• Korean Journal of Weed Science
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• v.11 no.2
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• pp.122-127
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• 1991

The allelopathic effects of rice and barley straws on lettuce germination and weed growth were investigated. The grinded straw of rice significantly inhibited lettuce germination. Both rice and barley straws decreased weed growth when they were used as a mulch in the field. Rice straw mulch applied with 500g/$m^2$ and 700g/$m^2$ decreased dry weight of Alopecurus aequalis more than 35%. Barley straw mulch applied with 200 g/$m^2$ inhibited dry weight of Echinochloa curs-galli and Digitaris sanguinalis, while the straw applied with 300 g/$m^2$ decreased those by 97%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.302-305
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• 1991

Six low-molecular-weight organic acids from decomposing plant residues were analyzed, which were formic, acetic, succinic, malic, tartaric, and citric acids. Straws of rice, barley, wheat, and rye were put under acid- hydrolysis after decomposition for different periods of time. The contents of organic acids in the hydrolysates were determined. 1. The relative molarity of a low-molecular-weight organic acid varies with the passage of the time of decomposition. 2. In general, formic and acetic acids were the major low-molecular-weight organic acids in all samples. 3. Malic acid was found to be only in a trace amount in rice and barley straws, and in their decomposed residues. 4. The relative molarities of total monocarboxylic acids(formic and acetic) increased with the progressing time of decomposition, far exceeding those of dicarboxylic and tricarboxylic acids combined together. 5. Formic and acetic acids were compensatory for each other and they were supposed to persist for a long time in soil environment.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.476-480
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• 2005

Agricultural straws such as rice and barley were used as partial replacement of raw materials for particleboard (PB) manufacture. A melamine-urea-formaldehyde (MUF) resin, based on 5 percent melamine addition of the resin solids weight, was synthesized in the laboratory for the bonding of PB. PBs were made using two straw particles based on 10, 20, 30, 40% oven dry weight addition with MUF resin. PBs were tested for physical and mechanical properties, and water soak dimensional stability. The results indicated that as rice and barley straws addition level were increased, the properties of IB, MOR and dimensional stabilities such as thickness swell and water absorption were decreased. Overall, the agricultural straws can be used at 15% substitution of raw materials for PB manufacture.

• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.111-116
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• 2015

Combined applications of rice bran with pine leaves were tested to examine the inhibitory effects to paddy weeds and increased yield of rice for developing techniques of environment-friendly weed management in paddy rice fields. Weed control efficacy at 60 days after treatment was improved to 88.8% by combined application of rice bran with pine leaves, while weed control efficacy by single application of rice bran showed 67.5%. The other weed control efficacy combined with chestnut leaves and barley straws were 76.3% and 69.9% respectively. Combined application of rice bran with pine leaves was more effective to broadleaf weeds such as Monochoria vaginalis. Weed control efficacy by combined application with pine leaves was 100% until 70 days after rice transplanting and maintained weed control effect up to 90 days after transplanting. Rice yield by combined application of rice bran with pine leaves was 526 kg/10 a, which was higher yield than by combined application with barley straws, single application of rice bran, natural snail application and hand weeding.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.75-82
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• 2016

Objective of this experiment was to predict the potential methane production with crop residues at different loading rates. Anaerobic digestion of barley and rapeseed straw substrates for biogas production was performed in Duran bottles at various biomass loading rates with crop residues. Through kinetic model of surface methodology, the methane production was fitted to a Gompertz equation. For the biogas production at mesophilic digestion with crop residues, it was observed that maximum yield was 37.2 and 28.0 mL/g at 6.8 and 7.5 days after digestion with 1% biomass loading rates of barley and rapeseed straws, respectively. For the methane content of mesophilic digestion, there were highest at 61.7% after 5.5 days and 75.0% after 3.4 days of digestion with barley and rapeseed straw on both 5% biomass loading rates, respectively. The maximum methane production potentials were 159.59 mL/g for 1% barley straw and 156.62 mL/g for 3% rapeseed straw at mesophilic digestion. Overall, it would be strongly recommended that biomass loading rate was an optimum rate at mesophilic digestion for using 1% barley and 3% rapeseed straws for feed stocks.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.241-250
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• 2003

Accurate and rapid evaluation of the nutritional quality of Korean straws is important because of the recent increase in the use of these feedstuffs in Korean. The aim of the study was to establish with relationships between ruminal fermentation of Korean straws and in vitro gas production using a pressure transducer. The pressure transducer system includes pressure censors, AD board, LED monitor, and the computer with real-time graphics. Both gas production and DM digestibility data were fitted into the exponential equation P = a + b (1-e-$1-e^{-ct}$). The initial rate of gas production was highest for rice straw, followed by barley straw and wheat straw. The gas production rate of constant (c) in gas production for rice straw, wheat straw, and barley straw were 3.8, 2.5, and 2.5 $%h^{－1}$, respectively. Total VFA concentration (mM) produced after 72h incubation was similar among three Korean straws, even though was variable during the early (12h) fermentation. Volume of gas production was related (P> 0.05: r = 0.76 to 0.83) to DM disappearance and also strongly related (p< 0.05: r = 0.91 to 0.98) to VFA concentration at all incubation times. Linear correlation showed between gas production and DM disappearance and VFA by in vitro will be matched in in vivo digestibility.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.13-16
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• 1998

A $2{\times}2{\times}4$ factorial study was conducted to examine the possibility of improving estimates of in vitro digestibility, using untreated (UBS) and ammonia-treated (ABS) barley straw, through homogenization of rumen fluid (RF) and by additions of urea (U) and casein (C) as N sources and Xylose + Glucose (XG) as energy sources into artificial saliva. Digestibiltiy of ABS was significantly greater than that of UBS (p < 0.001). There was a significant decrease in digestibility when additions (U, UC, UCXG) were compared with the control (p < 0.001). A 2-way interaction between RF and straw type was significant (p < 0.05) for dry matter digestibility (DMD). Homogenization of RF increased DMD of ABS (p < 0.05) whereas it decreased DMD of UBS (p > 0.05). The study showed that addition of N alone or in combination with energy sources was not better than control, rather the reverse, digestion was inhibited by a combination of U and casein (UC). It was concluded that sufficient N and branched chain fatty acids were supplied in the inoculum from sheep fed high protein grass cubes to support the growth of cellulolytic microbes during in vitro incubation. Further studies are, however, required to explore the potential of homogenization in improving the in vitro method to estimate digestibility of cereal straws.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.414-422
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• 2022

The objective of this work was to investigate the feasibility of acid-catalyzed hydrothermal fractionation for maximum solubilization of the hemicellulosic portion of two typical agricultural residues. The fractionation conditions converted into combined reaction severity (CS) in the range of 1.2-2.9 was used to establish a simple reaction criteria at glance. The hemicellulosic sugar yield of 56.6% was shown when rice straw was fractionated at the conditions at the conditions; 160 ℃ of temperature 0.75% (w/v) of H₂SO₄, 20 min of reaction time, 1:15 solid/liquid ratio. The hemicellulosic sugar yield of 83.0%, however, was achieved when barley straw was fractionated at the conditions at the conditions; 150 ℃ of temperature 0.75% (w/v) of H₂SO₄, and 15 min of reaction time, 1:10 solid/liquid ratio. For barley straw, acid-catalyzed hydrothermal fractionation could be effectively performed. After the fractionation process, the remaining fractionated solids were 48.5% and 57.5% from raw rice and barley straws, respectively. The XMG contents in the solid residues decreased from 17.3% and 17.6% to 6.0% and 2.6%, which corresponded to 16.7% and 8.5% on the basis of the raw straws, respectively. In another way, only 5.6% of cellulose and 8.5% of XMG were lost due to excessive decomposition during the acid-catalyzed hydrothermal fractionation of barley straw, compared to cellulose and XMG losses of 6.4% and 26.6% in rice straw. Hemicellulosic sugars from the rice straw were considered more over-decomposed due to the somewhat higher reaction severity at the acid-catalyzed hydrothermal fractionation.

• Microbiology and Biotechnology Letters
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• v.1 no.1
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• pp.31-36
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• 1973

A method for acid-hydrolysis of agricultural wastes and its utilization was investigated. In order to obtain fermentable sugar solution from cellulosic wastes such as cereal straws and hulls, in particular, of rice, barley and wheat, the chemical compositions were analyzed and optimum conditions of hydrolysis determined. The cereal straws contain 42 to 55 % of crude cellulose including hemicellulose. On the hydrolysis with 1% of sulfuric acid at 40 psig, 35.6% of the reducing sugar based on the weight of dry matter was formed from rice straw, (variety Chinheung) in 30 min. More powerful condition of hydrolysis would appear to decompose the sugar formed into other compounds, for instance, furfural. Under atmospheric pressure with 5% of the acid, rice straw was hydrolyzed to 35% of reducing sugar content in 3 hours. Candida utilis could assimilate the sugars in the hydrolyzate up to more than 97%, and a yield of the yeast cells reached 55% to the utilized sugars.