• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.807-817
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• 2008

Steers with ad libitum access to rice straw were assigned to four diets to evaluate the effects of maize or soybean hull supplementation on intake, in vivo digestibility, ruminal pH, VFA, ammonia-nitrogen ($NH_3-N$) and in situ ruminal disappearance of feed nutrients by cattle consuming rice straw. Supplement treatments were: no supplement (RS); soybean meal at 0.127% BW (SBM); cracked maize at 0.415% BW plus 0.044% BW soybean meal (MAIZE); or soybean hulls at 0.415% BW plus 0.044% BW soybean meal (HULLS). The MAIZE and HULLS diets were formulated to provide approximately 4 MJ of $NE_m$ per kg of diet. Rice straw DMI was not affected (p = 0.34) by supplement. Apparent dry matter (DM) digestibility was greater (p<0.001) for MAIZE and HULLS (56.6 and 60.0%, respectively) than for steers consuming SBM or RS (51.8 and 44.4%, respectively). Apparent NDF digestibility was greater (p<0.0004) for HULLS than MAIZE (61.7 vs. 58.0%, respectively) and apparent ADF digestibility was greater (p<0.0008) for HULLS than MAIZE (61.1 vs. 49.2%, respectively). There was no difference in apparent hemicellulose digestibility (p = 0.43). Analysis of ruminal fluid collected 0, 2, 4, 6, and 8 h post-feeding revealed ammonia-nitrogen was greatest (p<0.05) for steers on SBM and HULLS diets at 2 h (24.08 and 22.57 mg/dl, respectively) and total volatile fatty acids was greatest (p<0.05) for HULLS at 4 h (230 mM/L). In situ disappearance, measured at 0, 2, 4, 6, 8, 16 and 24 h, indicated that SBM, MAIZE and HULLS tended to enhance the digestibility of DM and fiber components of rice straw. In situ disappearance of rice straw DM was greatest for SBM and/or HULLS from 4 to 24 h (p = 0.03). Rice straw NDF and ADF disappearance was enhanced by supplementation from 16 to 24 h (p<0.02). Rice straw DM, NDF and ADF disappearances at 24 h were similar for MAIZE and HULLS treatments. When feeding cattle rice straw diets, energy and protein-based supplements are essential. This study showed that fiber-based supplements are just as, if not more, effective as starch-based supplements in rice straw utilization. This study shows that soybean hulls, in spite of their high fiber content, are as efficient as maize for supplementing rice straw primarily because fiber in soybean hulls is highly digestible as shown by in vivo digestibility and in situ disappearance.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.4
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• pp.519-534
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• 2019

When the fresh water from the artificial lakes (Ganwolho and Bunamho) were discharged to Cheonsu Bay in summer to prevent the flood over the reclaimed farmland near the lakes, the impact on water qualities (nutrients, organic matters, trace metals) within the bay was investigated through four surveys (June, July, August and October, 2011). Dissolved inorganic nitrogen (DIN) increased about as much as 3-4 times over the whole water column when the freshwater was discharged. And the main species composition of DIN changed from ammonia to nitrate. Dissolved inorganic phosphorus (DIP) decreased as much as 2 times in surface waters, but increased as much as 1.5 times in deep waters, and also silicate concentrations increased as much as 3-4 times in deep waters of the inner bay. The N/P ratios in Chunsu bay seawaters were much higher (2 to 7 times) than the Redfield ratio when the freshwaters were discharged, which indicated the phosphorus limiting in the phytoplankton growth. Dissolved organic carbon (DOC) and nitrogen (DON) increased as much as about 2 times. In addition, particulate organic matters (POC, PON, POP, Bio-Si) increased as much as above 2 times in the surface waters of the inner bay. Trace metals (Fe, Mn, Co, Ni, Cu) increased in the surface waters of the inner bay, but dissolved Cd concentrations decreased as much as 2 times. Therefore, when the contaminated fresh waters from the artificial lakes were discharged into the bay, nutrients, organic matters and trace metals generally increased compared to normal period. Since the phytoplankton bloom occurred in the surface waters of the inner bay, dissolved oxygens at the surface waters were oversaturated and hence hypoxic in the deep waters. Highly enriched nutrients concentrations were found in deep waters of the inner bay, which was accompanied with the hypoxic condition. Finally, the water quality in the inner bay of the Chunsu bay was deteriorated from less than grade 3 in normal periods to grade 5 when the freshwaters from the artificial lakes were discharged in summer.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.509-520
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• 1997

This is a report on the early vegetation, plant community structure, and secondary succession of cut and uncut sites of burned areas in Mt. Gumo-sun. The forest fire occurred on April, 1994 and the pine forest and its floor vegetation were burned down. The investigation was carried out from April, 1995 to October, 1996. The results are summarized as follows : The floristic composition of cut and uncut sites of burned area and unburned area were composed of 32, 36, and 34 kinds of vascular plants respectively. The biological spectra showed the $H(G)-D_1-R_5-e$ type, $H(M)-D_1-R_5-e$ and $M(N)-D_1-R_5-e$ in cut, uncut, and unburned site respectively. The dominant species based on $SDR_3$ of the cut site were Miscanthus sinensis var. purpurascens(100.00). Caret humilis(52.27), Quercus serrata(51.19) and Lysimachia clethroides(39.40), however, in the uncut sites the dominant species were Quercus acutissima(56.91), Pinus densiflora(26.83) in the tree layer, Quercus serrata(50.43), Lindera glauca(40.51), Lespedeza bicolor(37.85) in the shrub layer, and Miscanthus sinensis var. purpurascens(72.27), Pteridium aquilium var. latiusculum(60.92), Carex humilis(63.63) in the herb layer. Pinus densiflora(99.88), Miscanthus sinensis var. purpurascens(82.74), Quercus serrata(77.47) and Carex humilis(74.02) were dominant in the unburned site. The species diversity(H) and evenness index(e) were 1.05, 0.70 and 1.32, 0.85 in the cut and uncut site, respectively and 0.22, 0.63 in the unburned site. Dominance index(C) was 0.15, 0.06 and 0.96 in the cut, uncut site and unburned site, respectively. Degree of succession(DS) was 345.19, 747.47 and 674.34 in cut, uncut and unburned site, respectively. The index of similarity(CCs) was 0.66 between cut and uncut sites, 0.50 between unburned and cut sites and 0.61 between unburned and uncut sites. The amount of exchangeable sodium, calcium, magnesium and soil pH were increased, but the amount of organic matter, available phosphous, total nitrogen, total carbon and exchangeable potassium were decreased in cut site after fire.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.106-113
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• 2005

This study was carried out to develop a novel hydroponic medium far fruit vegetable crops by using waste synthetic fibers. In physical analysis of the synthetic fiber medium (SFM), the bulk density and percent solid phase were lower, while the porosity and water content were greater in comparison with the rockwool slab. The SFM had pH of 6.5 and EC of $0.03dS{\cdot}m^{-1}$ both of which are similar to those of the rockwool slab. The CEC of 0.39me/100mL of the SFM was lower than compared with 3.29me/100mL of the rockwool slab. However, concentrations K, Ca, Mg and Na were slightly higher in the SFM than those in the rockwool slab. The 'Momotaro' tomato crop in the SFM gave comparable plant height, stem diameter, days to first flowering, fruit weight and percent marketable yield as the rockwool slab. In the SFM and in the rockwool slab, mean fiuit weight were 182g and 181g, percent marketable yield were $93.8\%$ and $92.0\%$, respectively. The marketable yield per 10a in the SFM was 12,799 kg, which was $97\%$ of that in the rockwool slab. Growth parameters such as leaf length and width, leaf number, stem diameter and chlorophyll content of an exportable cucumber crop grown in the SFM and the rockwool slab were not different. Fruit weight was greater in the rockwool slab, while percent marketable yield was greater in the SFM. The marketable fruit yield per 10a of 5,062kg in the SFM was $2\%$ greater than that in the rockwool slab. $NO_3$ concentration in nutrient solution during the crop cultivation was higher in the SFM than in the rockwool slab, while concentrations $NH_4$, K, Ca, Mg and $SO_4$ were not different between the two media.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.354-374
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• 2016

This study explored spatiotemporal variability of water quality in correspondence with hydrometeorological factors in the five stations of Paldang Reservoir located in the Han River during 4 years from May 2012 to December 2015. Variability of basic water quality factors were largely related with seasonal fluctuations of hydrology. Temperature stratification occurred in the deep dam station, and prolonged hypoxia was observed during the draught year. Nitrogen nutrients were increased with decreasing inflow in which changing pattern of $NH_4$ reversed to $NO_3$ by the effect of treated wastewater effluent. Phosphorus increase was manifest during the period of high inflow or severe drought. Chl-a variation was reversely related with both flow change and AGP(algal growth potential) variations. Our study demonstrated that water quality variability in Paldang Reservoir was largely attributed to both natural and operational changes of inflow and outflow (including water intake) based on major pollution source of the treated wastewater (total amount of $472{\times}10^3m^3d^{-1}$) entering to the water system from watershed. In the process of water quality variability, meteorological (e.g., flood, typhoon, abnormal rainfall, scorching heat of summer) and hydrological factors (inflow and discharge) were likely to work dynamically with nutrients pulse, dilution, absorption, concentration and sedimentation. We underline comprehensive limnological study related to hydro-meteorolology to understand short- and long-term water quality variability in river-type large reservoir and suggest the necessity of P-free wastewater treatment for the effective measure of reducing pollution level of Paldang drinking water resource.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.72-77
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• 1985

This study was performed to obtain some basic informations about the effects of irrigation water on the growth of rice plant. The water quality was surveyed at six pumping stations from the Nam river tributary to the downstream of Nakdong river, and sampling sites of soil and plant were five paddy fields near-by each station during rice growing periods in 1983. 1. Average value of COD was 5.1-7.1 ppm at 2 sites of the Nam river tributary, 11.4 ppm at 1 site of the midstream and 9.1-13.4 ppm at 3 sites of the downstream of Nakdong river. 2. The relationships between irrigation water and soil were $r=0.98^{**}$ for EC and $r=0.91^*$ for SAR, but the rest components did not. 3. Root activity of rice plant was low tendency as go by go the downstream of Nakdong river, and it was related to dry matter of rice plant ($r=0.62^{**}$), SAR ($r=-0.67^{**}$), and EC ($r=-0.62^{**}$) of soils.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1319-1326
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• 2014

Rapamycin, produced by the soil bacterium Streptomyces hygroscopicus, has the ability to suppress the immune system and is used as an antifungal, anti-inflammatory, antitumor, and immunosuppressive agent. In an attempt to increase the productivity of rapamycin, mutagenesis of wild-type Streptomyces hygroscopicus was performed using ultraviolet radiation, and the medium composition was optimized using glycerol (which is one of the cheapest starting substrates) by applying Plackett-Burman design and response surface methodology. Plackett-Burman design was used to analyze 14 medium constituents: M100 (maltodextrin), glycerol, soybean meal, soytone, yeast extract, $(NH_4)_2SO_4$, $\small{L}$-lysine, $KH_2PO_4$, $K_2HPO_4$, NaCl, $FeSO_4{cdot}7H_2O$, $CaCO_3$, 2-(N-morpholino) ethanesulfonic acid, and the initial pH level. Glycerol, soytone, yeast extract, and $CaCO_3$ were analyzed to evaluate their effect on rapamycin production. The individual and interaction effects of the four selected variables were determined by Box-Behnken design, suggesting $CaCO_3$, soytone, and yeast extract have negative effects, but glycerol was a positive factor to determine rapamycin productivity. Medium optimization using statistical design resulted in a 45% ($220.7{\pm}5.7mg/l$) increase in rapamycin production for the Streptomyces hygroscopicus mutant, compared with the unoptimized production medium ($151.9{\pm}22.6mg/l$), and nearly 588% compared with wild-type Streptomyces hygroscopicus ($37.5{\pm}2.8mg/l$). The change in pH showed that $CaCO_3$ is a critical and negative factor for rapamycin production.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.72-78
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• 1984

The water quality and the budget of pollutant loading in the downstream of Nakdong River were surveyed at 3 sites along the main stream from Mulgum to Hadan and 1 site of Yangsan tributary with response to the tides in May and June, 1983. The level of TSS in the Yangsan tributary, 6.1~21.3mg/l, was higher than any other site. The mean values of BOD were 1.16mg/l at Mulgum site, 1.83mg/l Yangsan site, 0.79mg/l Hwamyeong site and 3.56mg/l at Hadan site. The levels of NH sub(4) super(+)-N and PO sub(4) super(3-)-P were the highest at Hadan site, and the levels of zinc and copper were 2.11~5.98ppb and ND-50.00ppb at Yangsan tributary site. Although the flow rate of Yangsan stream accounted for only 4% of that of main stream, but the mean value of pollutant loading in the Yangsan stream amounted to 8.3% of the that of main steam.

• Korean Journal of Ecology and Environment
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• v.37 no.2 s.107
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• pp.180-192
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• 2004

This study was carried out to assess the seasonal variation of water quality and the effect of pollutant loading from watershed in a shallow eutrophic reservoir (Shingu reservoir) from November 2002 to February 2004, Stable thermocline which was greater than $1^{\circ}C$ per meter of the water depth formed in May, and low DO concentration (< 2 mg $O_2\;L^{-1}$) was observed in the hypolimnion from May to September, 2003. The ratio of euphotic depth to mixing depth ($Z_{eu}/Z_{m}$) ranged 0.2 ${\sim}$ 1.1, and the depth of the mixed layer exceeded that of the photic layer during study period, except for May when $Z_{eu}$ and $Z_{m}$ were 4 and 4.3 m, respectively. Most of total nitrogen, ranged 1.1 ${\sim}$ 4.5 ${\mu}g\;N\;L^{-1}$, accounted for inorganic nitrogen (Avg, 58.7%), and sharp increase of $NH_3$-N Hand $NO_3$-N was evident during the spring season. TP concentration in the water column ranged 43.9 ${\sim}$ 126.5 ${\mu}g\;P\;L^{-1}$, and the most of TP in the water column accounted for POP (Avg. 80%). During the study period, DIP concentration in the water column was &;lt 10 ${\mu}g\;P\;L^{-1}$ except for July and August when DIP concentration in the hypolimnion was 22.3 and 56.7 ${\mu}g\;P\;L^{-1}$, respectively. Increase of Chl. a concentration observed in July (99 ${\mu}g\;L^{-1}$) and November 2003 (109 ${\mu}g\;L^{-1}$) when P loading through two inflows was high, and showed close relationship with TP concentration (r = 0.55, P< 0.008, n = 22). Mean Chl. a concentration ranged from 13.5 to 84.5 mg $L^{-1}$ in the water column, and the lowest and highest concentration was observed in February 2004 (13.5 ${\pm}$ 1.0 ${\mu}g\;L^{-1}$) and November 2003 (84.5 ${\pm}$29.0 ${\mu}g\;L^{-1}$), respectively. TP concentration in inflow water increased with discharge (r = 0.69, P< 0.001), 40.5% of annual total P loading introduced in 25 July when there was heavy rainfall. Annual total P loading from watershed was 159.0 kg P $yr^{-1}$, and that of DIP loading was 126.3 kg P $yr^{-1}$ (77.7% of TP loading. The loading of TN (5.0ton yr-1) was 30 times higher than that of TP loading (159.0 kg P yr-1), and the 78% of TN was in the form of non-organic nitrogen, 3.9 ton $yr^{-1}$ in mass. P loading in Shingu reservoir was 1.6 g ${\cdot}$ $m^{-2}$ ${\cdot}$ $yr^{-1}$, which passed the excessive critical loading of Vollenweider-OECD critical loading model. The results of this study indicated that P loading from watershed was the major factor to cause eutrophication and temporal variation of water quality in Shingu reservoir Decrease by 71% in TP loading (159 kg $yr^{-1}$) is necessary for the improvement of mesotrophic level. The management of sediment where tine anaerobic condition was evident in summer, thus, the possibility of P release that can be utilized by existing algae, may also be considered.

• 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.