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• 1993

The development of composting techniques is essential to the low input sustainable agriculture. This paper resents an evaluation of composting system, compost materials, aeration & temperature effects, compost maturity , and operational concerns for compost utilization. The composting of organic waste is markedly affected by the nature of the feedstock and the operational temperature employed for the process. These two major parameters are critically examined in this paper, with references to the decomposition of the organic waste. Future research should concentrate on the indications of stability and environmental problems.

• Korean Journal of Organic Agriculture
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• v.11 no.2
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• pp.61-78
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• 2003

This study compared the levels of North Dakota and South Korean conventional and sustainable farmers' participation in community organizations. The North Dakota data were collected in 1990 from a sample of 568 farm and ranch operators. and the South Korean data were collected in late 1999 and early 2000 from a sample of 147 farmers through interviews and surveys. The data were analyzed using the SPSS ANOV A computer program. The sustainable farmers in both countries were more likely to participate in community organizations than the conventional farmers. Nevertheless, through this comparative study it was found that some differences between two countries exist due to their different cultural backgrounds. Whereas Americans were oriented more to morality and ethics influenced by church, farmers in Korean were more influenced by civil movements. Whereas the reduced tillage farmers in Americans were more likely to be sustainable farmers, the mixed farmers in Korea were more likely to belong to conventional farmers. While individuals in community organizations focused on the economics of agriculture, sustainable farming and farmers' social participation were social matters, which were used to develop sustainable community.

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.313-333
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• 2022

In Muju County, one of Korea's major apple producers, the regional agricultural cooperatives united together and invested to establish a cooperative joint business corporation in charge of the sales business. The corporation carried out the sales business transferred from the participating regional agricultural cooperatives. While the two participating cooperatives showed a marked difference in the degree of participation at the beginning of the business, the introduction of the agricultural product processing centers (APCs) and the participation of co-selection and shipment organizations and general farms helped settle this gap. In addition, commercialization through the APCs enhanced the market competitiveness of apples, which led to the stable securing of sales outlets. The corporation integrated the sales business in the county and this resulted in increased sales volume and sales revenue. Playing a leading role in introducing and cultivating new crops on a trial basis, the corporation demonstrated its potential as the main body of the joint sales business.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.690-697
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• 2012

Approximately 67% of the total land area of the Korea is covered by forest. Eutrophication, defined as the enrichment of waters beyond natural levels, principally by the nutrient phosphorus (P), is a serious cause of concern at the present time. The contribution of forestry to P loading in catchment waters has not been intensively studied in Korea, but is potentially important because forests are often located in near-pristine environments. Phosphorus is retained by most mineral soils and, as a consequence, losses are usually negligible. However, it is much more mobile in organic soils where it can be relatively easily leached or lost through surface runoff, as these soils have a low capacity to retain free phosphate. This report has been prepared to study the influence of arable land used for paddy, upland, and forestry on water quality in the basin of Daechung reservoir.

• YAKHAK HOEJI
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• v.41 no.2
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• pp.153-160
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• 1997

One hundred and seventy crude drugs were screened for prolyl endopeptidase (PEP) inhibitors. Among them, 80% methanolic extract of 18 medicinal plants such as Polygonum cuspi data, Sanguisorba officinalis, Eugenia caryophyllata, Rubus coreanus, Cinnamomum cassia (Cassiae Cortex and Cinammomi Ramulus), Rheum palmatum, Ulmus pumila, Sorbus commixta, Areca catechu, Uncaria sinensis, Terminalia chebula, Caesalpinia sappan, Nelumbo nucifera, Machilus thunbergii, Paeonia moutan, Elscholtzia patrini and Cynomorium coccineum inhibited more than 70% of PEP activity at a concentration of 40 ppm. The active principles of P. moutan, M. thunbergii, T chebula, A. catechu, S. commixta, R. palmatum, R. coreanus, E. caryophyllata and P. cuspidata were transferred into organic solvents, which showed more than 75% inhibition at 5 ppm.

• Korean Journal of Environmental Agriculture
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• v.38 no.2
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• pp.96-103
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• 2019

BACKGROUND: This study was conducted to develop selenium (Se)- and germanium (Ge)-enriched rice by foliar spray application of organic or inorganic Se and Ge. METHODS AND RESULTS: The time and frequency of organic or inorganic Se and Ge treatment were performed at the five main growth stages as followings: effective tillering stage (E), maximum tillering stage (M), booting stage (B), heading stage (H), grain filling stage (G). The main treatment plots were consisted of (1) 'once' treatment (at each E, M, B, H, G stage, Se/Ge single apply), (2) 'twice I' (at H + G stages, organic or inorganic Se/Ge apply), (3) 'twice II' (at H + G stages, mixture apply of Se + Ge + pesticide). The organic or inorganic Se treatment concentration was 20 and 40 ppm, and the Ge was 50 and 100 ppm. The Se and Ge contents in rice grain (brown rice and polished rice) were analyzed by inductively coupled plasma (ICP). The highest Se content was noted in brown rice 'twice I' with Se 40 ppm (1394.06) at H + G stages, but the lowest was in 'once' with Se 40 ppm ($367.79{\mu}g{\cdot}kg^{-1}$) at B stage. The highest of Se content in polished rice was found in 'twice I' of Se 40 ppm (1090.25) at H + G stages, but the lowest was in 'once' with Se 40 ppm ($403.53{\mu}g{\cdot}kg^{-1}$) at E stage. On the other hand, The highest of Ge content in brown rice was found in 'twice I' with Ge 100 ppm (398.66) at H + G stages, but the lowest was in 'once' with Ge 100 ppm ($139.64{\mu}g{\cdot}kg^{-1}$) at B stage. The highest of Ge content in polished rice was found in 'twice I' of Ge 100 ppm (300.29) at H + G stages, but the lowest was in 'once' with Ge 100 ppm ($142.24{\mu}g{\cdot}kg^{-1}$) at B stage. CONCLUSION: Se and Ge contents both in brown rice and polished rice treated with organic Se and Ge forms were higher than those of inorganic Se and Ge. Overall results concluded that the supplementation of organic Se and Ge contents in brown and polished rice contents were comparatively higher than the inorganic Se and Ge. This is results also proved that the foliar spray application of organic Se and Ge has positive nutritive effect on the rice for regular consumption.

• Journal of Life Science
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• v.22 no.10
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• pp.1324-1329
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• 2012

The objective of this study was to evaluate the in vitro effects of organic acids on methane emission and ruminal fermentation characteristics. We expected our methodology to result in a decrease of methanogens attached to the surface of rumen ciliate protozoa by addition of organic acids and in particular a decrease in methane emission. A fistulated Holstein cow of 650 kg body weight was used as a donor of rumen fluid. Organic acids (aspartic acid, fumaric acid, lactic acid, malic acid, and succinic acid) known to be propionate enhancers were added to an in vitro fermentation system and incubated with rumen fluid. The microbial population, including bacteria, protozoa, and fungi, were enumerated, and gas production, including methane and fermentation characteristics, were observed in vitro. Organic acids appeared to affect the rumen protozoan community. The rumen protozoal popuation decreased with the addition of aspartic acid, fumaric acid, lactic acid, and malic acid. In particular, the methane emission was reduced by addition of lactic acid. The concentration of propionate with all organic acids that were added appeared to be higher than that of the control at 12 h incubation. Addition of organic acids significantly affected rumen bacteria and microbial growth. The bacteria in added fumaric acid and malic acid was significantly higher (p<0.05) and protozoa was significantly lower (p<0.05) than that of the control. Microbial growth with the addition of organic acids was greater than the control after 48 h incubation.

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.219-228
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• 2014

Even though consumers' concern about food-safety certified or environment-friendly chicken meat becomes one of the main issues of food consumption in Korea, university students' interest about food-safety certified or environment-friendly chicken meat was not often discussed. We realized that the cafeteria of university is one of the largest consumption points for the chicken meat of university students, and tried to analyze university students' consumption of food-safety certified or environment-friendly chicken meat at the cafeterias of university. The object of this paper is to conduct survey analysis about the students' behavior for consumption of food-safety certified or environment-friendly chicken meat at the cafeterias of university and to measure WTP(Willingness-to-pay) for the food cooked with food-safety certified or environment-friendly chicken meat. The results present that most of students show higher preference of environment-friendly chicken meat than food-safety certified chicken meat, and that they can pay 1,329.9 Korean won for food cooked with environment-friendly chicken meat.