• Asian-Australasian Journal of Animal Sciences
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• v.31 no.3
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• pp.457-466
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• 2018

Objective: The present study aimed to assess the nitrogen (N) use efficiency of acidified pig slurry for regrowth yield and its environmental impacts on perennial ryegrass swards. Methods: The pH of digested pig slurry was adjusted to 5.0 or 7.0 by the addition of sulfuric acid and untreated as a control. The pig slurry urea of each treatment was labeled with $^{15}N$ urea and applied at a rate of 200 kg N/ha immediately after cutting. Soil and herbage samples were collected at 7, 14, and 56 d of regrowth. The flux of pig slurry-N to regrowth yield and soil N mineralization were analyzed, and N losses via $NH_3$, $N_2O$ emission and $NO_3{^-}$ leaching were also estimated. Results: The pH level of the applied slurry did not have a significant effect on herbage yield or N content of herbage at the end of regrowth, whereas the amount of N derived from pig slurry urea (NdfSU) was higher in both herbage and soils in pH-controlled plots. The $NH_4{^+}-N$ content and the amount of N derived from slurry urea into soil $NH_4{^+}$ fraction ($NdfSU-NH_4{^+}$) was significantly higher in in the pH 5 plot, whereas $NO_3{^-}$ and $NdfSU-NO_3{^-}$ were lower than in control plots over the entire regrowth period. Nitrification of $NH_4{^+}-N$ was delayed in soil amended with acidified slurry. Compared to non-pH-controlled pig slurry (i.e. control plots), application of acidified slurry reduced $NH_3$ emissions by 78.1%, $N_2O$ emissions by 78.9% and $NO_3{^-}$ leaching by 17.81% over the course of the experiment. Conclusion: Our results suggest that pig slurry acidification may represent an effective means of minimizing hazardous environmental impacts without depressing regrowth yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.452-459
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• 2003

A new demand for vegetable peanut (Arachis hypogaea L.) in Korea has increased farmers interest in growing vegetable peanut. Compared to grain peanut production, vegetable peanut production enables the growth period to be shortened by 20 or 30 days and farmers to adopt various cropping systems and to return crop residues in the soil. With the purpose of establishing desirable cropping systems for sustainable vegetable peanut production, three field experiments were conducted from 2000 to 2001 at Milyang, the southeastern part of Korea. Main focuses were given into the effect of cropping systems for vegetable peanut production on each crop's yield and soil sustainability. The cropping systems investigated were single vegetable peanut, peanut-radish-green barley, peanut-barley, and peanut-garlic cropping system, with or without crop residue incorporation in the soil. Among the cropping systems investigated for sustainable vegetable peanut production, peanut-only and peanut-radish-green barley cropping systems showed vulnerable to diseases and lodging while peanut-barley and peanut-garlic cropping systems showed higher stability in response to diseases and lodging, consequently leading to higher yield potential of vegetable peanut production. In the peanut-barley cropping system, both barley and peanut residues returned to the soil played an important role in soil improvement as well as in significantly increased grain yield of peanut and barley. A particular notice was taken to the pronounced increase in Trichoderma population and the amount of nitrogen mineralization induced by the returned barley residue. Soil structure, compactness, pH, and fertility were positively influenced by the returned crop residues, which apparently increased sustainability in vegetable peanut production systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.579-592
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• 2020

This study was designed to assess the water quality and phytoplankton community including chlorophyll a in blood cockle (Tegillarca granosa) farms in May, August and November of 2017 in the northwestern Yeoja Bay, Korea. As a result, the seasonal characteristics of water types by water temperature and salinity were clear. Nutrients were abundant in silicate throughout the season, but phosphate was scarce in spring and summer, and nitrogen sources were scarce in autumn. The species composition of phytoplankton community was a very simple distribution, and the standing crop was also very low. The annual dominant species is dominated by the diatoms, with Skeletonema costatum-ls, Nitzschia longissima in spring, Pleurrosigma normanii, Coscinodiscus gigas in summer, and N. longissima, Pseudonitschia pungens, Chaetoceros curvisetus, Eucampia zodiacus in autumn. In summer the results were different from other coastal waters of Korea. The principal component analysis(PCA) and correlation analysis showed that the characteristics of water quality and biological environments differed according to the season. Furthermore, it was determined by the supply of materials through fresh water on land, seawater congestion caused by the refueling of surface sediments with lower depth, and the balance of biological production and mineralization of organic matters in blood cockle farms.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.272-279
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• 2002

A field experiment was conducted to investigate the effect of N-use efficiency and rice yield by rapeseed cake(organic fertilizer) application at panicle initiation stage in machine transplating cultivation from 1999 to 2000. The rice yield increased by 4% in "50% rapeseed cake application", by 2% in "30% rapeseed cake application" at panicle initiation stage, respectively. Amount of fertilizer N uptake was high according to increasing amount of rapeseed cake application at panicle initiation stage compared with conventional treatment, but percentage recovery of fertilizer N was higher in 30% rapeseed cake application than in 50% rapeseed cake application at panicle initiation stage. Thus, this result was thought that there was more adventageous in 30% rapeseed cake application than 50% rapeseed cake application at panicle initiation stage in the fertilizer reduction or N-use efficiency respects in rice paddy.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.178-185
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• 1995

Air pollution effects on soil chemical properties, denitrifying and sulfur-reducing bacteria and lichens were examined around the Yeochun industrial estate. Soil samples were collected from mountain and/or mountain edges around the Namhae Chemical Corp., which is located at the southern edge of the estate, and sampled plots which were selected at 2km, 4km, 6km, 8km, and 10km apart from the industrial estate. The forest soils around the industrial estate could be classified into the Reddish yellow forest soil group, but soil pH was quite lower than the soils of the group. Because of the extremely low soil pH, microbial activity related to mineralization of organic matter was expected to be very low even though C/N ratio ranged from 15 to 20. As a result, soil organic matter and total nitrogen in soil were relatively high compared to the soils of the group. In general, soil chemical properties around the industrial estate up to 4km apart from the estate were significantly different from the rest(more than 6km apart from the estate) possibly due to air pollution. However, denitrifying bacteria and sulfur-reducing bacteria did not show significant differences in colony forming units by the distances from the industrial estate. By the way, lichens showed distinct differences in frequencies and coverages by the distances from the industrial estate possibly due to air pollution. The corticolous lichens showed more sensitive response to the air pollution compared to the saxicolous lichens.

• Korean Journal of Organic Agriculture
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• v.20 no.1
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• pp.59-70
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• 2012

This experiments was conducted to investigate the influence on the growth of Sorghum ${\times}$ Sudangrass hybrid by use of various organic fertilizer and investigated their productivity, feed value and stock carrying capacity. In the results, the application of fermented poultry manure showed 93.6ton/ha, 19.6ton/ha, 1.12ton/ha, 11.31ton/ha of fresh yield, dry matter yield, crude protein (CP) yield and total digestible nutrients (TDN) yield but there were no significant differences with the application of poultry by-product compost (poultry manure with sawdust) and swine by-product compost (swine manure with sawdust). And the average value of $K_{CP}$ and $K_{TDN}$ showed the highest one as 9.45head/ha/yr in the application of fermented poultry manure. However, organic matter content of fermented poultry manure to the lower portion of 32.1% compared to other organic fertilizers could imagine that mineralization of fermented poultry manure was fairly advanced and plant used most of nitrogen in fermented poultry manure, so productivity of Sorghum ${\times}$ Sudangrass hybrid was shown more than other organic fertilizers. If other organic fertilizers use continuous, this difference can be considered to be reduced further. As a result, fermented poultry manure is better than other organic fertilizers in productivity, feed value and stock carrying capacity due to the higher content of mineralizable matters. In addition, mixing poultry manure with cow and swine manure is better choice because cow and swine manure will meet a low organic matter in poultry manure.

• 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.

• Korean Journal of Environmental Agriculture
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• v.15 no.3
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• pp.296-305
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• 1996

Chemical characteristics of paper sludge, degradation of the sludge in soil and $CO_2$ generation, and changes of nitrogen and heavy metals in soil treated with the sludge were investigated. The results obtained was summarized as follows: 1. Degradation rate of paper sludge in soil was 19% at room temperature, and 28% at $incubation(30^{\circ}C)$ temperature after 12-weeks treatment. 2. T-C, T-N and the C/N ratio of the sludge in soil at room temperature were 15.5%, 0.22% and 71 respectively, and 14.5%, 0.24% and 60, respectively, at $incubation(30^{\circ}C)$ temperature after 12-week treatment. 3. $CO_2$ genaration in soil treated with 1%, 3% and 5% of the sludge was 247mg/100g, 334mg/100g and 458mg/100g, respectively, at room temperature, and 385mg/100g, 550mg/100g and 618mg/100g, respectively, at incubation temperature after 12 weeks treatment. 4. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of the sludge was 8.7%, 13.4% and 16.2%, respectively, at $incubation(30^{\circ}C)$ temperature after 12-weeks treatment. 5. The amounts of DTPA-extractable Cu, Cd, Zn, Pb, and Cr in Soil treated with paper sludge were $0.7{\sim}2.2$, $0.1{\sim}0.17$, $1.4{\sim}2.8$, $1.4{\sim}2.8$, and $0{\sim}0.7mg/kg$, respectively. Mean while, those of $HNO_3$ extractable Cu, Cd, Zn, Pb, and Cr were $7.9{\sim}10.0$, $0.6{\sim}0.9$, $17.6{\sim}34.4$, $14.7{\sim}18.5$, and $5.8{\sim}9.0mg/kg$, respectively.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.119-128
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• 2003

The two experiments in this study compared litter nitrogen (N) contents after broiler chicks were raised for 42 days. Experiment I compared litter treated with aluminum sulfate (alum) [Al$_2$(SO$_4$)$_3$ㆍ14$H_2O$] (T$_1$) with nontreated litter (T$_2$) when the broiler chicks were fed the same levels of dietary protein (23% for 0∼3 weeks, 21% for 4∼6 weeks) Experiment 2 compared the alum treated litters of broiler chicks fed high protein diets (T$_3$) having 20.4% protein for 0∼3 weeks and 19.3% for 4∼6 weeks, with lower protein diets (T$_4$) having protein levels of 18.0% for 0∼3 weeks and 17.0% for 4 6 weeks. Each treatment had four replicate cages. As shown in Table 1, T$_1$ had a significantly (P<0.0l) lower pH and significantly (P<0.05) higher total N (TN), NH$_4$-N and inorganic N (IN) than T$_2$. T$_1$ and T$_2$ had similar moisture, organic carbon (OC), NO$_3$-N and organic N (ON). Alum treatment increased available N (AN) significantly (P<0.05) from 13.75$\pm$0.0l mg/g to 14.90$\pm$0.01 mg/g and predicted available N (PAN) significantly (P<0.05) from 15.00$\pm$0.0l to 16.50$\pm$0.02. The C : N ratios were 18.84$\pm$0.40 (T$_1$) and 19.46$\pm$0.10 (T$_2$) while the C : ON ratios were 28.49$\pm$1.15 (T$_1$) and 28.34$\pm$0.20 (T$_2$) although C : N ratios or C : ON ratios did not show any difference between T$_1$ and T$_2$. In Table 2, T$_3$ had significantly (P<0.05) higher moisture, TN, NH$_4$-N, ON and IN than T$_4$, while the pH, OC and NO$_3$-N were similar in both groups. The AN of T$_3$ increased significantly (P<0.05) from 10.99$\pm$0.0l mg/g to 12.98$\pm$0.03 mg/g, while the PAN increased significantly (P<0.05) from 12.39$\pm$0.10 mg/g (T$_4$) to 14.68$\pm$ 0.30 mg/g (T$_3$). The C : N ratios increased significantly (P<0.0l) from 20.07$\pm$0.20 (T$_3$) to 24.40$\pm$0.10 (T$_3$). The C : ON ratios also increased significantly (P<0.0l) from 28.99$\pm$1.15 (T$_3$) to 35.51$\pm$0.20 (T$_4$). These current research results show increased AN contents and PAN contents in alum treated litter or with increased CP levels regardless of alum treatment. However, none of the litters in this study could initially increase mineralization.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.1
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• pp.1-10
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• 2005

The purpose of this study was to evaluate the potential of a gamma irradiation to decompose 2,4,6-trinitrotoluene(TNT) in an aqueous solution. The decomposition reaction of TNT by gamma irradiation was a pseudo first-order kinetic over the applied initial concentrations($25{\sim}100mg/L$). The dose constant was strongly dependent on the initial TNT concentration. The removal of TNT was more efficient at pH below 3 and at pH above 11 than at neutral pH(pH 5-9). The required irradiation dose to remove over 99% of TNT was 40, 80 and 10 kGy, individually at pH 2, 7 and 13. The dose constant was increased by 1.6 fold and over 15.6 fold at pH 2 and 13, respectively, when compared with that at pH 7 When irradiation dose of 200 kGy was applied, the removal efficiencies of TOC were 91, 46 and 53% at pH 2, 7 and 13, respectively. Ammonia and nitrate were detected as the main nitrogen byproducts of TNT and glyoxalic acid and oxalic acid were detected as organic byproducts. The results showed that a gamma irradiation was an attractive method for the decomposition of TNT in an aqueous solution. However, regarding the application of high energy radiation for the TNT decomposition and mineralization, an application of an acidic pH below 3 to the solution before irradiation should be considered.