• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.783-791
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• 2019

Objective: This study was to evaluate the fermentation dynamics, structural and nonstructural carbohydrate composition and in vitro gas production of rice straw ensiled with lactic acid bacteria and molasses. Methods: Fresh rice straw was ensiled in 1-L laboratory silos with no additive control (C), Lactobacillus plantarum (L), molasses (M) and molasses+Lactobacillus plantarum (ML) for 6, 15, 30, and 60 days. After storage, the silages were subjected to microbial and chemical analyses as well as the further in vitro fermentation trial. Results: All additives increased lactic acid concentration, and reduced pH, dry matter (DM) loss and structural carbohydrate content relative to the control (p<0.05). The highest organic acid and residual sugar contents and lignocellulose reduction were observed in ML silage. L silage had the highest V-score with 88.10 followed by ML silage. L and ML silage improved in vitro DM digestibility as compared with other treatments, while in vitro neutral detergent fibre degradability (IVNDFD) was increased in M and ML silage (p<0.05). M silage significantly (p<0.05) increased propionic acid (PA) content and decreased butyric acid content and acetic acid/PA as well as 72-h cumulative gas production. Conclusion: The application of ML was effective for improving both the fermentation quality and in vitro digestibility of rice straw silage. Inclusion with molasses to rice straw could reduce in vitro ruminal gas production.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.744-748
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• 2012

This study was carried out to investigate the incorporation effect of green manure crops (GMC) such as the hairy vetch on improvement of soil environment in reclaimed land during sorghum${\times}$sudangrass hybrid (SSH) cultivation over the past three years from 2009 to 2011. Plots consisted of conventional fertilization (CF) and incorporation of GMC were divided by rates of additional nitrogen fertilizer ($100kg\;ha^{-1}$) and decreased percentage of 30 50 70 100 fertilization in addition to non nitrogen fertilization (NNF). Soil physico-chemical properties, growth and yield potential were examined. The results were as follows. The testing soil was showed strong alkaline saline soil with low organic matter contents and less available phosphate while exchangeable sodium and magnesium were higher. Soil salinity was increased during cultivation of summer crop. However, SSH was not affected by salt content. The fresh weight of GMC at incorporation time was $18,345kg\;ha^{-1}$. Content of total nitrogen at incorporation time was 3.09% and the C/N ratio was 12.8. Fresh and dry matter yield of SSH were higher in the order of 30%, CF, N50%, N70%d, N100%, and NNF. Fresh and dry matter yield of SSH increased in the order of CF ($55,050kg\;ha^{-1}$, $16,250kg\;ha^{-1}$), N contents from 30% to 9%. Soil physical properties, such as bulk density were decrease with incoporation of GMC, while porosity was increased. Soil chemical properties, such as pH was decreased while content of exchangeable calcium, available phosphate, and organic matter were increased. Also contents of exchangeable sodium and potassium were decreased with incorporation of GMC than those before experiment. Thus, we assumed that incorporation of hairy vetch was more effective that can lead to reduce chemical nitrogen fertilizer and to improve soil environment in cultivating SSH on Saemangeum reclaimed land.

• Korean Journal of Organic Agriculture
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• v.14 no.1
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• pp.55-67
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• 2006

A survey of 31 organic farmers were conducted to investigate the actual conditions of organic matter application. The amounts of organic matter application in the fields were higher in order of fruit, vegetable and rice farm. The average was 50 ton/ha in vegetable farms. In the green vegetable farms saw dust and animal manure were mainly utilized to make compost. Rice straw, wood chip, and forest bushes were also used for composting. In the fruit vegetable farms materials relatively lower in nitrogen content such as rice straw and cattle manure were used in vegetative period and materials higher in nitrogen content such as oil cake and wild grass were used in reproductive phase. Nutrient balance investigated in the farm in Icheon region who produce lettuce, angelica, and kale continuously in one cropping year indicated surplus in three major nutrients. Nitrogen and phosphorous were in excess by 29 and 10 kg respectively in the organic rice farm in yang-pyoung region. While soil chemical properties in the organic farms are within the adequate range in open field, it is much higher than the limits in the greenhouse soils. Overall application of organic matter is in an oversupply state. This results suggested that the organic matter management should be based on the soil conditions for sustainable cultivation. Chemical composition of organic matters and soil test reports should be considered prior to the application of organic matter.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.1
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• pp.5-11
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• 2022

This research evaluated the long-term application effects of different soil amendments on yield, dissolved organic carbon, nitrogen and soil organic carbon stock in rice paddy. The experiment consisted of four different fertilizations; Inorganic fertilization (NPK), NPK+Lime (NPKL), NPK+Silicate (NPKS), NPK+Compost (NPKC). There was no significant difference in rice yield between the treatment groups in 1995, but the rice yields in the NPKL and NPKC treatments in 2019 increased by 4.3% and 14.3% compared to NPK. In terms of soil properties, the pH of NPKS(6.7) and NPKL(6.4) in 2019 increased the most compared to the soil pH before experiment(5.2). The organic matter(OM) content from NPKC treatment increased upto 34 and 27 g kg^-1 in year of 1995 and 2019, respectively, compared to before the test. In NPKS and NPKL treatment, labile carbon and nitrogen content, used as a soil quality indicator, increased by 1.1-1.9 times over the control. From these result, it is suggested that type and application rate of soil amendment should be determined based on the soil analysis before cultivation for sustainable agricultural environment and productivity.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.211-215
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• 2015

The hydrolysis of defatted rice bran using near-critical water was performed, and the feasibility of consequent hydrolyzate as a growth medium was investigated by the cultivation of Saccharomyces cerevisiae. The near-critical water hydrolysis was carried out through a series of batch experiments, and the contents of total carbohydrates, disaccharides, and monosaccharides, total organic carbon (TOC), total nitrogen (TN), pH of products were measured. The growth rate of Saccharomyces cerevisiae was measured with optical density. The yield of total carbohydrates, TOC, and TN increased with temperature below $240^{\circ}C$, however, decreased above $240^{\circ}C$. The decrease of yields above $240^{\circ}C$ was caused by the formation of organic acids, and it agreed with the change of pH of products. The yield of glucose was a maximum at $200^{\circ}C$ and it decreased dramatically at higher temperature. The growth rate of Saccharomyces cerevisiae cultivated in the hydrolyzate was similar with that in the commercial medium under certain conditions. The growth rate was correlated with the content of glucose in hydrolyzate.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.196-203
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• 1999

To establish the best rice cultivating system in the aspects of environment-loving agriculture, the amounts and patterns of nitrogen leached in the paddy soil were investigated with 7 treatments; Recommendation(R), Farmer's usual practice(FUP), Straw compost+chemical fertilizers reduced(SCF), Fresh straw+recommendation(FSC), Fresh cow manure(FCM), Cow manure compost(CMC), and no fertilization as Control(C). And SCF, FCM and CMC were applied with same amounts of total nitrogen to R. The infiltrated water samples were collected in ceramic porous cups which were buried at 60cm depth from the top. Concentrations of nitrate-N in irrigated water were $1.3mg\;l^{-1}$ on rice transplanting season when nutrients began to elute from paddy soil, and $0.4mg\;l^{-1}$ after breaking off irrigation. But it was $4-6mg\;l^{-1}$ in rice growing period. The maximum concentration of nitrate-N in leachate was not more than $7mg\;l^{-1}$ during rice cultivation. The amounts of nitrogen leached in R, FUP, SCF, FSR, FCM, CMC and C were 59, 63, 25, 41, 24, 27, $17kg\;ha^{-1}y^{-1}$ respectively. Nitrogen leaching was decreased to about 30% by supplement of fresh rice straw(FSC) to R. Furthermore, it was possible to reduce to over 50% of nitrogen leaching by reducing chemical fertilizer application(CF), or by substituting of chemical fertilizers with fresh cow manure(FCM) or cow manure compost(CMC). In added organic fertilizer treatments, the amounts of infiltrated nitrogen were less $13-46kg\;ha^{-1}y^{-1}$ than that of input by irrigation. This experiment showed that nutrients leaching was minimized by substitution of chemical fertilizers with organic fertilizer or by application of straw with chemical fertilizers in rice paddy soil and rice cultivation with suitable fertilizer management can work as a purifier rather than contaminator of water.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.199-205
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• 2004

The quality characteristics of traditional Korean Takju fermented with discolored, broken, and milled rice were evaluated. Initial pH of medium and culure temperature for the alcohol fermentation were 4.2 and 26$^{\circ}C$, respectively. After 5 days of cultivation, final pH and temperature were 4.0 and 23.5$^{\circ}C$. The alcohol contents in fermentation of discolored and broken rice was about 18.0％ and that of milled rice was 18.7％. The content of succinic acid was highest in organic acid components of products fermented three materials respectively. The major volatiles were 3-methyl-1-butanol, 2-methyl-1-propanol, n-propanol and ethyl acetate. In free amino acid composition of mashes, alanine retained more than 1000 mg％. Free sugars contained in mashes such as glucose, fructose, sucrose, maltose were also analysed by HPLC. Results of sensory evaluation in taste, aroma, color were showed good score above 4.3.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.234-242
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• 2011

BACKGROUND: Cultivation of winter cover crops is strongly recommended to increase land utilization efficiency, animal feeding material self-production, and to improve soil and environmental quality. METHODS AND RESULTS: Four major winter crops (barley, Chinese milk vetch, hairy vetch, and rye) having different C/N ratio were seeded in silt loam paddy soil in the November 2007 and the aboveground biomass was harvested on the late May 2008 to evaluate its effectiveness as green manure, and root biomass distribution was characterized at the different depth (0-60 cm) to study its effect on physical properties and carbon sequestration in soil. During this experiment, the naturally growing weed in the rice paddy soil in Korea, short awn foxtail (Alopecurus aequalis Sobol), was considered as control treatment. Above-ground biomass of all cover crops selected was significantly higher than that of the control treatment (2.8 Mg/ha). Comparatively higher above-ground biomass productivity of rye and barley (15.8 and 13.5 Mg/ha, respectively) suggested that these cover crops possibly had the highest potential as a green manure and animal feeding material. Root biomass production of different cover crops followed the same trend as that for their above ground biomass. Rye (Secale cereal) might have the highest potential for soil C accumulation (7893 C kg/ha) by root biomass development, and then followed by barley (6985 C kg/ha), hairy vetch (6467 C kg/ha), Chinese milk vetch (6671 C kg/ha), and control (5791 C kg/ha). CONCLUSION(s): Cover crops like rye and barley having high biomass productivity might be the most effective winter cover crops to increase organic carbon distribution in different soil aggregates which might be beneficial to improve soil structure, aeration etc. and C sequestration.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.108-113
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• 2022

Arsenic (As) uptake and accumulation from agricultural soil to rice vary depending on the soil environmental conditions such as soil pH, redox potential, clay content, and organic matter (OM) content. Therefore, these factors are important in predicting changes in the uptake and accumulation of As in rice plants. Here, we studied the chemical properties of As-contaminated and/or rice straw compost (RSC)-treated soils, the growth responses of RSC-applied rice plants under As-contaminated soils, the changes in As content of soil, and the relationship between As uptake and accumulation from the RSC-treated soils to the rice organs under As-contaminated soils. Rice plants were cultivated in 30 mg kg^-1 As-contaminated soils under three RSC treatments: 0 (control), 12, and 24 Mg ha^-1. No significant differences were indicated in the chemical properties of pre-experimental (before transplanting rice seedling) soils, with the exception of EC, OM, and available P₂O₅. As the treatment of RSC under 30 mg kg^-1 As-contaminated soils increased, EC, OM, and available P₂O₅ increased proportionally in soil. Increased soil RSC under As-contaminated soils increased shoot dry weight of rice plants at harvesting stage. As content in roots increased proportionally with RSC content, whereas As content in shoots decreased under As-contaminated soil at all stages of rice plants. Nevertheless, As accumulation were significantly decreased in both roots and shoots of RSC-treated rice plants than those in the plants treated without RSC. These results indicate that the use of RSC can mitigate As phytotoxicity and reduce As accumulation in rice plants under As-contaminated soils. Therefore, RSC can potentially be applied to As-contaminated soil for safe crop and forage rice production.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.11
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• pp.1560-1568
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• 2011

This study was conducted to evaluate the yield, nutrient characteristics, ruminal solubility, degradability and disappearance of spent mushroom (Agaricus bisporus) substrates for ruminants. The annual yield of spent Agaricus bisporus substrates was measured to be about 210,000 tons (M/T) in South Korea. The surface soil-removed spent substrates had nutritional characteristics of high crude ash (375 g/kg) and Ca (32 g/kg), medium protein (134 g/kg CP), and high fiber (384 g/kg NDF on a DM basis). Compared with initial mushroom substrates, spent mushroom substrates had twice higher (p<0.0001) CP content and 22.0% lower (p<0.0001) NDF content on an organic matter basis. Compared with raw rice straw, spent rice straw had much higher (p<0.05) predicted ruminal degradabilities and disappearances of DM and CP and a little lower (p<0.05) predicted degradability and disappearance of NDF. In conclusion, the general feed-nutritional value of spent mushroom (Agaricus bisporus) substrates appeared to improve after cultivation of mushrooms.