• Korean Journal of Organic Agriculture
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• v.19 no.4
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• pp.513-528
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• 2011

This study was conducted to evaluate the nutritional value of locally produced organic agricultural by-products to substitute imported organic feeds for organic ruminant farming. Imported organic feeds (corn grain, soybean meal, soybean seed, oat grain, barley grain, wheat grain, buckwheat, sunflower seed meal) and byproducts (rice bran, grape seed meal, rice straw, soybean hull, soybean curd, rice hull, green kernel rice, and crushed rice grain) were analyzed for chemical composition and NDF, ADF, mineral, and amino acid contents and anti-nutritional factors. Dry matter, NDF and ADF contents in organic feeds were higher than those in conventional feeds. Especially, the 9.65% fat content of organic soybean meal was 6 times higher than the 1.95% fat content of conventional soybean meal. Fat contents of rice bran, grape seed meal, green kernel rice, and crushed rice grain were 25.66, 6.09, 3.57 and 1.59%, respectively. Protein contents of soybean hull and soybean curd were 14.68 and 19.87%, respectively, which are highest among organic by-products. Levels of aflatoxin in all feeds were below the safety level. Therefore, organic rice bran, green kernel rice and crushed rice as energy source, and soybean hull and soybean curd as protein source could partial replace imported feeds for organic ruminant farming.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.257-269
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• 2010

To investigate the possibility of discrimination between organic and non-organic rice using stable isotope nitrogen of natural abundance, organic rice of 17 samples and non-organic rice of 13 samples grown at adjoining organic rice field were collected in 2008. Rice was grinded into brown rice, milled rice and hull, and samples were analysed for nitrogen and $\delta^{15}N$ at NICEM. Authors also made inquiries about N source for both farmers who conduct organic- and non-organic rice cultivation. In order to know whether the $\delta^{15}N$ can be used in discrimination between organic and non-organic rice, discriminant analysis were made with SPSS and logistic method. 1. Organic farmers used manure, rice bran, used mushroom culture, fermented fertilizer (company products), and oil cake, but non-organic farmers applied compound fertilizer. Rice straws were remained in organic rice field while moved out in non-organic field. 2. There were difference in $\delta^{15}N$ among organic rice and its byproduct(7.760????% in hull, 6.720????% in rice), but significant difference was not found between them. And the trend was same between province. Non-organic rice showed similar results. 3. Significant difference of $\delta^{15}N$ were found between organic rice and non-organic rice (p<0.01) and between hull of organic rice and that of non-organic rice hull (p<0.05). $\delta^{15}N$ seemed to be useful criteria for discrimination of organic and non-organic rice. 4. When applied discrimination analysis of SPSS and logistic, there were significant difference between organic rice, non-organic rice and its byproducts except brown rice and hull in SPSS method. Hull can be used as the most useful component for unknown sample prediction with 83.3% probability.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.74-77
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• 2011

The production practices, productivity and economic performance of organic and non-chemical rice farming were compared in Jeonnam Province, Korea. Korean organic rice farming showed a lack of use of resistant varieties and rotational cropping systems as well as less use of farm wastes and a high dependency upon external inputs. When compared with no-chemical rice production practices very little differences were found. However, organic rice farming showed 15% to 18% higher profits than no-chemical farming even though the productivity was arguably similar between the two farming types. This may encourage more farmers to convert to organic production rather than non-chemical farming as the farming practices are very similar, thereby resulting in increased supply of organic products and decreased prices for organic rice near future. There is a need to more greatly differentiate organic farming practices and products from those of no-chemical farming.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.135-138
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• 2011

In traditional organic rice culture practices, control of weeds is a big problem. This study was conducted to increase the rice production. Results showed that Plant height, SPAD, root length and weight were higher in pot raised seedling than broadcasting method except number of panicles. High plant density caused reduction in plant height, number of culm and chlorophyll content of the rice. No lodging was observed in both methods. Thickness of third internode and culm length was more in pot raised seedlings at both sites. When organic material was used rice yield increased by 3.81%. Higher rice production (10%) was recorded in the fields planted with pot raised seedlings. From the above study it could be conclude that the pot raised seedlings perform better than the seedlings raised by broadcasting methods.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.355-361
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• 2015

The rice protein profiles of Oryza sativa L (Koshihikari) grown under organic and conventional cultivation regimes were compared on 2-D gels to develop diagnostic marker proteins for organic rice. The selected proteins, differentially expressed between organic and conventional rice, were compared with the differentially expressed proteins of another organic and conventional rice pairing, produced at a different location. In the first comparison among conventional, no-chemical, and organic rice grown in the same region, Korea, 13 proteins exhibiting differential expression in organic and conventionally grown plants were selected. Eight of the 13 proteins were down-regulated, and the 5 remaining proteins were up-regulated from conventional to organic rice. The second comparison pairing from Kyungju, revealed 12 differentially expressed proteins, with 8 down-regulated and 4 up-regulated proteins. Ten of the differentially expressed proteins that overlapped between the two comparison sets could not be clustered into any functional group using a functional annotation clustering tool. Further comparisons using another set of conventional and organic rice, belonging to a different variety of Oryza sativa L and produced in Sanchung, revealed 8 differentially expressed proteins, 5 of which were down-regulated and 3 of which were upregulated in the organic rice. Overall, 3 differentially expressed proteins were commonly found in all three organic rice crops. These 3 proteins, along with other overlapping differentially expressed proteins, can provide a good starting point for the development of signature proteins that can be used for the authentication of organic rice with a follow-up studies with more comparison sets.

• Korean Journal of Organic Agriculture
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• v.18 no.1
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• pp.1-19
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• 2010

This paper evaluates potential environmental impacts and external costs on rice production of Korea. The investigation is based on LCA in agricultural area which estimates inputs and outputs of rice production system in quantitative way. The results show that environmental impacts on organic rice(4.49E-08 DALY/kg) is level on 4.5% out of conventional rice(9.97E-07 DALY/kg). The external costs of organic and conventional rice are 4.04won/kg and 89.52won/kg respectively. The balance of both organic and conventional rice which is 85.48won/kg represents monetary value on improvement of environmental effects as producing organic rice.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.3
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• pp.175-194
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• 1979

The soil organic matter contents in arable land are generally low in Korea. Thus it is generally agreed that the application of organic materials to soils would be much beneficial. Present paper is a review on the effectiveness of organic mat ter application in uplands and lowlands. 1. The effect of organic matter application in uplands are of more clear and simple to explain as compared to that in lowlands. In uplands, appropriate application of organic matters such as compost and various crops residues improves the physical properties of soils leasing to increased water holding capacity, better aeration, and decrease in soil erosion. 2. In lowland, rice soils under water logged conditions the effect of organic matter application on rice yield is not straight borward and demands more refined knowledges for the interpretation of it. 3. It is found that the application of compost in rice soils is more effective when nitrogen fertilizer application is limited it dicating that nitrogen contained in the organic maerials can become available to rice plant and plays an important role for increased yield of rice under the condition where nitrogen fertilizer supply is limited. 4. Application of organic matter does not always bring about the desirable effects. Very often the organic matter application results in more intensive soil reduction leading to the accumulation of harmful substances which would can cancel out the positive effects of organic matter. This is partiunlarly true in poorly drained soils. 5. Rice straw or compost, when applied rice soils, supply sizeable amounts of available silicate to rice plant resulting in yield increase. 6. Although the effectiveness of organic matter application on rice yield in short term experiments is not consistent due to many reasons, the long term effect of organic matter is significant. 7. The term of the $O.M/SiO_2$ ratio in rice soils can serve as a criterion for the judgement of whether organic matter or silicate fertilizer is needed to be applied in a certain soil.

• 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.

• Korean Journal of Organic Agriculture
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• v.1
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• pp.19-28
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• 1992

The definitions of organic farming method has rather philosophical meaning than application of agricultural practices. The meaning of organic farming method has certainly basic differences in comparison with the conventional farming methods. The main definitions of organec farming method have certainly to reduce or not to apply any kinds of farm inputs materials by increasing quality of agricultural prod-ucts. However, the quality of produced food by organic farming method should be improved in compari-son with cinvethional farming method. By applying organic method, the qualith of food, envir-onment as well as spiritual attitude of human being should be improved in future. Actually, there are very wide fields of research on organic farming methods such as production tech-niques, soil and water conservation, plant and animal production, marketing and consumers behavior on organic products. In this article the present situation of organic farming methods in the United States of Americal is investigated in cimparison with conventional rice production. The production cost of rice per acre in the United States of America mde 58, 788 Won in 1986, while it was 121, 699 Won in Korea having about 107 percent higher in Korea than tham the U.S.A There is a larger rice farm cost analysis between conventional and organic rice farm in California. The cash cost pre 1 lbs of conventional rice made 4.86 $, while the organic rice was 6.96$ showing about 43.2%higher level of cost in organic products(1 lbs=0.45359kg) At present, there is less econmic advantage of organic rice production in California because of lower yields as well as price levels, Therefore, the total net return over cash cost peracer/yeat was a little lower in organic rice production than conventional rice prouction.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.119-122
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• 2011

Among the developed bio-degradable polymer films as compared with transparent film(White), black polymer film was significantly more effective for controlling weeds in red pepper. Also, we found that white and black polymer mulching had 81.8% and 97.9% of managing weed controlling effects in rice, respectively. Compared to non-mulched rice paddy with water supply, the non-mulched rice paddy without any water supply has stopped its growth at 41 days after transplanting, while polymer-mulched rice paddy without water supply had about 60% of normally growing rice plants. This shows the polymer treatment has a remarkable effect on water and power saving, solution of herbicidal resistance, avoidance of herbicidal influence to eco-system etc. When the naturally decomposing polymer was used, a temperature was elevated as high as $4.7^{\circ}C$ on maximum and $2.6^{\circ}C$ on average. Also the naturally decomposing polymer accelerated rooting by 7 days and lowered a stress level from transplanting. The weed control effect mulched by polymer was remarkable as 98.7%. The polymer now, after 294 days treated on the rice paddy, has been completely decomposed.