• Journal of Life Science
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• v.14 no.4
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• pp.560-566
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• 2004

Agrocybe aegerita is Hymenomycetes fungus belonging to the order Agaricales and family of Bolbitiaceae. Much less is known about liquid culture of Agrocybe aegerita. Thus, the present study was to investigate the liquid cultural characteristics of Agrocybe aegerita my-celium. The optimal medium for the mycelial growth and density was ME medium, optimal tem-perature and initial pH were 25$\pm$1$^{\circ}C$ and 5.5, respectively. And optimal culture time for mycelial growth was 12 days. The modified optimal medium compositions were dextrin 3% (w/v), yeast extract 2% (w/w), MgSO$_4$0.05% (w/v), and KH$_2$PO$_4$0.15% (w/v). Under optimal culture conditions, the mycelial growth of modified optimal medium was higher than that of ME medium.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.85-94
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• 2007

To determine the influence of food waste compost (FWC) application on paddy soil, FWC was applied to the paddy soil and then compared with farmer's practice as to the effects on rice and soil environment. Initially, pig manure compost (PMC) had high content of phosphorus ($15g\;kg^{-1}$) and potassium ($23g\;kg^{-1}$), while FWC had high content of total nitrogen ($13g\;kg^{-1}$) and salinity ($18.5g\;kg^{-1}$). Comparison was also made between chemical fertilizer and FWC use as a trial in the paddy field under the clay loam and sandy loam soil. In the panicle formation stage, chemical fertilizer application was proper in clay loam while PMC application was proper in sandy loam. However, chemical fertilizer produced higher yield compared to compost treatment, both on clay loam and sandy loam with 20~25% and 17~19%, respectively. The lower yield in sandy loam maybe due to slow mineralization of compost such that the crop did not effectively use it. Organic matter content in paddy soil after experiment was higher in FWC and PMC plots compared to that in chemical fertilizer plots. But the other soil properties were comparable. Therefore, the FWC compost had little effect on soil when it use as a trial in paddy field. Likewise, after the application of FWC as a trial, analysis of nitrate nitrogen and ammonium nitrogen in the surface water and 60 cm depth of paddy soil water nine days after planting was done. Results revealed that concentration of ammonium nitrogen was similar to irrigation water while nitrate nitrogen concentration was not detected, and hence did not contribute to water pollution. It is concluded that the application of FWC in the paddy field had not affected on environmental pollution in the paddy field. But its use as compost during rice culture reduced yield quantity. Such study should include selection of compost material, amount and method of compost application.

• Korean Journal of Environmental Agriculture
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• v.18 no.4
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• pp.372-377
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• 1999

Objective of this research was to draw the basic criteria of the compost maturity evaluation, by assessing the stability of chemical and physical properties of the bark and piggery manure byproduct composts during the composting. Colors of the mature composts were black and dark brown for the bark and piggery manure by-product composts, respectively. Good earthy odor was detected for both by-product composts after approximately 40 days composting, by which odors of the original raw materials were disappeared. pH and EC of the mature bark: compost were stabilized at 6.5 and 1dS/m, respectively. The respective values for the piggery compost were stabilized at 7.2 and 6dS/m. Organic matter contents were decreased with time to be stabilized at about 60% at the end of composting. During composting, total N contents of the bark and piggery composts were maintained at $1.1{\sim}1.5%$, and $1.5{\sim}2.2%$, respectively. For both fertilizers, $NH_4-N$ contents were increased at the initial stage bur. decreased after the middle stages of decomposition, resulting in the increase of $NO_3-N$ contents. Total inorganic N contents were increased with time. C/N ratios of both mature composts were stabilized at $25{\sim}27$. CEC of the bark compost was increased logarithmically with time and that of mature compost was 87cmol(+)/㎏. CEC of the piggery manure compost was hyperbolic function with rime and reached at 70cmol(+)/㎏ at the mature stage. Crude fiber analysis indicated that relative contents of lignin were increased with composting by compensating for the decreases of cellulose and hemicellulose contents.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.479-486
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• 2008

The cultural characteristics and antibacterial activities of Cordyceps militaris and Paecilomyces tenuipes were compared. The mycelial growth was the highest on MCM (Mushroom Complete Medium) for C. militaris and on YMA (Yeast Malt Agar) for P. tenuipes. But the mycelial density on MMM (Mushroom Minimal Medium) was lower than other on media. The optimum mycelial growth was observed at $25^{\circ}C$. C. militaris was low mycelial growth when it was transferred over 5 times generation. The carbon source for the optimum mycelial growth was fructose of monosaccharide, maltose of disaccharide and dextrin of polysaccharide. The calcium nitrate of organonitrogen was found the best mycelial growth on C. militaris, while the sodium nitrate observed to be well for mycelial growth on P. tenuipes. The ammonium tartrate was observed to be the best among the inorganonitrogen used for mycelial growth. Antibacterial activities were found out just C. militaris against Bacillus cereus of Gram (+).

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.29-34
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• 1997

This experiment was carried out to investigate the effects of nitrate concentration in culture solution on the growth and the uptake of inorganic elements in Tomato plant in the greenhouse. Tomato plants(cv. TVR-2) were grown with nitrate concentrations 8, 16, 24, 32cmol/l, based on Japan ENSI standard solution. Dry weights of lamina and petiole increased with the nitrate concentration. However, the dry weight of fruit was the highest in the treatment of nitrate concentration of 16cmol/l. The proportion of dry weights of vegitative organ to reproductive organ was the lowest in the treatments of nitrate concentrations of 16cmol/l and it increased with the nitrate concentration. The fruit yield was the highest at the treatment of nitrate concentration of 16cmol/l. With the increase of nitrate level the concentrations of N, $NO_3-N$, Ca and Na increased in lamina and petioles. The concentrations of K, P, S and Cl tended to decline in the nitrate concentration of 16 and 32cmol/l. These results indicate that optimum nitrate concentrations in a tomato grown by hydroponics change with growth stage, and the optimum concentrations for vegitative and reproductive stage were 8 and 16cmol/l, respectively. It also was proved that the nitrate concentrations in the culture solution affected antagonistically the uptake of inorganic anion in tomato : In low nitrate level $Cl^-$ uptake was affected much, while $SO_4{^{2-}}$ and $H_2PO_4{^-}$ uptake were affected in high nitrate level.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.408-419
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• 2006

A pot experiment was conducted for two years to evaluate the effects of purified Si fertilization combined with $^{15}N$ on the nutrient uptake, plant growth characteristics, and photosynthetic characteristics of rice in water melon cultivated soil. In 2002, plant height was positively affected at 25 DAT (Day After Transplanting) by Si fertilization in 100%N treatment. However, in 2003, plant height at 25 DAT was negatively affected by Si fertilization in low N level but it was reversed in high N level with initial increase of plant height. Tiller number per pot was positively affected by N and Si fertilization level, especially for high N fertilized treatment. Leaf color was positively affected by Si fertilizatlon in no N fertilized pots, however, Si was not effected in 50%N and 100%N fertilized treatments. N harvest index (NHI) increased with increased Si fertilization in no N plots, however it decreased with increasing of N fertilization level. Nitrogen use efficiency (NUE) decreased with increasing of fertilized N but Si fertilization increased NUE in 50%N plots, however, it was not different by the Si fertilization level in 100%N plots. In 50%N+200%Si plots, NUE was greatest with 130 and shoot N content was $16.2g-N/m^{2}$. N content ($g/m^{2}$) in rice plant increased with increasing Si fertilization in no N plots at panicle initiation stage, 50 and 100%N plots at heading stage and all N treatment at harvesting time. This was mostly more efficient in late growth stage than early growth stage. The concentration (%) of P and K increased with increasing N fertilization level at heading and harvesting but it was not significantly different by the Si fertilization treatment except a little decreasing with increasing Si fertilization level at heading. Potassium content was also not significantly related with N fertilization level except increasing with Si fertilization level at panicle initiation stage. Plant Ca content (%) decreased with increasing of Si fertilization at heading stage and Si fertilization increased Ca content at panicle initiation stage and heading stage and it increased with increasing of Si fertilization level. Photosynthetic activity was not directly related with Si fertilization amount, however, Fluorescent factors, Fv'/Fm' and PsII, were positively affected by Si fertilization level. In conclusion, N fertilization in Si 200% fertilized condition should be reduced by about 50% level of recommended N fertilization for rice cropping in green-house water-melon cultivated paddy field. However, improvement of Ps by Si fertilization could not be attributed to Ps activity in the same leaf area but because of increased total leaf area per pot improved fluorescent characteristics.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.185-190
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• 2008

In order to obtain the basic information for agricultural utilization of Germanium(Ge), the growth characteristics and the germanium uptake by water celery were investigated at different concentration of germanium in soil. This experiment was carried out in the Wagner pot(1 $5,000^{-1}a$). Germanium concentrations in soil for water celery cultivation were maintained at 0.26, 25.0, 62.5, and 125.0 mg $kg^{-1}$, respectively. The treatment of over Ge 25.0 mg $kg^{-1}$ in the soil led to germanium phytotoxicity such as reduction of plant height and fresh weight. The contents of germanium in water celery were increased with the increase of germanium concentration in the soil. When water celery was cultivated from soil maintained with Ge 25.0 and 62.5 mg $kg^{-1}$, its germanium contents in plant were 89.9 and 371.6 mg $kg^{-1}$, respectively. Then, the efficiency of germanium uptake of water celery in Ge 25.0 and 62.5 mg $kg^{-1}$ maintained plots was 1.7 and 2.4%, respectively. When water celery was cultivated from soil maintained with Ge 25.0, 62.5 and 125.0 mg $kg^{-1}$, its content of amino acid was found to be 89.8, 198.4, and 318.2 mg $g^{-1}$, respectively. To investigate the effect of N fertilizer application in uptake of germanium by water celery, these were treated with nontreatment, 1.0, 1.5 and 2.0 times of N application based on soil testing for cultivation of water celery. However, the amount of the N fertilizer application did not affect the contents of germanium in the water celery. When water celery was cultivated from soil maintained with two kinds of inorganic and organic germanium 50 mg $kg^{-1}$, respectively, the content of germanium were 24.2 mg $kg^{-1}$ in the Ge-132 treatment and 11.8 mg $kg^{-1}$ in the $GeO_2$ treatment.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.729-734
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• 2012

During chlorination processes dissolved organic nitrogen (DON) can form toxic nitrogenous disinfection byproducts and organic chloramines which have little or no bactericidal activity. DON needs to be removed before chlorination processes to reduce the formation of those products. This study investigated the removal of DON from surface water and reclaimed water by coagulation with aluminum sulfate (alum) and a cationic polymer (polyDADMAC). Removal characteristics of dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm ($UVA_{254}$) were compared with that of DON. Coagulation with alum removed DON, DOC, and $UVA_{254}$ with similar trends, but the removal of $UVA_{254}$ was highest. A dual coagulation strategy of alum and cationic polymer improved the removal of DON. Coagulation with cationic polymer alone was not effective due to its narrow range of charge neutralization. DON in reclaimed water was easier to remove than that in surface water, and higher molecular weight fraction (>10,000 Da) of DON was preferentially removed.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.731-743
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• 2018

This study was conducted to evaluate the effects of green manures and complemental fertilization with oil cake or liquid fertilizer on growth and nitrogen use efficiency of Chinese cabbage cultivated in organi systems. Field experiments were carried out at the National Institute of Agricultural Science in Suwon, South Korea from 2012 to 2014. Two green manure crops, Crotalaria and Hairy vetch, was cultivated in summer and in winter, respectively. The application methods of the green manure consisted of three tillage systems (overall tillage, partial tillage and no tillage). Oil cake and liquid fertilizer were used as complemental fertilizer. The results showed that when used as covering material in the upland soil without tillage, green manure fertilization was more effective in increasing growth and yield of Chinese cabbage than when incorporated into soil. It was possible to grow and harvest Chinese cabbage in the spring season by the application of hairy vetch as winter green manure. The higher yield of Chinese cabbage with green manure application was caused by the lower incidence rate of soft rot and tip-burn. The yield of the Chines cabbage that received green manure applications over two consecutive seasons followed by the supplemental fertilization with oil cake was similar to that of the conventional chemical fertilization. Following a single season green manure application in summer, however, the yield of cabbage was only about 70% of the conventional treatment. Green manure cultivation with additional liquid fertilization produced a yield similar to the conventional fertilization treatment, soil inorganic nitrogen concentration remained stable and the nitrogen use efficiency increased in the green manure applied soil. In conclusion, the organic cultivation of Chinese cabbage in the autumn season could be outperformed in the upland soil receiving two seasons (winter and summer) of green manure fertilization followed by the supplemental fertilization with liquid fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.165-170
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• 1991

Effects of liming and starch application on the soil pH and mineralization of organic nitrogen were compared to control at $30+/10^{\circ}C$ incubation for six weeks in two soil types(loam, sandy loam) adjusted with 80% of field moisture capacity. 1. While soil pH was increased abruptyl one week after incubation in loam applied with lime and lime+starch, it tended to decrease at control during incubation period. Liming on sandy loam increased soil pH, and application of lime+starch together showed high pH at first week of incubation which was lowered slowly after wards. Significant changes in soil pH was not detected at control or starch application only. 2. The content of $NH_3-N$ in loam started to increse three weeks after incubation, and was maximized at fifth week. Positive correlation was shown at control during incubation period between soil pH and $NO_3-N$ content. Level of $NO_3-N$ content applied with starch or lime+starch was low compared to control. 3. The $NH_4-N$ content was high when sandy loam was applied with lime+starch together. At the first week of incubation, the $NO_3-N$ content was high at control or lime application.