• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.268-275
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• 1997

High prices of raw materials used as media for the mushroom cultivation increased the cost of commercial production of oyster mushroom (Pleurotus ostreatus). In this study, garlic peels (Allium sativum f. pekinese) as an agricultural by-product were investigated to replace the saw dust for the bottle cultivation of oyster mushroom. Mycelial growth of oyster mushroom were examined by the extracts made from the sawdust, rice bran and garlic peels. The mycelial growth was very poor in the agar media containing the extracts of sawdust or garlic peels, but was good when those of the rice bran were added. In the polypropylene bottle experiment, the sawdust medium which ammended with minerals vitamin was essential for the production of the mushroom fruitbodies. The rice bran was considered to stimulate the mycelial growth, but not the development of basidiocarps. The garlic peel was not a factor to stimulate the production of mushroom fruitbodies, but a raw material ammended with the rice bran produced much amounts of mushroom. In this work, garlic peels ($10{\sim}70%$ v/v) added to the mixture of sawdust and rice bran (4 : 1, v/v) was considered to help the productions of mushroom fruitbodies. Based on the result, the replacement of expensive saw dust with inexpensive garlic peels was a good example to reduce production cost of the bottle cultivation of mushroom.

• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.33-38
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• 2007

Nitrogen management at the panicle initiation stage(PI) should be fine-tuned for securing a concurrent high yield and high quality rice production. For calibration and testing of the recommendation models of N topdressing rates at PI for target grain yield and protein content of rice, three split-split-plot design experiments including five rice cultivars and various N rates were conducted at the experimental farm of Seoul National University, Korea from 2003 to 2005. Data from the first two years of experiments were used to calibrate models to predict grain yield and milled-rice protein content using shoot fresh weight(FW), chlorophyll meter value(SPAD), and the N topdressing rate(Npi) at PI by stepwise multiple regression. The calibrated models explained 85 and 87% of the variation in grain yield and protein content, respectively. The calibrated models were used to recommend Npi for the target protein content of 6.8%, with FW and SPAD measured for each plot in 2005. The recommended N rate treatment was characterized by an average protein content of 6.74%(similar to the target protein content), reduced the coefficient of variation in protein content to 2.5%(compared to 4.6% of the fixed rate treatment), and increased grain yield. In the recommended N rate treatments for the target protein content of 6.8%, grain yield was highly dependent on FW and SPAD at PI. In conclusion, the models for N topdressing rate recommendation at PI were successful under present experimental conditions. However, additional testing under more variable environmental conditions should be performed before universal application of such models.

• The Korean Journal of Pesticide Science
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• v.14 no.2
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• pp.95-103
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• 2010

Fomesafen is a selective herbicide, and used to control annual and perennial broad-leaf grass on soybean and fruit fields in USA and China, but not introduced in Korea yet. So, MRL (Maximum Residue Level), and analytical method of fomesafen were not establishment in Korea. Therefore, this experiment was conducted to establish a determination method for fomesafen residue in crops using HPLC-UVD/MS. Fomesafen residue was extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and dichloromethane partition was followed to recover fomesafen from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The fomesafen was quantitated by HPLC with UVD, using a Shiseido CAPCELL-PAK UG C18 column. The crops were fortified with fomesafen at 3 levels per crop. Mean recovery ratio were ranged from 87.5% for a 0.4 ppm in hulled rice to 102.5% for a 0.4 ppm in apple. The coefficients of variation were ranged from 0.6% for a 2.0 ppm in hulled rice to 7.7% for a 0.04 ppm in green pepper. Quantitative limit of fomesafen was 0.04 mg/kg in representative 5 crop samples. A LC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of fomesafen in agricultural commodities.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.19-30
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• 2019

Objective of this study was to develop an organic fertilizer utilizing domestic livestock horn meal and to investigate the application effect of rice and eggplant. The possibility of utilization of livestock horn meal as an organic resource to replace imported expeller cake fertilizer was examined. In order to select domestic organic resources with high nitrogen content, 8 kinds of organic matter such as chicken manure, fish meal, soybean meal, sesame meal, perilla meal, blood meal, livestock horn meal, and beer sludge were analyzed and organic resources with high nitrogen content were selected. In addition, the conditions for the production of organic fertilizers that can be used in organic agriculture were established by mixing of the rice husk biochar and the rice bran as the supplements with the raw materials for mixing ratios. The content of total nitrogen (T-N) in the livestock horn meal was 12.0 %, which was the next low in 13.5 % blood meal. The content of total nitrogen was 5.9 ~ 7.9 % in fish meal and oil cakes. Total nitrogen content of non-antibiotic chicken manure for organic farming was 3 % and nitrogen content in beer sludge was 3.5 %. Organic fertilizer was produced by using biochar, rice bran as a main ingredient of non-antibiotic chicken manure, livestock horn meal and beer sludge. Compared to nitrogen content (4.0 to 4.2 %) of imported expeller cake fertilizer (ECF), the nitrogen content of organic fertilizer utilizing domestic livestock horn meal is as high as 7.5 %. The developed organic fertilizer is met as Zn 400 mg/kg, Cu 120 mg/kg the quality of organic agricultural materials such as or less. To investigate the effect of fertilizer application on the crops, prototypes of developed organic fertilizer were used for the experiment under selected conditions. As a result of application the developed organic livestock horn meal fertilizer (LHMF) for cultivation of the rice and eggplant, the application quantity of the developed organic LHMF 100 % was decreased by 40 % compared to that of the mixed expeller cake fertilizer (MECF). The application of LHMF, which refers to the application rate corresponding to the nitrogen fertilization recommended by the soil test, was reduced by 40% compared to the application rate of MECF, but the same results were obtained in crop growth and yield. The selection of a new high concentration nitrogen source utilizing domestic organic resources and the development of organic fertilizer is the starting point of the research for substitution of imported ECF using domestic local resources at the present time that the spread of eco-friendly agriculture is becoming increasingly important. If it is expanded in the future, it is expected to contribute to the stable production of eco-friendly agricultural products.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.452-460
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• 2017

Rice fields are important stopover sites for the conservation of shorebirds during long-distance migration. These fields serve as food sources providing energy for the next leg of the journey. Shorebirds are able to change their preferred food source at stopover sites. However, the type and distribution of food resources remain unknown for the shorebirds in the Republic of Korea. Therefore, we studied the type and distribution pattern of food resource (macroinvertebrates, remaining rice, and other seeds) for shorebirds in the rice fields. We have identified potential and actual food sources for shorebirds in the rice fields. The potential food sources were collected by using a core-sampling method and the actual food source was ascertained by observational analysis. As a result, a total 19 species of benthic macroinvertebrates in 15 families were recorded as potential food sources. A total of 9 families in 9 orders of benthic macroinvertebrates known to be actual food sources were also recorded during the study period, including loaches, and a tuber of sea club rush. Also, the distribution of the food source depended on soil conditions generated by cultivation such as plowing, harrowing, and the use of pesticides. In the present study, we identified the type and distribution of food sources for shorebirds. This information can be used as essential primary baseline data for conservation of shorebirds using the rice fields of the Republic of Korea.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.303-307
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• 2008

We bred a new green-kerneled glutinous rice variety that can be cultivated in the whole area of Korea, because only one native green-kerneled glutinous rice cultivar, "Saengdongchalbyeo", has been cultivated in the southern coastal area due to its late heading. The seeds of "Saengdongchalbyeo" were irradiated with 200 Gy of gamma ray in 1995. A promising mutant variety, "Nogwonchalbyeo" ("Wonnong 17") was selected through line selection and regional yield trials. In particular, the new variety revealed at the earlier mid of August compared to that of "Saengdongchalbyeo", the early of September, and it was considerably tolerant to a field lodging due to its shortened culm length. Also, "Nogwonchalbyeo" had a higher ripened grain ratio and 1,000 grain weight compared to the original variety. The brown grain yield of the new variety was about 5.40 MT/ha, which was 11.3% higher than that of the original variety, in the regional yield trials at 3 different fields during 2000~2001. The brown and milled grains of the new rice variety contained 20 to 65% higher amount of total amino acids, respectively than that of the original and two checks. For chlorophyll -a, -b and total chlorophyll, the new variety showed nearly two-fold higher than the checks, and for the carotenoid, it had 5.3 - 7.6 times higher amount. These results showed that the new variety can be cultivated as a special green-kerneled glutinous rice with high functional compounds.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.15-26
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• 2012

For stable and sustainable crop production, understanding the effects of climate changes on agricultural water resources is necessary to minimize the negative effects which might occur due to shifting weather conditions. Although various studies have been carried out in Korea concerning changes in evapotranspiration and irrigation water requirement, the findings are still difficult to utilize fordesigning the demand and unit duty of water, which are the design criteria of irrigation systems. In this study, the impact analysis of climate changes on the paddy water demand and unit duty of water was analyzed based on the high resolution climate change scenarios (specifically under the A1B scenario) provided by the Korea Meteorological Administration. The result of the study indicated that average changes in the paddy water demand in eight irrigation districts were estimated as -2.4 % (2025s), -0.2 % (2055s), and 3.2 % (2085s). The unit duty of water was estimated to increase on an average within 2 % during paddy transplanting season and within 5 % during growing season after transplanting. This result could be utilized for irrigation system design, agricultural water resource development, and rice paddy cultivation policy-making in South Korea.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.87-91
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• 2011

Eco-efficiency which is calculated by dividing economic productivity by the environmental load was made by synthesizing eco and efficiency from ecology and economy, proposed by World Business Council for Sustainable Development in 2000. Eco-efficiency by connection of resource efficiency with resource intensity is used as an indicator for evaluating green growth for minimizing the impact on the environment and achieving economic development as well by means of efficient use of resources. This research analyzes eco-efficiency with the case of organic agriculture promoted as a key green growth policy. Thirty questionnaires for farmers producing organic rice in Hongseong-gun, Choongcheongnam-do were used for the analysis. Eco-efficiency was measured by means of the amount of used nitrogen with respect to the amount of income, and was represented that organic agriculture was 32.0 higher than conventional agriculture. The analytical result of technical efficiency, using the (Data Envelopment Analysis (DEA) model showed that it is 0.765 which has a possibility of 21% in management improvement, and higher eco-efficiency was with higher technical efficiency. The analytical results showed that an organic agriculture contributes to green growth more than conventional agriculture. In addition, higher technical efficiency groups exhibited higher eco-efficiency indices.

• Environmental and Resource Economics Review
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• v.25 no.1
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• pp.27-60
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• 2016

An integrated assessment model of climate and the economy (IAM) has been a standard tool for the economic analysis of climate change and policy recommendations. Since policy measures to address climate change take places at a national level, a regional integrated assessment model of climate and the economy (RIAM) is gaining more importance. A RIAM is a useful tool for the assessment of regional (or national) impacts of climate change. This paper investigates the main features of the currently available RIAMs. The focus is social welfare functions and the regional aspects of climate change. The comparative analysis shows that there is a huge gap between the economics of climate change and its applications to RIAMs. As an application, this paper examines the effect of social welfare functions on optimal solutions of the RICE (Regional Integrated model of Climate and the Economy) model. It is found that optimal climate policy such as carbon tax or emissions control rate is very sensitive to the assumptions on social welfare functions of RIAMs. It is better for each country to have their own RIAM as a basic tool for national climate policy-making and for international bargaining in greenhouse-gas mitigation. This is because a country's own preferences such as efficiency, equity, and sustainable development as well as national circumstances can be reflected in RIAM. The Republic of Korea has not developed its own RIAM yet. The comparative analysis and the numerical model in this paper can be a stepping stone for the development of such a national model.

• Korean Journal of Weed Science
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• v.31 no.4
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• pp.375-383
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• 2011

This experiment was carried out to confirm characteristics of macro granule (GG) for herbicidal efficacy by using remote-controlled aerial application (RCAA) to control annual and perennial weeds in rice paddy field, and phytotoxicity to rice and non target plants of formulation types. Herbicidal efficacy of GG applied by using RCAA was 93.6~96.6% in flooded direct sowing cultivation. There was no difference in phytotoxicity between the hand and the power applicator methods in terms of height, number of tiller and yield component. Herbicidal efficacy of GG applied by using RCAA was 92.7~97.3% in machine transplanting rice field. There was no difference in phytotoxicity between the hand and RCAA methods in terms of height, number of tiller and yield component. When suspension concentrate (SC) and GG were applied directly on Chinese cabbage, lettuce, cucumber, pepper, soybean and wild sesame, several symptoms of injury such as, the inhibition of growth, yellowish, leaf fall and withering was observed.