• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.333-343
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• 2003

This experiment was carried out to improve the utilization of liquid pig manure (LPM) for rice at the two textures of valley soil in 2000 and 2001. The soil textures were coarse loamy and fine loamy in Sachon and Jisan series, respectively. Treatments consisted of no fertilized plot, chemical fertilized plot, LPM 150%, LPM 100%, LPM 100%+NK (top dressing) 30%, LPM 70%+NK 30%, LPM 50%+NK 50% plot. LPM was applied as basal fertilizer compare to nitrogen of chemical fertilized plot. Total N contents in the LPM were 6.0 and $4.5g\;kg^{-1}$ in 2000 and 2001, respectively. After the experiment, P and K contents of soils were not difference between chemical and LPM application plots. But heavy metal contents in soils were slightly higher in LPM application plots than in chemical fertilized plot. Immediately after LPM application, ammonia gas content was $18mg\;kg^{-1}$ in LPM 150% plot, but it was $3mg\;kg^{-1}$ in LPM 50% plot. Two days after LPM application, ammonia gas content was 3 times higher in coarse loamy than in fine loamy soil. After rotary tillage, ammonia gas was not detected at all LPM treatments. This result suggests that rotary tillage can reduce the nasty smell of LPM quickly. Inorganic nitrogen, $NO_3$ and $NH_4$, contents in water of paddy was higher at coarse loamy soil from rice transplanting to tillering stage. After that season, inorganic nitrogen contents of water were not different according to soil texture and treatments. Content of $NH_4-N$ in soil solution was higher at LPM plots than chemical fertilizer plot. Total nitrogen contents in rice plant after harvesting were higher at chemical fertilization plot than LPM application plot, but K contents showed an opposite tendency. Rice yield was decreased only in LPM plots at two soil textures. But yield was not significantly difference between chemical fertilizer and LPM+top dressing plots at coarse loamy soil and increased 5% at LPM 50%+NK 50% plot at fine loamy soil in 2001.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.211-216
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• 2017

A total of 100 seafoods commonly consumed in Gyeonggi-do were investigated to determine the concentration of lead (Pb), total mercury (Hg), methyl mercury (MeHg), cadmium (Cd) and selenium (Se). Concentration of heavy metals and selenium was measured by using mercury analyzer, ICP-MS and GC-ECD. The average content (mg/kg) of heavy metals in the seafood samples was as follows; Pb 0.0915 (0.0021-0.4490), Cd 0.0084 (ND-0.1773), and Hg 0.0412 (0.0013-0.3032). All the levels were below the recommended standards of the MFDS in Pb (0.5 mg/kg), Cd (0.2 mg/kg), Hg (0.5 mg/kg). The methylmercury was detected in the hairtail (0.0677 mg/kg) and cod (0.2941 mg/kg). After the average content of heavy metals in seafood was determined, the exposure assessment for heavy metals was conducted. Relative hazardous levels compared to PTWI were lower than the official standards of the JECFA for Pb (0.97%), Hg (3.42%) Cd (0.45%). In conclusion, the levels presented in this study are presumed to be safe for consumption.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.157-163
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• 2009

This work was conducted to investigate the amount and major compositions of excreta from broilers. One hundred fifty 1-d-old male and female Ross broilers were used in this work and ten broilers were selected to measure excreta. Average amount of excreta per broiler was 85.4 g, and average moisture content was 76.9%. N, $P_2O_5$ and $K_2O$ in excreta were 1.19, 0.29 and 0.49%, respectively. pH, $BOD_5$, $COD_{mn}$, and SS were 7.80, 42,134 mg/L, 52,668 mg/L, and 106,669 mg/L, respectively. Pb in poultry excreta was 0.803 mg/kg and highly lowed compared with the standard contents (150 mg/kg). Cd was not founded in excreta. Hg was founded in excreta as 0.002 mg/kg, but it was low compared with the standard level (2 mg/kg).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5885-5892
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• 2014

Mangrove plants serve as a sink of heavy metals and contain phenolic compounds at a high level. Therefore, with mangrove plants, recent studies to develop phytoremediation and natural antioxidants have been conducted in the commercial and academic fields. In the present study, six mangroves in Weno Island of Micronesia were investigated for their phylogenetic relationship and antioxidant activities. First, to determine the phylogenetic relationship among them, rbcL (large subunit of ribulose-bisphosphate carboxylase), one of the chloroplast genes, was used as a molecular marker. According to the data, Xylocarpus, Sonneratia and Rhizophora showed close similarity but not Excoecaria. The levels of phenolic compounds in the bark were abundant in R. apiculata and X. granatum, accounting for 1.10 mM/mg, while R. stylosa and S. alba contained the low amounts, representing 0.73 mM/mg and 0.72 mM/mg, respectively (p<0.05). In addition, bark extracts from R. apiculata, X. granatum, X. moluccensis, and E. agallocha had high antioxidant activities through the DPPH radical scavenging activity and ABTS analysis, whereas S. alba showed the lowest activities. These results suggest that the bark of R. apiculata can be used as a good source for the development of natural antioxidants.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.453-462
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• 2000

This study was carried out to know the effect of urea addition for composting of paper mill sludge(PMS). For the purpose. PMSs containing 0%, 1.5%, 3%, and 6% urea were composted at aerated static pile(ASP) for about 80day periods. During the composting, the basic physical, chemical, and biological parameters such as temperature, color. C/N ratio, cation exchange capacity, and phytotoxic test were investigated. From the measurement of the parameters, 0~3% urea-containing PMS except for 6% urea-containing PMS showed to be normally stabilized. Thus among these treatments, 0% and 3% urea-containing PMS were applied at agitated bed system(ABS), a pilot plant of a large scale, to evaluate the possibility of practical use. Considering to the changes of the parameters investigated during composting in ASP and ABS, PMS showed to be successfully stabilized in the two facilities. However, when composted with PMS and urea, even the final PMS compost stabilized for a period enough brought out the bright grayish color. So it may be necessary to add a subsidiary amendments such as animal manure to form brown-colored products.

• Journal of Life Science
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• v.27 no.10
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• pp.1185-1190
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• 2017

Insects are gaining recognition as an alternative source of protein. As a result, more and more domestic farms have begun mass rearing of edible insects. In order to produce high quality insects, studies on the development of safe and nutritious feed sources are needed. Given the cost of rearing insects, agricultural and industrial by-products are good sources for feed. The efficient utilization of these by-products can help in reducing the cost of production and preventing environmental pollution. In the current study, Citrus unshiu peel (CP), soybean curd cake (SCC), soybean oil meal (SOM), and brewers dried grain (BDG) were investigated for their effects on larval growth and development of Protaetia brevitarsis. Interestingly, the feed with 10% SCC increased larval weight by 3.5 times. For the larval period, the group of 10% SCC was significantly shorter than the control. Furthermore, minerals such as Zn, Ca, K, Mg, Na, and P were recorded to be high in 10% SCC. A total of 17 amino acids were present in 10% SCC, of which tyrosine and arginine were predominant. The heavy metal contents were very small amounts or not detected in any of the investigated groups. These findings provided a scientific basis for the utilization of soybean curd cake as a nutritional feed source to promote larval growth and produce quality insects.

• Journal of Mushroom
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• v.21 no.3
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• pp.118-125
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• 2023

We conducted an on-site application study at the livestock cooperative fertilizer plant to compare the composting period, temperature change, moisture content, and chemical properties between livestock manure compost using sawdust as a moisture regulator with those using spent oyster mushroom substrate. The composting period, moisture content, and fertilizer composition of compost containing spent oyster mushroom substrate did not differ from that of conventional compost mixed with sawdust after the first and second fermentation and post-maturation stages, it was suitable as a material for manufacturing livestock manure compost. The spent oyster mushroom substrate also lower the production cost of livestock manure compost by replacing the more expensive sawdust. The developed technology is expected to contribute towards the utilization of by-products of the oyster mushroom harvest while simultaneously producing high quality livestock manure compost.

• Journal of Marine Life Science
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• v.3 no.2
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• pp.74-80
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• 2018

Mercury (Hg) poses a threat to marine ecosystem due to continuous inflow from various industries and bioaccumulation to higher trophic level via food web. Mercury can adversely affect growth, development, reproduction and metabolism to aquatic organisms. In the present study, acute toxicity and oxidative stress markers (total glutathione content, and activities of GST, GR and GPx) were investigated in brackish water flea Disphanosoma celebensis exposed to HgCl₂ for 24 h. As results, Hg showed negative effect in survival of D. celebensis. 24 h-LC₅₀ value was determined as 0.589 mg/l (95% C.I. 0.521~0.655 mg/l). After exposure to Hg (0.08 and 0.4 mg/l) for 24 h, total glutathione content was significantly decreased, whereas GST, GPx and GR activities were enhanced. These findings indicate that Hg induced oxidative stress in D. celebensis, and oxidative stress markers may be involved in cellular defense against Hg - mediated toxicity. This study provides a better understanding of molecular mode of action of Hg toxicity in this specie and potent of molecular markers for heavy metal monitoring in marine ecosystem.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.393-398
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• 2012

We investigated the changes in chemical properties of paddy field soils at 300 different sampling sites containing 4 topography in Jeonbuk province, Korea. The soil samples were collected 43.0% from local valley and fans, 39.3% from fluvio-marine deposits, 15.0% from alluvial plains, and 2.7% from diluvium sites. The optimal values of soil properties in the total soil samples were as follows: 65.3% of total samples in soil pH value, 48.3% of total samples in cation exchange capacity (CEC) value, and 22.3% of total samples in available phosphorus content, whereas the deficient values of soil properties were 63.3% of total samples in soil organic matter (SOM) content, 75.7% of total samples in available silicate content, and 61.3%, 51.0%, and 59.3% of total samples in exchangeable $K^+$, $Ca^{2+}$, and $Mg^{2+}$ concentrations, respectively. There were different soil types in the paddy fields: that is, 34.4% immature paddy and 33.6% sandy paddy in the local valley and fans, 57.8% sandy paddy in the alluvial plains, 47.4% normal paddy in the fluvio-marine deposits, and 75.7% immature paddy in the diluvium. Soil textures were also different: 53.5% loam in the local valley and fans, 37.8% sandy loam in the alluvial plains, and 55.1% silty loam in the fluvio-marine deposits. Soil pH and SOM contents were not different among the different topographical sampling sites. However, the mean value of available phosphorus content, 224 mg $kg^{-1}$, was exceeded optimal values in the diluvium. The contents of exchangeable cations were optimal in all the sites, except exchangeable $Ca^{2+}$ contents in the local valley and fans. The contents of available silicate ranged between 112 and 127 mg $kg^{-1}$ in all the sites, which were lower than optimal value. In addition, soil pH values were proportionally correlated to the order of available silicate, exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^+$, CEC, and exchangeable $K^+$. The contents of SOM were proportionally correlated to the order of CEC, available $P_2O_5$, exchangeable $Ca^{2+}$, and available silicate. The contents of heavy metals, Cd, Cr, Cu, Ni, Pb, and Zn, were only 10% of the threshold levels of the metals, and As content was about 20 to 30% of the threshold level.

• Journal of Preventive Medicine and Public Health
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• v.26 no.4 s.44
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• pp.628-649
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• 1993

This study was conducted to investigate the factors related to the poor school performance of the elementary school children. Two schools in Taegu, one in the affluent area and the other in the poor area, were selected and a total of 175 children whose school performance was within low 10 percentile (poor performers) and 97 children whose school performance were within high 5 percentile (good performers) in each class of 2nd, 4th and 6th grades were tested for the physical health, behavioral problem and family background. Each child had gone through a battery of tests including visual and hearing acuity, anthropometry (body weight, height, head circumference), intelligence (Kodae Stanford-Binet test), test anxiety (TAI-K), neurologic examination by a developmental pediatrician and heavy metal content (Pb, Cd, Zn) in hair by atomic absorption spectrophotometry. A questionnaire was administered to the mothers for prenatal and prenatal courses of the child, family environment, child's developmental history, and child's behavioral and learning problems. Another questionnaire was administered to the teachers of the children for the child's family background, arithmatic & language abilities and behavioral problem. The poor school performance had a significant correlation with male gender, high birth order, broken home, low educational and occupational levels of parents, visual problem, high test anxiety score, attention deficit hyperactivity disorder (ADHD), poor physical growth (weight, height, head circumference) and low I.Q. score. The factors that had a significant correlation with the poor school performance in multiple logistic regression analysis were child's birth order (odds ratio=2.06), male gender(odds ratio=5.91), broken home(odds ratio=9.29), test anxiety score(odds ratio=1.07), ADHD (odds ratio=9.67), I.Q. score (odds ratio=0.85) and height less than Korean standard mean-1S.D.(odds ratio=11.12). The heavy metal contents in hair did not show any significant correlation with poor school performance. However the lead and cadmium contents were high in males than in females. The lead content was negatively correlated with child's grade(P<0.05) and zinc was positively correlated with grade (P<0.05). among the factors that showed a significant correlation with the poor school performance, high birth order, short stature and ADHD may be modified by a good family planning, good feeding practice for infant and child, and early detection and treatment of ADHD. Also, teacher and parents should restrain themselves from inducing excessive test anxiety by forcing the child to study and over-expecting beyond the child's intellectual capability.