• Journal of Animal Environmental Science
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• v.12 no.1
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• pp.41-44
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• 2006

Broiler manure has much nutrient that can be used as the organic fertilizer to enhance the fertility of soil. However, if it is used directly without biodegradation of organic materials and destruction of weed seed and harmful bacteria, it can produce the generation of weed and disease of plant. Composting of manure is a biodegradation of organic materials into inorganic materials and humus. To proceed biodegradation of manure effectively and enhance the composting performance, optimum environmental condition for microbial growing should be maintained. Environmental variables which can influence the growing activity of microbes are moisture content, pH, porosity, C/N of the composting materials and oxygen supply quantity. Oxygen and porosity are usually supplied by aeration or mixing of materials. This study was intended to investigate the effect of mixing frequency on the composting performance. Mixing of composting materials was performed by turning the bioreactor up and down by hand without any mechanical energy. The broiler manure was captured from the greenhouse type broiler ham as the compounds of broiler manure and rice-hulls, which were used as the base materials. To compost the compounds of broiler manure and rice-hulls, dairy manure was mixed to get appropriate characteristics of composting material. Composting temperature over $55^{\circ}C$ for killing pathogen and weed seed was maintained for longer period with increase of mixing frequency.

• Journal of Environmental Science International
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• v.25 no.6
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• pp.889-895
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• 2016

In Danseong-myeon (myeon is a subdivision of), Sancheong-gun, and Sugok-myeon, Jinju City, pot seedling culture was used at the rates of 100% and 62%, respectively. Root restriction seedling culture was used relatively more frequently than pot seedling culture in Yangchon-myeon, Nonsan City, Guryong-myeon, Buyeo-gun, and Wolsan-myeon, Damyang-gun. Open-field seedling culture was used at the rates of 80% and 54% in Samnangjin-eup (eup is a subdivision of a gun), Miryang City and Ssangnim-myeon, Goryeong-gun, respectively. In Danseong, Sancheong, and Sugok, Jinju, granite soil was used as the medium for pot seedling culture at the rates of 90% and 80%, respectively. In Yangchon, Nonsan, Wolsan, Damyang, and Ssangnim, Goryeong, commercial bed soil and coir dust were used for seedling culture at the rates of 73%, 64%, and 60%, respectively. At the main production sites, the use of granite soil for seedling culture, highest rate in 2000-2005, continued to decrease; in 2011-2013, granite soil was used at the rate of 37%, while commercial bed soil and coir dust were used at the rates of 32% and 14%, respectively. The bulk density of commercial bed soil, expanded rice hulls, and coir dust was $0.11-0.16g/cm^{-3}$. Coir dust was the lightest material but had the highest and, 36.7% and 21.8%, respectively. In sandy loam soil and granite soil was low. The pH of all growth media was between 5.4 and 7.0, and the values were in the range of $0.15-0.66dS{\cdot}m^{-1}$. However it was necessary, to adjust the pH levels and enhance the of expanded rice hulls, sandy loam soil, and granite soil. Similarly, the fertilizer concentration and air permeability of coir dust need to be adjusted.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.218-222
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• 2003

This study was carried out to find optimum condition through sterilization methods for cultivation of Neutaribeosut (Oyster mushroom). 1. Yield of additive culture of pine sawdust, cotton and rice hulls at bag­cultivation of Neutaribeosut. was similiar to additive culture of pine sawdust, cotton and pulpe as conventional methods. 2. Yield of Neutaribeosut at low temp. sterilization method as 50 to 6$0^{\circ}C$ and 7days treatment was higher about 18 to 19％ than that of high temp. as 121$^{\circ}C$ and 90 minutes treatment. 3. In case of farmer­cost, low than high temperature sterilization method appeared lowly about 12％. So this method will be of advantage to farmers in both yield and farmer­cost.

• Journal of Life Science
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• v.23 no.6
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• pp.757-769
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• 2013

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater, identified as Bacillus velezensis by analyses of 16S rDNA and partial sequences of the gyrA, and designated as B. velezensis A-68. The optimal conditions for production of CMCase by B. velezensis A-68 were established using response surface methodology (RSM). The optimal concentrations of rice hulls and yeast extract, and initial pH of the medium for cell growth were 60.2 g/l, 7.38 g/l, and 7.18, respectively, whereas those for production of CMCase were 50.0 g/l, 5.00 g/l, and 7.30. The analysis of variance (ANOVA) implied that the most significant factor for cell growth as well as production of CMCase was yeast extract. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ in the medium for cell growth were 7.50, 1.00, 0.10, and 0.80 g/l, respectively, which were the same as those for production of CMCase. The optimal temperatures for cell growth and production of CMCase were 30 and $35^{\circ}C$, respectively. The maximal production of CMCase under optimized conditions was 83.8 U/ml, which was 3.3 times higher than that before optimization. In this study, rice hulls, agro-byproduct, were developed as a substrate for production of CMCase and time for production of CMCase was reduced to 3 days using a newly isolated marine bacterium.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.119.2-120
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• 2003

Seed-borne fungal pathogens on rice seeds were investigated in order to evaluate their effect on rice grain quality. Rice seeds of two cultivars, Ilmibyeo and Daesanbyeo were collected from 27 areas of Korea and the fungal parasites on seeds were isolated by using a blotter method. Isolation frequency and number of species were varied from collection areas of seed samples. A total 13 species of fungi were identified from the seeds. Among them, Altemana alternata was the most frequent over the country. Bipoiaris oryzae most commonly from Gyeongbuk and Jeonbuk, Alternaria padwickii from Jeonbuk, and Nigrospora oryzae from Choongnam. However Bipolaris. oryzae, Alternaria padwickii, and Nigrospora oryzae were the most frequently isolated fungi from Gyeongbuk and Jeonbuk, and Chungnam, respectively. B. oryzae, A. alternata, A. padwickii, and N. oryzae were dominants on Ilmibyeo showing 10.3％, 10.2％, 5.2％, and 5.2％ infection rate, respectively. While, N. oryzae, A alternata, and Cladosporium sp. were most frequently isolated fungi from Deasanbyeo revealing 15.1％, 9.6％, and 7.5％ infection rate, respectively. These fungi inhabiting on hulls or endosperms of rice seed might be considered as potential factors decreasing rice grain quality. Further investigation of the fungi on grain rice quality are undergoing.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.599-605
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• 2016

In this study, two experiments were conducted to investigate the physicochemical characteristics (Exp. I) of bedding materials such as rice hulls (RH), sawdust (SD), wood shavings (WS) and sawdust+wood shavings (S+W; 1:1 in volume), and utilization of these beddings except RH (Exp. II) for rearing beef cattle. In Exp. I, the distribution of particle size (%) with $250{\mu}m$ and below $250{\mu}m$ was greater (p<0.05) in SD (30.4) than RH (4.4), WS (18.8) and S+W (20.1). Bulk density ($kg/m^3$) of bedding materials was directly proportional to the percentage of $250{\mu}m$ and below $250{\mu}m$ particles, 178, 46, 112, and 88 for SD, WD, S+W and RH, respectively. Water absorption rate (%) after submersion in water for 24 h was higher (p<0.05) in WS (540.2) compared to SD (270.2), S+W (368.2). The S+W had an intermediate value of the absorption rate between SD and WS, but had an outstanding durability of water absorption capacity. Moisture evaporation rate (%) for 12 h was higher (p<0.05) in WS (75.4) than SD (70.5), S+W (72.2) and RH (57.8). Average ammonia emission ($mg/m^2/h$) for 36 h was higher (p<0.05) in RH (3.15) than SD (1.70), WS (1.63), and S+W (1.73). In Exp. II, thirty six Hanwoo cows were allocated in 9 pens with one side on feed bunk side (Side A) and another side equipped with water supply (Side B) for 3 weeks with duplicated periods. Average moisture concentrations (%) of beddings were higher (p<0.05) in WS (side A, 65.7; side B, 57.9) than SD (side A, 62.5; side B, 52.2) and S+W (side A, 61.6; side B, 50.7). Regardless of types of beddings, moisture concentrations (%) of beddings within a pen were lower (p<0.05) at side B than A, implying longer period of utilization. These results suggest that using S+W would be a better choice than SD or WS alone, considering physicochemical characteristics and economics, and RH is not a suitable material as a bedding for beef cattle.

• Journal of Bio-Environment Control
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• v.10 no.2
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• pp.106-110
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• 2001

In an effort to evaluate the economic value and durability of the expanded rice hull as substrates, changes in the physical and chemical properties of material and plant growth in that substrate were studied. Using and electron microscope, the structure of used and new expanded rice hull substrate was examined. Considerable decomposition was found in the substrate which had been used one to three times. Compactness and lowered porosity in the used substrates were probably caused by decomposition. The results of cation analysis showed the possible destruction of cell wall of rice hulls. Abundant $Ca^{2+}$ in the substrates used for two to three times also indicated the possibility of decomposition. In tomato yield comparison, 15.2% more yield of tomato fruit in a new substrates indicated the negative effects of decomposition of one-time used substrates. Yield decreased in the substrates used for three times. if perlite substrates is used for three years before renewal and the cost of the perlite renewal is counted. 65.3% saving in the cost will be realized with the use of an expanded rice hull substrate. Another positive effect of the expanded rice hull substrate is the decrease of environmental contamination.n.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.316-325
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• 2009

Adequate conditions of water content and aeration of container media are major environmental factors in the production of pot plant. This experiment was carried out to find optimum physical property of media for the production of small potted Ardisia in capillary mat irrigation system. The plant materials used in this experiment were Ardisia pusilla and Ardisia japonica. Seven substrates were formulated by blending perlite or fresh rice hulls at 20%, 40%, 60% (v/v) with sphagnum peat. Total pore space (TPS) increased by blending sphagnum peat with fresh rice hulls, but decreased by blending sphagnum peat with perlite. As fresh rice hull (FRH) and perlite content increased, air filled pore space (AFP) of substrate increased but container capacity (CC) decreased. Substrate blended with fresh rice hull was higher AFP than blended with perlite and the rate of increase was higher for FRH-containing substrate. As AFP increased, the $CO_2$ concentration in the pot decreased and the $CO_2$ concentration of substrate blended with FRH was higher than blended with perlite. The fresh and dry weight of Ardisia pusilla and A. japonica was the highest in the substrate contained 60% FRH, but the ratio of shoot dry weight to root dry weight was the lowest. The optimum total pore space, air-filled pore space, water holding capacity of substrate for the growth of Ardisia pusilla and A. japonica in the capillary mat irrigation system were 82.8%, 25.6%, and 57.2% respectively.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.283-292
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• 1996

This study was performed to determine the physical properties of rice hull and straw which could be used for an optimum design and operation of the handling facilities for these rice crop by-products. The properties measured were kinetic friction coefficient , bulk density, and dynamic and static angle of repose. Rice hulls with moisture content of 13% and 21% were used throughout the test while rice straws of 10% and 16% moisture were chopped into 10mm length and used for the test. Friction coefficient was calculated from the horizontal traction forces measurement when a container holding the mass of rice hull and straw was pulled over mild steel. PVC, stainless steel, and galvanized steel surface by a universal testing machine. Bulk density was measured by an apparatus consisting of filling fundel and a receiving vessel. Dynamic angle of repose which is the angle at which the material will stand when piled was calculated from the photos of bulk samples after they were flowed by gravity and accumulated on a circular surface. Static angle of repose which is the angle between the horizontal and the sloping side of the material left in the container when discharging was also measured in the similar way. Results and conclusions from this study are summarized as follows . 1. Kinetic friction coefficient of both rice hull and straw were in the range of 0.26 -0.52 and increased with the moisture content. The magnitude of friction increased in the order of galvanized steel, stainless steel, PVC ,and mild steel. 2. Bulk densities of rice hull decreased while those of rice straw increased with moisture content increase . Average bulk densities of rice hull and straw were 96.8 and 74.7kg/㎥, respectively. 3. Average dynamic angle of repose for rice straw was 32.6$^{\circ}$ and those for 13% and 21% moisture rice hull were 38.9$^{\circ}$ and 44.9$^{\circ}$ , respectively. 4. Static angles of repose for both rice hull and straw showed increase with the moisture content. The values were 75.2\ulcorner and 80.2$^{\circ}$ for 13% and 21% moisture rice hull, respectively. Rice straws having 10% and 16% moisture content showed 87.3% and 89.2$^{\circ}$ static angle of repose, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.403-410
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• 1996

Variations of temperature and physicochemical environment during composting of a mixtures(2:1, v/v) of cattle manure and rice hulls(CMR) in two different composting methods, static windrow(SW) and aerated static pile system(ASPS), were monitored for evaluating the efficient composting system in greenhouse. The pH of composting materials increased to around 8.9 initially, then decreased and stabilized slowly to the neutral value. Composting materials in ASPS showed a rapid stabilization in pH value from the 4th week comparing to the speed in SW. Thermophilic stage for ASPS Lasted at 3 week whereas 6 weeks for WS. Required time to get thermophilic zone in compost was shorter in ASPS than in WS. Reduction rate in total carbon(T-C) was higher in ASPS than in WS. Organic matter was reduced more rapidly in ASPS than in SW showing 9 percent difference after the 6th week. Total nitrogen(T-N) increased while composting process, showing 9 percent after 6th week in WS and 1.8 percent after 7th week in ASPS. C/N ratio was stabilized after 6th week showing 17 and 21 level in WS and ASPS each. Quantity of ash and mineral content increased during composting in both system, showing higher content in ASPS. Composting process by intermittent, aerated static pile system in greenhouse had a significant effect on the reduction of required period for composting.