• Advances in environmental research
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• v.12 no.1
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• pp.51-64
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• 2023

The sustainable management of rice straw is essential for protection of human health and environment. This study assesses the impact of stock density of earthworm (Eisenia fetida) and Neem leaves (Azadirachta indica) on the quality of the final vermicompost. The vermicompost is produced using different combinations of rice straw, Neem leaves, and cow dung (bulking agent) by varying stock density of earthworms. The vermicomposting experiments are performed in plastic containers (32 cm × 28 cm × 28 cm) in open for 90 days under laboratory conditions. The stock density of the earthworm is found to be an important factor to influence nutritional quality of the final vermicompost. There is observed significant improvement in the total nitrogen (91.8%), phosphate (73.4%), potassium (38.8%), and calcium (59.05%) content of the vermicompost produced with the highest stock density of the earthworms. All the treatments showed decrease in TOC and C:N content after 90 days of vermicomposting. The treatment with Neem leaves showed maximum growth of earthworms (2.65 fold). Neem leaves brought positive changes in the quality of final vermicompost by enhancing the growth and reproduction of the earthworms. The calcium content increased by 39% in the final vermicompost with the addition of Neem leaves at the same stock density of the earthworms. The stock density of the earthworms and Neem leaves are found to significantly improve quality of the final vermicompost as compared with the compost (control). The surface morphology in SEM images showed high degree of fragmentation in the vermicompost as compared with the compost. The combined action of microbes and earthworms resulted in high degree of disintegration in the vermicompost.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.357-366
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• 2022

Biochar can be obtained by using various types of biomass under an oxygen-limited condition. Biochar can be utilized for various applications such as soil improvement, waste management, growth promotion, and adsorption. Wood vinegar is produced by the process of pyrolysis wood biomass and is used as a growth promoter, for soil improvement, and as a feed additive. When wood vinegar is treated on soil, it acts to control soil pH, improve nutrient availability, and alleviate N₂O and NH₃ volatilization. The objective of this study was to evaluate the effect of biochar and wood vinegar on the growth of perilla and soil quality. The experiment was conducted by using a Wagner pot (1·5,000 a^-1) in a glass greenhouse. The biochar was produced by pyrolysis at 450℃ for 30 minutes using rice husk and rice straw. Wood vinegar was diluted to 1 : 500 (v·v^-1) and used in this experiement. In the results of a cultivation experiment, co-application of biochar and wood vinegar enhanced the growth of perilla. In particular, rice husk biochar affected the leaves of the perilla, and rice straw biochar influenced the stems of the perilla. In addition, soil quality after treatment with biochar and wood vinegar applied together was highest compared to other units. Therefore, it is anticipated that co-application of biochar and wood vinegar will be more productive and improve soil quality compared to individual utilization of biochar and wood vinegar.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.105-110
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• 2011

BACKGROUND: In this study, 5 different treatments such as non-treatment, mixed expeller cake 1.0 N (standard nitrogen fertilizer), rice straw, rice straw+mixed expeller cake 0.5 N, rice straw+mixed expeller cake 1.0 N were performed over 4 cropping seasons over 2 years in order to identify the optimal application rate of mixture of rice straw and mixed expeller cake, organic source in organic cultivation of tomatoes. METHODS AND RESULTS: There was no difference in all treatments in case of 200 mg/kg in the nitrate nitrogen content in soil prior to the first cropping season test under the criteria for nitrogen nutrient based on yield of crops, cultivation without fertilizers seems possible. But in the second cropping season, no treatment and rice straw showed the reduction of yield and in the third cropping season, rice-straw+mixed expeller cake 0.5 N treatment showed the significant difference. The content of nitrate nitrogen in soil prior to cropping seasons was evaluated in 160 mg/kg and standard fertilization such as mixed expeller cake, source of nitrogen, are needed due to the deficiency of nitrogen. In terms of application of organic resources, rice straw showed the effects of improvements on physical properties of soil such as bulk density, cation exchange capacity and humus contents, but the mixed expeller cake did not show any significant differences in improvements on physical properties of soil. CONCLUSION(s): Fertilizer management in organic cultivation of tomatoes is thought to produce the reliable quantity of crops as well as keep the high quality of soils by using the optimal application rate of mixed expeller cake according to the contents of nitrate nitrogen in soil and rice straw which improves the physical properties of soil.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.91.2-92
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• 2003

In order to elucidate influence of nutritional status on rice brown spot caused by Cochliobolus miyabeanus, rice cultivation soils and rice straws were collected from paddy fields where ice brown spot occurred severely, moderately, a little and none respectively. Rice plant materials were analyzed to measure inorganic nutrients in rice straws and rice seeds. Analysis of chemical properties of rice paddy soil showed that EC and contents of available phosphate, cation and silicic acid in soil with severe infections were lower than those in healthy soil. This result suggests that amount and holding capacity of nutrient contents in soils collected from paddy field with infection of C. miyabeanus are relatively low compared to those in soils collected from healthy paddy field. Analysis of inorganic nutrients in rice straws showed that amount of macronutrient elements such as silicic acids, available phosphate and total nitrogen, and micronutrients such as copper, iron and zinc in rice straws from paddy field with infection were lower than those in healthy soil. Especially amount of iron and silicic acid were very low in rice straws from paddy field soils with infection Amount of inorganic nutrients such as iron and zinc in rice seeds was the same trend as those of rice straws. These results showed that one of major factors affecting rice brown spot was amount of nutrient contents in soil and rice straw.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.184-184
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• 2017

Organic matter is very important and essential factor to maintain productivity of paddy field. But as meat consumption and the demand of grain increase, the demand of forage also increased gradually in Korea. So the amount of organic matter in paddy field have been declined gradually by the reduction of return of rice straw for the forage use for cattle. There is not enough alternative resources for forage, we guess this trend of organic matter decline in paddy field would continue for the time being in Korea. So this study was performed to confirm the variation of organic matter and change of rice yield to select suitable rice cultivars which yield reduction is small in condition of organic matter decrease in paddy field. To confirm the change of rice growth and yield in condition of organic matter decrease in paddy field, we transplanted 10 rice cultivars which yield reduction are small in low fertilizer condition. We transplanted it Buan where double cropping of winter barley continues several years on June 10. Planting density were $70plants/3.3m^2$ Fertilizer amount was $N-P_2O_5-K_2O=9-4.5-5.7kg/10a$ and fertilizer split application of nitrogen was basal-tillering stage-panicle initiation = 50-20-30%. And in the other cultivation management, we observed rice standard culture of NICS. In paddy field where withdraw straws of barley and rice, the organic matter content showed tendency to decrease as the years go on. During rice cultivation season, organic matter decreased little by little, but it increased again after rice harvest season. Rice yield was more in order of Sodami, Chunghaejinmi and Saenuri. We judge that there is an advantage in rice yield of rice cultivars which have later heading date because of suitable ripening temperature. Although Sobibyeo and Shindongjinbyeo showed high yield, head rice yield decreased severely owing to chalky and cracked rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.77-84
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• 2005

Three new rice farming systems, i.e. (1) straw-mulched no-till rice cropping system(SMNTRCS), (2)straw-mulched no-till rice-vetch cropping system (SMNTRWCS), (3)conventional rice-barley cropping system(CRVCS) have been established and compared with (4)conventional rice cropping system(CRCS). Grain appearance of brown rice of Korean native rice cultivars in SMNTRCS and SMNTRVCS were better than those in CRBCS and CRCS. Grain appearance of milled rice in SMNTRCS was better than those of other cropping systems. Korean native rice cultivars showed more white belly and broken rice than those of recommended rice cultivars. Mg and K contents of Korean native rice cultivars were the highest in SMNTRVCS. Protein contents of all the cultivars tested were the highest in SMNTRCS. Protein contents of Korean native cultivars were higher than those of recommended cultivars. Amylose contents of the cultivars tested were from 16 to 22 percent, while those of Aedal and Jenmjo were significantly higher than those of the other cultivars. Alkali digestibility values(ADV) of milled rice grain, tested in $1.2\%$ potassium hydroxide for 23 h at $30^{\circ}C$, showed varietal differences and the cultivars grown in CRBCS were the highest and the lowest in CRCS.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.27-35
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• 2012

Various Best Management Practices (BMPs) have been suggested to reduce Nonpoint source pollutant loads from agricultural fields. However, very little research regarding water quality improvement with sediment trap has been performed in Korea. Thus, effects of sediment trap were investigated in this study. Three sediment traps were installed at the edge of six plots and flow and water quality of inflow and outflow were monitored and analyzed. It was found that approximately 64.1 % of flow reduction was observed. In addition, pollutant concentration of outflow was reduced by 39.0 % for $BOD_5$. For SS, $COD_{Mn}$, DOC, T-N, T-P, approximately 62.1 %, 43.4 %, 43.5 %, 40.0 %, and 41.2 % reduction were observed, respectively. Over 80 % and 90 % of pollutant loads were reduced from sediment trap #2 and #3 because of less outflow from plots covered with rice straw/straw mat. In case of intensive rainfall events occurred from July 26~29, 2011, over 60 % of pollutant and 88.9 % of sediment reduction were observed from sediment trap #3. As shown in this study, small sediment traps could play important roles in reducing pollutant loads from agricultural fields. If proper management practices, such as rice straw/straw mat, are used to protect surface from rainfall impacts and rill formation, much pollutant reduction could be expected.

• The Korean Journal of Community Living Science
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• v.17 no.2
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• pp.105-112
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• 2006

The biodegradability test of bulking agents in feces composting process is conducted to increase the management efficiency for environment-friendly rural toilet developed by National Rural Resource Institute in 2001. In the case study through references and field study, ash, fallen leaves, and wood chips are commonly used in the ecological toilet. Extension officers and farmers prefer rice straw, fallen leaves, and chaff among the rural resources as a bulking agents in the aspect of getting and storage as the result of questionnaire survey. As the result of biodegradability test including the temperature change, $CO_2$ gas production, and C/N ratio change of composting pile under the condition of aerobic composting apparatus, rice straw and chaff are good bulking agents for environment-friendly rural toilet. It is recommended that easy getting materials among the above mentioned materials are used for bulking agents as the region and season in environment-friendly rural toilet.

• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.214-225
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• 2018

Rice straw is the principal forage for Korean cattle. Limited supply of domestic forage forces Korea to depend on imported forage. Utilizing locally available domestic feed as an alternative would lead to self-sufficiency and stability in cattle farm management. Locally available feed can be utilized as forage. The challenge of collecting local feed has been overcome by machines that have been developed to harvest feed. Local feed can be completely consumed in the production regions, thus reducing transportation costs and increasing price competitiveness. Hitherto, studies have focused on feed technologies and price competitiveness, among other factors, while the substitution of forage has not been examined. This study conducts a quantitative analysis to estimate the extent to which local feed can replace existing forage. We find that local feed is cheaper, and abundantly available, and can thus replace high-quality forage.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.136-143
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• 2002

Emission of methane and nitrous oxide affected by nitrogen fertilizer materials were measured simultaneously in rice paddy fields under flooding and intermittent irrigation in 2000. Studies focused on mitigating $CH_4$ emission from rice paddy fields are summarized and the possibilities and limits applied to world's rice cultivation are discussed. The mitigation options are water management, soil amendments, organic matter management, different tillage, rotation, and cultivar selection. Altering water management, in particular promoting midseason aeration by short-term drainage, is one of the most promising strategies, although these practices may be limited to the rice paddy fields where the irrigation system is well prepared. The test site was divided into two water managements: a continuously flooded plot which was maintained flooded by constant irrigation from May to September, and an intermittently drained plot in which short-term (20days) draining practices were performed one times during the flooding period. By total emission of GHGs converted by global warming potential (GWP), flooding plots were higher 170$\sim$208% than interimittent irrigation plots. For emission of GHGs in fertilizer materials, it was high in the order of Swine slurry>Urea+Rice straw>Urea>LCU. Basing on GHGs emission of urea fertilization under flooding as baseline GWP of urea fertilization and Latex-coated urea under intermittent irrigation showed lower GHGs emission by 41.4% and 55.8 respectively. In this case fertilizer use efficiency (kg unhulled rice/ of applied N) were 18.2$\sim$20.2 and 18.7$\sim$19.0 and 9.3 and 5.8$\sim$6.6 for Swine slurry and LCU and Urea+Rice straw and Urea in the continuously flooded and intermittently drained plot.