• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.16-22
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• 1997

Determination of N mineralization and nitrification potentials of selected Piedmont soils of North Carolina requires a better understanding of the influences of incorporated plant residues. The net N mineralization and nitrification were significantly influenced by the soil types and by plant species. The net N mineralization and nitrification of soils mixed with plant residues were consistently increased with successional incubation periods. The net mineralization and nitrification ranged from $9.77{\mu}g/g$ to $143.80{\mu}g/g$, and from $5.31{\mu}g/g$ to $145.66{\mu}g/g$ during the incubation periods, respectively. The net N mineralization was more influenced by NO3-N than by NH4-N. Overall, the greatest proportions of net N mineralization and nitrification occurred in Chewacla and Wehadkee and lowest in Enon and Mecklenburg. For the plant residues, the net N mineralization and nitrification were observed to be lowest in corn and highest in soybean. In a low-input agricultural systems, soybean may be planted as cover crop which may improve the nitrogen status of selected Piedmont soils of North Carolina.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.4
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• pp.50-56
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• 2008

Aqueous thermal liquefaction of rice, barley, wheat, and rapeseed straws was investigated to compare the amount of heavy oil with catalysts such as $K_2CO_3$, NaOH and KOH in the reaction temperature at $320^{\circ}C$ for 10 minutes. The reaction was carried out in a 5,000ml liquefaction system with dispenser and external electrical furnace. Raw materials (160g), 2,000ml of distilled water and 10% (wt/wt) of catalyst to plant residue were fed into the reactor. It was observed that the maximum heavy oil yield was about 29% from the feeding stock, barley straw, with addition of KOH. The caloric values of crude oil from different crop residues were ranged from 55% to 66% relative to the raw materials depend on crop residue. It was appeared that its maximum calorific value from wheat straw was approximately 6190 kcal/kg.

• 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.

• Research in Plant Disease
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• v.7 no.2
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• pp.107-111
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• 2001

Deterioration of pod and seed quality by pod and stem blight and purple blotch is a serious problem in the production of vegetable soybean. Major inoculum sources for the causal pathogens, Phomopsis spp. and Cercospora kikuchii, are soybean straw and debris. Phomopsis spp. have been known to be either limited for hyphal growth or latent in immature soybean tissues. In this experiment, cultural practices using these ecological traits of the pathogens were applied as a control measure. In plastic mulching, seed infection was remark ably reduced by drip irrigation as compared to overhead sprinkling, but not reduced in no mulching cultivation. Control value of plastic mulching was 28.0% for pod and stem blight and 29.3% for purple blotch, which was lower than that of benomyl application. By the first week in June, 78% of overwintered soybean straw examined contained matured alpha spores in pycnidia, acting as primary inoculum. Secondary inoculum of phomopsix spp. was observed abundantly throughout from mid June to September on fallen cotyledons from current crops and subsequently was found on petiole debris. Consequently, both plastic mulching and drip irrigation were effective to some extent for controlling pod and stem blight and purple blotch without significant reduction in soybean yield, and the cultural practices in combination with field sanitation resulted in removing more the secondary inoculum.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.137-142
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• 1998

Assessment of N release pattern from hairy vetch (Vicia villosa Roth) residue is an important step for the efficient use of the residue as a green manure and the specific management strategy development. Objective of this research was to determine the changes of chemical composition, especially in light of the N release, when the residues of hairy vetch were applied in the soil. hairy vetch was harvested at different growth stages (April 23, May 9, and May 28) and the residues were encapsulated in the nylon mesh (1 mm) bag. The bags were placed on the surface of no-tillage plots and buried at 15cm in depth in conventional tillage plots of the corn field in early June. The bags were removed for measurements of dry matter and N content at 1, 2, 3. 5, 8 and 12 weeks after placement. Dry matter and N content of hairy vetch were higher when harvested closer to maturity, as also found in C/N ratio, cellulose and hemicellulose contents. The rate of N releases from hairy vetch residue under conventional tillage condition was greater than that under no-tillage condition. Percentages of N remaining in residue over the initial N contents under conventional tillage condition were in average 40, 23, and 15% for 1, 2, and 3 weeks after placement of mesh bag, respectively, compared with respective values of 71, 31, and 21% under no-tillage condition. The rate of N release was slower as the harvest time was closer to maturity of hairy vetch under both tillage conditions. Most of N in residue was released within 3 and 5 weeks, under conventional and no-tillage conditions, respectively. Results indicated that amounts of N released from hairy vetch residue were more closely related to the variability of N contents in residue due to the harvest time than changes of chemical composition of plant or soil management.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.266-287
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• 2004

The non infecting, plant associated bacteria have attracted increased attention for stimulating plant growth and as environmental friendly plant protecting agents. Pink-pigmented facultatively methylotrophic bacteria (PPFMs), classified as Methylobacterium spp., are persistent colonizers of plant leaf surfaces. As the leaves of most or all plants harbor PPFMs that utilize leaf methanol as their sole source of carbon and energy, which is a specific attribute of the genus Methylobacterium. Although they are not well known, these bacteria are co-evolved, interacting partners in plant metabolism. This claim is supported, for example, by the following observations: (1) PPFMs are seed-transmitted, (2) PPFMs are frequently found in putatively axenic cell cultures, (3) Low numbers of seed-borne PPFMs correlate with low germinability, (4) Plants with reduced numbers of PPFM show elevated shoot/root ratios, (5) Foliar application of PPFMs to soybean during pod fill enhances seed set and yield, (6) Liverwort tissue in culture requires PPFM-produced vitamin B12 for growth, (7) treated plants to suppress or decrease disease incidence of sheath blight caused by Rhizoctonia solani in rice, and (8) the PPFM inoculation induced number of stomata, chlorophyll concentration and malic acid content, they led to increased photosynthetic activity. Methylobacterium spp. are bacterial symbionts of plants, shown previously to participate in plant metabolism by consuming plant waste products and producing metabolites useful to the plant. There are reports that inform about the beneficial interactions between this group of bacteria and plants. Screening of such kind of bacteria having immense plant growth promoting activities like nitrogen fixation, phytohormone production, alleviating water stress to the plants can be successfully isolated and characterized and integration of such kind of organism in crop production will lead to increased productivity.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.104-109
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• 2010

Hydro-thermal liquefaction technology for rapeseed straws was investigated the biomass conversion rate with different catalysts and reaction temperatures. NaOH and KOH were used for catalysts, and the reaction temperature were ranged from 180 to $320^{\circ}C$ at every $20^{\circ}C$ of intervals for 10 minutes. The reaction was carried out in a 5,000 mL liquefaction system with dispenser and external electrical furnace. Raw materials (160g), 2,000 mL of distilled water and 10% (wt/wt) of catalyst to plant residue were fed into the reactor. It was observed that the maximum crude oil yield was about 36% at temperature range, $260{\sim}280^{\circ}C$ with KOH and at $300^{\circ}C$ with NaOH, respectively. It was observed that the more calorific values of crude oil, the higher reaction temperature with KOH, but it had the reverse pattern in NaOH.

• Korean journal of applied entomology
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• v.52 no.3
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• pp.239-241
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• 2013

First known female of the sac spider Clubiona zacharovi Mikhailov, 1991 is described from Korea. This is a rare species inhabiting in the plant litter or under the stone in mountain sites.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.111-120
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• 1993

We investigated in the existential forms of heavy metals and their distribution in plant and soil surrounding ruined mine in Daduk area. The content of heavy metals in soils was more plentiful in A soil than that in another soil, excepting only Mn. The content of Mn in soils was greater in B soil than those in another soils. The content of each heavy metals, according to existential form, had different patterns on the comparision of each elements ; organic-form on Cd and As, Carbonate-form Cu, Pb and Mn and Residual-form on Fe and Zn. The popularity ration of M. senensis and J. decipiens were about 65% and 72%, respectively, and which means that these plants had resistances to heavy metals. The contents of heavy metals absorbed in root was higher than those of stem except Mn, In M. sinensis, the contents of Zn in root was similar to that of stem. To study the heavy metal contents in water, the highest content of heavy metal, mainly Fe, Mn and Zn, were calculated in extracting water.