• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.4
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• pp.21-29
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• 2018

The contents of total nitrogen(T-N), phosphate($T-P_2O_5$), and potash($T-K_2O$) are important factors to determine the application rate of the livestock compost to prevent nutrients accumulation and maintain their appropriate levels in arable lands. The concentrations of nutrient, organic matter, salt, water content, heavy metal in livestock compost in circulation were investigated with 659 samples from 2016 to 2017. In order to investigate the fluctuation nutrient contents of livestock composts with the same product name, 19 samples were collected and analyzed T-N, and $T-P_2O_5$, and $T-K_2O$ concentration during two years. The mean levels of T-N, $T-P_2O_5$, and $T-K_2O$ in livestock composts of from 2016 to 2017 were 1.73%, 1.88%, and 1.66%, respectively. The average contents of organic matter, water, and salt were 38.9%, 40.9%, and 1.2%, respectively. There were found that the maximum concentrations of Cr, Ni, Cu, and Zn in some livestock composts were exceeded the criteria of the official standard of commercial fertilizer. The maximum variation coefficient of T-N, $T-P_2O_5$ and $T-K_2O$ content of livestock composts was found to be 24%, 27%, and 50% on average, respectively. In order to manage the nutrients in agricultural soils, it will be reasonable that the error range of T-N and $T-P_2O_5$ content in livestock composts should be recommended to be 27% in mean as variation coefficient in case of displaying the nutrient element in liverstock compost.

• Research in Plant Disease
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• v.12 no.3
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• pp.254-259
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• 2006

Bacillus spp. isolated from mushroom medium wastes were evaluated for their biocontrol potentials on control of Sclerotinia rot of lettuce. The Bacillus isolates were more effectively obtained from waste suspension when directly added into nutrient agar(NA) medium than plating on the agar medium. Totally 42 isolates obtained from the wastes B23 and B42 showed highest antifungal activity against eight fungal pathogens such as Sclerotinia sclerotiorum, Rhizoctonia solani, Pythium ultimum, Phytophthora capsici, Fusarium oxysporum, Colletotrichum gloeosporioides, Cladosporium cucumerinum, and Botrytis cinerea and B23 and B42 were finally selected for further studies. Optimal concentration of the isolates was $10ml(10^7cfu/ml)$ to suppress the Sclerotinia rot of lettuce. Supplements such as starch, glycerol, and egg-yolk successfully maintained the bacterial population for 30 days in vitro and increased bio-control potentials against the disease. The bacterial isolate B23 alone showed 72% control value, furthermore it presented 95% control value when supplemented with 0.2% of starch, glycerol, and egg-yolk. The promising Bacillus isolates B23 and B42 were identified as Brevibacillus brevis and Bacillus stearothermophillus, respectively, based on morphological and physiological characteristics according to API database.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.357-368
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• 2012

This study was conducted to evaluate soil inorganic N concentrations and N uptake efficiency of sorghum ${\times}$ sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources from 2009 to 2011. The treatments included chemical fertilizer, compost, oilcake, alfalfa hay mulch, and control. Nutrient applications were made at rates equivalent to approximately 210 kg of actual N per hectare. The precipitation during the growth period from May to September was higher in 2011, followed by 2009, and 2010. Oilcake had the lowest C:N ratio in the raw materials. Compost treatment slowed N-mineralization rate in soil during the measured years. Soil mineral nutrition and dry matter production were not consistently affected by treatments, but the dry matter production was negatively correlated with the amount of precipitation from May to September for three years. Chemical fertilizer treatment increased N efficiency in plants in the first two years, observing with lower N efficiency in plants treated with compost for 3 years. Increased precipitation from June to August improved N efficiency in sudangrass plants treated with compost but reduced the efficiency with the chemical fertilizer. Total dry matter production and N efficiency in plants were not affected by the C:N ratio of the raw materials rather than weather condition.

• Journal of Wetlands Research
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• v.22 no.1
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• pp.49-58
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• 2020

The excessive use of fertilizer and compost in agricultural land increases the accumulation of nutrients in soil. The surplus nutrients in soil transported through surface and sub-surface flow can lead to water pollution problems and algal bloom. Moreover, nutrient accumulation and continuous crop cultivation changes the physical structure of the soil, which increases the potential of nutrient. The cultivation in the Daecheong Lake reservoir area may have a direct effect on the lake's water quality due to leaching and releasing of nutrients when water level rises. This research was carried out to analyze the physical and chemical properties of soil in the agricultural areas surrounding Daecheong Dam reservoir to provide basic data available for the establishment of Daecheong Lake water quality management measures. The soil of the Daecheong Lake reservoir was classified as sandy Loam, where surplus nutrients can be transported. Chemical compositions in the soil were found to be significantly affected by use of different fertilizer amounts. Nutrient outflow occurred during spring rainfall events from the rice paddy fields, whereas excess nutrients from summer to fall seasons originated from dry paddy fields. Nutrient outflow from dry paddy fields is mainly from sub-surface flow. Organic agricultural wastes from agricultural land and excessive vegetation inside the river was also evaluated to contribute to the increase in organic matter and nutrients of the river. The results can be used to select the priority management area designation and management techniques in the Daecheong Lake for water quality improvement.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.297-302
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• 1996

The effect of application rate of pig or chicken manure on the seasonal change of tomato(Minicarol) rhizosphere microflora was investigated by field experiment were surface soil(16cm) mixed with manures 1 weeks before transplanting. 1. Rhizobacteria population of control plot decreased 5 weeks after transplanting(WAT) than 1 WAT and 1.5~2 times higher colony counting was found in DNB(Diluted nutrient broth medium) than NB(Nutrient broth medium) at 15 WAT. 2. Rhizobacteria population at 1 WAT inereased in NB medium with the application rate of both manures but decreased in DNB with chicken manure. Colony counting in NB of 60 and 120 mg/ha treatment was 100 times higher than that of the control. However, rhizobacteria in DNB at 15 WAT(harvest stage) was much higher than that of NB. 3. Application rate did not affect fungi population 1 WAT in pig manure but decresed in chicken manure. At 15 WAT fungi population was 2 times higher than 1 WAT with chieken manure and highest in 30 mg/ha but with pig manure decreased with rate than the control. 4. Actinomycetes population at 1WAT was not different among pig manure rates and decreased with chicken manure than control. At 15 WAT population increased in all manure rates. especially in 10 mg/ha pig manure and 30 mg/ha chicken manure 4 times that 1 WAT.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.3
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• pp.63-70
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• 2018

This experiment was conducted to investigate nutrient leaching and mobility through soil column for application of biochar pellet during rice cultivation. For nutrient leaching through soil column experiment, it was also consisted with four treatments as control, 100% of pig manure compost pellet (PMCP), biochar pellet (pig manure compost:biochar, 6:4)(BP), and slow release fertilizer (SRF). For experimental results, it was observed that $NH_4-N$ concentration in the leachate was gradually decreased at pick of 35 days and $NO_3-N$ concentration was highest from 60 to 98 days after transplanting. $PO_4-P$ concentration in the leachate was shown to be lowest in the PMCP and BP. K concentration in the leachate was highest in the control, but lowest in SRF. For mobility of nutrient in soil depths, it shown that $NH_4-N$ concentrations were highest from 40 to 60cm and did not significantly different among treatments except the control. It was observed that the deeper depth, the higher concentration for $NH_4-N$ concentrations, but for $PO_4-P$ concentrations the deeper depth, the lower concentration. And also $PO_4-P$ concentration was highest in the control. For K mobility in soil, its pattern was appeared to be approximately same between the control and PMCP, and between BP and SRF. Therefore, it might be potential to be applied biochar pellet to reduce mobility of plant nutrients for rice cultivation.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1446-1458
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• 2013

The study assessed the effect of dietary supplementation of leaf meal mixture (LMM) containing condensed tannins (CT) on feed intake, nutrient utilization and performance of sheep infected with Haemonchus contortus. Eighteen adult sheep of similar age and body weight ($25.03{\pm}1.52$) were included in this study and out of these, 12 sheep were infected with single dose of infective third stage larvae of H. contortus at 2,000 larvae per sheep. The experimental sheep were allocated in three different groups' i.e. negative control (NC; no infection), control (C; H. contortus infected) and treatment (T; H. contortus infected+CT at 1.5% of the DM through LMM) and the experiment was conducted for a period of 90 d. The intake of dry matter (DM), organic matter (OM) and digestibility of DM, OM, neutral detergent fibre (NDF) and acid detergent fibre (ADF) were comparable among three animal groups. However, digestibility of crude protein (CP) and ether extract (EE) were significantly (p<0.05) higher in NC group as compared to both C and T groups. Nitrogen (N) retention (g/d or % of N intake) was significantly (p = 0.038) lower in C group as compared to T and NC groups. Daily intake (g/kg $W^{0.75}$) of digestible crude protein (DCP), digestible organic matter (DOM) and total digestible nutrient (TDN) did not differ significantly (p<0.05) in the three groups. Haemoglobin (Hb) and packed cell volume (PCV) were significantly (p<0.001) higher in treatment group as compared to control. The level of Hb and PCV reduced (p<0.001) after 30 days of experimental feeding. CT significantly (p<0.001) reduced serum urea in T group as compared to NC and C groups. Serum proteins differed significantly (p<0.01) among the three groups. The activity of serum enzymes AST, ALT, ALP and LDH were also statistically non significant (p<0.05) among treatments. The weight of abomasal lymph nodes (ALN) in T group was higher (p<0.05) than in C group. Treatment group had lower (p<0.05) total worms and fecal egg count compared to control group. It may be concluded that dietary supplementation of CT through LMM significantly improved the N retention, and inhibited the different developmental stages of Haemonchus contortus in experimental sheep.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.5
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• pp.358-368
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• 2011

Responses of plankton populations to nutrient enrichment in mesocosm experiments in Shihwa lake were simulated using FVCOM. Dissoloved oxygen module was added to the FVCOM to simulate impacts of its decreased levels. The ecological model included the major components of the pelagic ecosystem including nutrients, phytoplankton (pico-, nano-, micro-), zooplankton (two groups of protozoa, mesozooplankton), particulate organic matter, dissolved organic matter and bacteria, and was calibrated using trophodynamic data collected from Gyeonggi Bay and Shihwa Lake. The model was able to reproduce major responses of plankton populations to nutrient enrichment, including phytoplankton of different size groups, change of dominance of protozoa from < 20 ${\mu}m$ oligotrichs to scuticociliates, and reponses to bacteria and low levels of dissolved oxygen in water column of the mesocosms.

• Korean Journal of Organic Agriculture
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• v.10 no.2
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• pp.85-94
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• 2002

For Exp, 1, eighty [(DurocYorkshire)Landrace) pigs(38.63$\pm$0.68kg average initial BW) were used to evaluate the effects microbial phytase supplementation on the growth performance and nutrient digestibility in growing pigs. There were ten pigs per pen and four pens per treatment. Treatments were 1) CON(com-SBM based diet), 2) Low-P(low-P diet+500 FTU/kg microbial phytase). For overall period, ADG, ADFI and gain/feed were significantly improved(P<0.05) by supplementation of Low-P diet. Also, pigs fed Low-P diet increased N, crude ash, Ca and P digestibilities compared to pigs fed CON diet(P<0.05). For Exp. 2, sox [(DurocYorkshire) Landrace) pigs(32.7kg average initial BW) were used to evaluate the effects microbial phytase supplementation on the nutrient excretion in growing pigs. Experimental treatments were as described for Exp. 1. pigs fed Low-P diet decreased N(8.70 vs 6.43g/d), crude ash(38.13 vs. 25.33 g/d), Ca(6.03 vs. 3.93g/d) and P(4.53 vs. 2.77g/d) excretion compared to pigs fed CON diet(P<0.05). In conclusion, microbial phytase supplementation in low P diets improved growth and nutrient digestibility.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.203-218
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• 2017

The study was initiated at three rice paddy fields of each large-scale area environment-friendly agricultural district, Suncheon and Jangheung in Jeollanam-do, and Okcheon in Chungcheongbuk-do in 2016 to observe growth and nutrients in soil and rice in a season. Jangheung farm had two observed plots; conventional plots and conventional plots additionally fertilizing of 20% T-N with oil-cake. Soil pH, EC, and K concentration on June in Jangheung farm were significantly higher than those values observed in Suncheon and Okcheon farms. Annual rice T-N contents in the Jangheung farm were more than 80 g but decreased in a season. T-N concentration in rice was high in Jangheung farm but the concentrations of P and K were not significantly different among the three farms at harvest. Plant height was as low as 101 cm in Sunchon farm but high in the dry weight (72 g). Leaf SPAD was higher in Jangheung farm than those of other farms. Okcheon farm, with early cultivar 'Milky queen', produced high head rice of 93%, and high unhulled rice and the brown rice per ha. Therefore, the annual production income was as high as 26.7 million won per ha. However, nutrient (T-N + P + K) balance in Okcheon farm with high amount of fertilizer application were as high as 900 kg per ha. On the other hand, nutrient balance in Jangheung farm resulted in less than 300 kg.