• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.353-360
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• 2011

In order to develop the application method of pig compost (PC) and liquid manure (LM) for whole crop barley cultivation, experiments were conducted at Munpo series (coarse loamy, mixed, nonacid, mesic family of Typic Fluvaquents) soil in Gyehwa-reclaimed land, six plots, a LM applied rate as N% ; non-application, chemical fertilizer (CF)100, 100, 50+50, 50+CF50 and (PC30+LM40)+LM50 as basal and additional fertilizer. $NO_3^-$-N content in soil was decreased as along with the growth of plant, highest in LM100% as basal fertilization at early growth stage and highest in (PC30%+LM40%)+LM40% and CF100% at last growth stage. Amount of $NO_3^-$-N and $NH_4^+$-N in soil was high in (PC30%+LM40%)+LM40% and CF100% of top soil but in subsoil significant difference was little in all treatment. Amount of OM, $A_V.P_2O_5$, T-N, exchangeable Ca and Na in soil was higher (PC30%+LM40%)+LM40% than non-application after harvest. Amount of nutrient uptake in plant was higher in CF100% and split application of LM than LM 100% application. Nitrogen utilization rate was in the order of CF100% >LM50%+LM50%=LM50%+CF50%>(PC30%+LM40%)+LM40% >LM100%. The yield of whole crop barley in (PC30%+LM40%)+LM40% and CF100% was 3.2 times more than in non-application ($309kg\;10a^{-1}$). Feed values such as crude protein and TDN was increased 1.0% ~ 1.4% in LM as split application than basal 100% treatment. Accordingly, in order to increase yield of a whole crop barley with application PC+LM in reclaimed land treat split application rather than to treat LM 100% into the land.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.1-9
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• 2021

This study was conducted to examine the changes of photosynthesis, growth, chlorophyll contents and functional material contents in light intensity and EC concentration of wild baby leaf vegetable, Indian lettuce (Lactuca indica L. cv. 'Sunhyang') in DFT hydroponics. The cultivation environment was 25±1℃ of temperature and 60±5% of relative humidity in growth system. At 14 days after sowing, combination effect of light intensity (Photosynthetic Photon Flux Density (PPFD 100, 250, 500 µmol·m-2·s-1) and EC level (EC 0.8, 1.4, 2.0 dS·m-1) of nutrient solution was determined at the baby leaf stage. The photosynthesis rate, stomatal conductance, transpiration rate and water use efficiency of Indian lettuce increased as the light intensity increased. The photosynthesis rate and water use efficiency were highest in PPFD 500-EC 1.4 and PPFD 500-EC 2.0 treatment. The chlorophyll content decreased as the light intensity increased, but chlorophyll a/b ratio increased. Leaf water content and specific leaf area decreased as light intensity increased and a negative correlation (p < 0.001) was recognized. Plant height was the longest in PPFD 100-EC 0.8 and leaf number, fresh weight and dry weight were the highest in PPFD 500-EC 2.0. Anthocyanin and total phenolic compounds were the highest in PPFD 500-EC 1.4 and 2.0 treatment, and antioxidant scavenging ability (DPPH) was high in PPFD 250 and 500 treatments. Considering the growth and functional material contents, the proper light intensity and EC level for hydroponic cultivation of Indian lettuce is PPFD 500-EC 2.0, and PPFD 100 and 250, which are low light conditions, EC 0.8 is suitable for growth.

• Journal of Mushroom
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• v.18 no.4
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• pp.344-356
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• 2020

This study aimed to investigate the biological activities and amino acid content in the mixtures of roasted edible mushrooms (Pleurotus ostreatus, and Lentinula edodes) and grain additives (oat and brown rice) obtained under different extraction conditions for the development of mushroom tea. The total amount of polyphenol and β-glucan in edible mushrooms was increased with the roasting treatment compared to that observed with the air-drying treatment. In addition, DPPH radical scavenging activity and the amount of all amino acid components, including glutamic acid (Glu), were higher in the oat extracts than those observed in the brown rice. The biological activities and nutrient content were examined based on extraction temperatures and thetime required to obtain the mixtures of edible mushrooms and grain additives. The extract of a 1:1 mixture of L. edodes + oat (LE+O) obtained at 100℃, 3 min showed high DPPH radical scavenging activity (33.5%), and the extract of 3:1 mixture of P. ostreatus + brown rice (PO+B) obtained at 100℃, 3 min showed high nitrite scavenging activity (49.9%). The total polyphenol content of the extract of 3:1 mixture of P. ostreatus + brown rice (PO+B) was the highest when obtained at 16.2 mg GAE/g and+ brown rice (PO+B) was the highest when obtained at 16.2 mg GAE/g and 70℃, 10 min. The essential amino acid content was higher in the 1:1 mixing ratio of P. ostreatus + oat (PO+O) and P. ostreatus + brown rice (PO+B) and 3:1 mixing ratio. L. edodes + oat (LE+O) and L. edodes + brown rice (LE+B) compared to that observed in other mixing ratios.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.55-64
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• 2023

This batch experiment was conducted to investigate the patterns of major plant nutrients in the leachates from the soil that was incorporated with rice hull biochar adjusted pH with dry fish powder utilizing rice hull biochar for loading the soil microorganisms. The rice hull biochar adjusted pH between 6.0 and 7.0, and the mixture ratio of rice hull biochar and dry fish powder was 4:6. The treatments consisted of three; the soil incorporated with rice hull biochar non-adjusted pH with dry fish powder as control (RB + DF), the soil incorporated with rice hull biochar adjusted pH by pyroligneous acid solution and dry fish powder (RBP+DF), and the soil incorporated with rice hull biochar adjusted pH by citric acid solution and dry fish powder (RBC+DF). NH₄-N, NO₃-N, PO₄-P, and K concentrations in the leachates were analyzed during incubation. The accumulated NH₄-N and PO₄-P concentrations in the leachates from the RBC+DF treatment were the highest during leaching periods. The highest accumulated NO₃-N and K concentrations in the leachates from the RBP+DF treatment were observed. It observed that NH₄-N and PO₄-P were more released in the adjusted citric acid solution, but NO₃-N and K were less released than those in the pyroligneous acid solution due to their low absorption capacity. Furthermore, it is necessary to investigate crop growth responses to the soil incorporated with adjusted pH rice hull biochar and dry fish powder for loading soil microorganisms.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.195-204
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• 2002

Two experiments were conducted to study the effects of nutrient level and feeding method of split diets for a.m. and p.m. on laying hen performance, feed cost and eggshell quality. In experiment 1, 384 ISA Brown layers of 30∼38wk of age were assigned to four treatments which comprise of three replicates each containing 32 birds. The control(C) was fed a conventional single diet throughout the day and split diet groups(T1, T2 and T3) were offered high energy/protein-low Ca diets, and low energy/protein-high Ca diets in a.m.(04:00∼15:00) and p.m.(15:00∼21:00), respectively. In the split diet groups, daily ME and CP consumption, and feed cost were significantly reduced(P<0.05) compared to the C, while the hen-day egg production, average egg weight and daily feed intake were not different among treatments. Due to the reduced daily ME and CP intakes and feed cost, the conversions of feed, ME, CP and feed cost required per day and per kg egg mass were also significantly improved(P<0.05) in the split diet groups. Eggshell qualities (egg specific gravity, egg breaking strength and eggshell thickness) were improved(P<0.05) by split diet feeding. As the Ca level of the p.m. diet increased. In Experiment 2, 384 ISA Brown layers of 50∼58 wk of age were used in three treatments and each treatment was represented by four replicates each containing 32 birds. The control(C) was fed a conventional single diet throughout the day and split diet group(T1) was offered high energy/protein-low Ca diets, and low energy/protein-high Ca diets in a.m.(04:00∼l5:00) and p.m.(15:00∼21:00), respectively. T2 group was fed the diet mixed (50:50) with the a.m. diets in mash and p.m. diet in pellet used T1 group. In T1 and T2 groups, daily feed intake and average egg weight were significantly reduced(P<0.05) compared to the C, while the hen-day egg production was not influenced by the feeding system. Daily ME and CP consumption, and feed cost were reduced(p.0.05), and the conversions of ME, CP and feed cost required per egg were also significantly improved(P<0.05) in T1 and T2, while the conversions of feed, ME, CP and feed cost required per kg egg mass were not different to the C. Eggshell qualities of T1 and T2 were improved(P<0.05) compared to the others. It was concluded the feed and nutrients consumption, feed cost per day or per kg egg mass could be reduced by introducing split diets for a.m. and p.m. and the feeding method of mixed diet of split diets were also convenient and effective for sparing feed cost and improvement of eggshell quality.

• Journal of Nutrition and Health
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• v.9 no.2
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• pp.59-67
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• 1976

A series of experiment was carried out to study the effect of commonly used dietary fat or oils on the growth, feed efficiency, nutrient utilizability, nitrogen retention and serum cholesterol of rats and chicks fed various fat or oils at the level of 10% during 12 weeks of experimentation. Fat and oils used in this experiment were also analyzed for the composition of some fatty acids. The main observations made are as follows: 1. All groups received fat or oils gained more body weight than unsupplemented control group except chicks fed fish oil and rapeseed oil although no statistical significance was found between treatments. It was found that body weight gain achieved by the rats fed soybean oil, rapeseed oil, animal fat or corn oil was much greater than other group and that achieved by the chicks fed corn oil and animal fat was greater than other vegetable oil groups, although no statistical significance was found among treatments. 2. Feed intake data indicated that corn oil group of both rats and chicks consumed considerably more feed than other groups. Whereas feed intake of fish oil groups was the lowest among the experimental animals indicating that fish oil might contain unfavorable compound that depresses the palatability. In feed efficiency, soybean oil group of rats and corn oil group of chicks were significantly better than other experimental groups. In general, addition of fat or oils in the diet improved feed effeciency of diet. 3. Nutrient utiIizabiIity and nitrogen retention data showed that fat in the experimental diet containing 10% fat or oils was absorbed better than crude fat in control diet. It was also found that there was no significant difference in nitrogen retention among treatment. 4. Liver fat content of rapeseed oil group was much higher than that of control group and other group. It was also noticed that feeding more polyunsaturated fatty acids resulted in higher content of Iiver fat. 5. Present data indicated that serum cholesterol content of rapeseed oil and sesame oil group of rat was the higher than that of control group. Serum cholesterol content of animal fat group of chicks was higher than other group. It was interesting to note that serum cholesterol content of chicken was higher than that of rats?regardless of the kind of oils received. 6. Analytical data revealed that fatty acid composition of vegetable oil was composed mainly of oleic acid and linoleic acid, whereas animal fat and fish oil were composed of saturated fatty acid such as, myristic and palmitic acid. It should be mentionted that the perilla oil contained a very large amount of linolenic acid (58.4%) comparing with that in order vegetable oils. Little arachidonic acid was detected in vegetable oil, whereas none in animal fat and. fish oil.

• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.158-173
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• 2012

The objectives of this study were to analyze the longitudinal gradient and temporal variations of water quality in Daecheong Reservoir in relation to the major inflowing streams from the watershed, during 2001~2010. For the study, we selected 7 main-stream sites of the reservoir along the main axis of the reservoir, from the headwater to the dam and 8 tributary streams. In-reservoir nutrients of TN and TP showed longitudinal declines from the headwater to the dam, which results in a distinct zonation of the riverine ($R_z$, M1~M3), transition ($T_z$, M4~M6), and lacustrine zone ($L_z$, M7) in water quality, as shown in other foreign reservoirs. Chlorophyll-a (CHL) and BOD as an indicator of organic matter, were maximum in the $T_z$. Concentration of total phosphorus (TP) was the highest (8.52 $mg\;L^{-1}$) on March in the $R_z$, and was the highest (165 ${\mu}g\;L^{-1}$) in the $L_z$ on July. Values of TN was the maximum (377 ${\mu}g\;L^{-1}$) on August in the $R_z$, and was the highest (3.76 $mg\;L^{-1}$) in the $L_z$ on August. Ionic dilution was evident during September~October, after the monsoon rain. The mean ratios of TN : TP, as an indicator of limiting factor, were 88, which indicates that nitrogen is a surplus for phytoplankton growth in this system. Nutrient analysis of inflowing streams showed that major nutrient sources were headwater streams of T1~T2 and Ockcheon-Stream of T5, and the most influential inflowing stream to the reservoir was T5, which is located in the mid-reservoir, and is directly influenced by the waste-water treatment plants. The key parameters, influenced by the monsoon rain, were TP and suspended solids (SS). Empirical models of trophic variables indicated that variations of CHL in the $R_z$ ($R^2$=0.044, p=0.264) and $T_z$ ($R^2$=0.126, p=0.054) were not accounted by TN, but were significant (p=0.032) in the $L_z$. The variation of the log-transformed $I_r$-CHL was not accounted ($R^2$=0.258, p=0.110) by $I_w$-TN of inflowing streams, but was determined ($R^2$=0.567, p=0.005) by $I_w$-TP of inflowing streams. In other words, TP inputs from the inflowing streams were the major determinants on the in-reservoir phytoplankton growth. Regression analysis of TN : TP suggested that the ratio was determined by P, rather than N. Overall, our data suggest that TP and suspended solids, during the summer flood period, should be reduced from the eutrophication control and P-input from Ockcheon-Stream should be controlled for water quality improvement.

• Journal of Life Science
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• v.12 no.6
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• pp.700-707
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• 2002

To study the characteristics of organic and nutrient removal by Bacillus species at high COD concentration of influent, three lab-scale batch reactors(R1, R2, R3), each of which has different substrate composition, were operated. More than 95% of $NH_4^+$-N and $COD_{cr}$, concentrations were removed under an aerobic condition, and their removal efficiencies were found to be 22.6 and 90.5%(R1), 23.9 and 65.8%(R2), 30.2 and 86.4%(R3), respectively. The removal efficiency of $NH_4^+$-N was high when an enough amount of $NO_3^{-}$-N was supplied, and that of $COD_{cr}$. was low when a high concentration of initial $NO_2^{-}$-N was added. The amount of carbon utilized in denitrification was a little. In all reactors,$NO_3^{-}$-N was removed under an anoxic condition, but in the R3 reactor, 10% of $NO_3^{-}$-N could be removed even undo, an aerobic condition. The removal efficiencies of TN and TP were 41.8 and 49.5%(R1), 40.1 and 35.8%(R2), 47.0 and 57.6%(R3), respectively. Alkalinities destructed under an aerobic condition for each reactor were 4.96, 5.41 and 3.93 mg/L (as $CaCO_3$) per each gram of $NH_4^+$-N oxidized, respectively, while 3.06, 3.17 and 2.60 mg/L (as $CaCO_3$) of alkalinities were produced for each gram of ,$NO_3^{-}$-N reduced to $N_2$. The SOUR were found to be 38.5, 52.7 and 42.0 mg $O_2$/g MLSS/hr, which indicated that Bacillus sp. had a higher cell activity than activated sludge. The OLR and sludge production were estimated to be 0.69 and 0.28(Rl), 0.77 and 0.20(R2), 0.61 kg COD/$m^3$/day and 0.25 kg MLSS/kg COD(R3), respectively. From the N-balance, the highest percentage(40.9%) of nitrogen lost to $N_2$ was obtained in the R3 reactor. From all the results, the possibility of aerobic denitrification Bacillus sp. has been shown and the B3 process seemed to have two advantages: a little amount of carbon was required in denitrification and not much amount of alkalinity was destructed under an aerobic condition.

• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.1-5
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• 2005

Continuous monocropping of Chinese cabbage in Gangwon highland increased gravel and sand contents due to surface soil erosion. Nutrient leaching and Chinese cabbage growth were investigated with different treatments of gravel contents and nitrogen application levels by using $0.5m^2$ Wagner pots. Gravel contents were 0, 10, 30, 50, 70, and 90%(w/w), nitrogen application levels were 60, 120, and 240 kg/ha, and manure compost application rate was 15 ton per hectare, respectively. Wagner pots were filled with loamy sand soil mixed with 5 cm-sized gravels. Fresh weight of Chinese cabbage was decreased as gravel contents in soil increased, and particularly severely decreased at 240 kg-N/ha. Yields of Chinese cabbage were remarkably decreased at the rate of 60 kg-N/ha with 30% gravel content and 120 kg-N/ha with 50% gravel content. Most of Chinese cabbages were severely wilted by heavy N application at the rate of 240 kg-N/ha in the middle of growth stages regardless of gravel contents, while about 50% of Chinese cabbage showed wilting symptom in the treatment of more than 50% of gravel contents and 120 kg-N/ha. N content in leachate increased as gravel content and N application increased. The relationship between gravel content and N contents showed linear regression: N in leachate = 0.014(gravel content) -0.039 (r = 0.961). Particularly, $NH_4-N$ contents in leachates with more than 30% gravel content and 240 kg-N/ha ranged from $139{\sim}339mg/L$. Chinese cabbage growth in loamy sand soil containing 30%, and 50% gravel contents could be adversely affected by N application at the rate of 240, and 120 kg-N/ha, respectively.

• Korean Journal of Ecology and Environment
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• v.34 no.1 s.93
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• pp.30-44
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• 2001

In this study limnological characteristics of Lake Juam was surveyed from June 1993 to May 1994 in order to provides important information regarding water resources. Secchi disc transparency, epilimnetic chlorophyll a (chi-a), total nitrogen (TN), total phosphorus (TP) concentration and primary productivity were in the range of $2.0{\sim}4.5\;m$, $0.9{\sim}13.6\;mgChl/m^3$, 0.78$\{sim}$2.32 mgN/l, $11{\sim}56\;mgP/m^3$, $270{\sim}2.160\;mgCm^{-2}\;day^{-1}$, respectively. On the basis of TP, Chl-a and Secchi disc depth, the trophic state of Lake Juam can be classied as mesotrophic lake. The phosphorus inputs from non-point sources are concentrated in heavy rain episodes during the monsoon season. As a result, phosphorus concentration are higher in summer than in winter. TP loading from the watershed were estimated to be $0.9\;gPm^{-2}yr^{-1}$, which correspond to a boundary of the critical loading ($1.0\;gPm^{-2}yr^{-1}$) for eutrophication. From the results of the algal assay, both phosphous and nitrogen act as limiting nutrients in algal growth. The seasonal succession of phytoplankton community structure in Lake Juam was similar to that observed in other temperate lakes. Diatoms (Asterionella formosa and Aulacoseira granulate var. angustissima)fujacofeira BraHuJafa uar. aHgusHrsiaia) weredominant in spring and winter, cyanobacteria) were dominant in warm season. The organic carbon, nitrogen and phosphorus content of lake sediment were $9.5{\sim}14.0\;mgC/g$, $1.01{\sim}1.82\;mgN/g$ and $0.51{\sim}0.65\;mgP/g$, respectively. The allochthonous organic carbon loading from the watershed and autochthonous organic carbon loading by primary production of phytoplankton were determined to be 1,122 tC/yr and 6,718 tC/yr, respectively. To prevent eutrophication of Lake Juam, nutrient management of watershed should be focus on reduction of fertilizer application, proper treatment of manure, and conservation of topsoil as well as point source.