• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.110-116
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• 2019

This study was conducted to determine the effects of a pre-planting fertilizers with various $NH_4{^+}:NO_3{^-}$ ratios in a coir dust:peatmoss:perlite (3.5:3.5:3.0, v/v/v) medium on the growth of hot pepper (Capsicum annuum L. cv. Nokkwang) plug seedling. Nitrogen levels were fixed to $300mg{\cdot}L^{-1}$ and the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, and 100:0. The 50-cell trays were filled with treatment media containing pre-plant fertilizers, then seeds were sown. After seeds were germinated, the trays were moved to greenhouse and seedlings were feed with 13-2-13 and 20-9-20 fertilizers, alternatively. The changes in pH and EC were measured every week and soil solution for nutrient concentrations were analyzed in week 0, 3, and 7. The measurements of seedling growths as well as analysis of tissue nutrient contents were also conducted in week 7. The varied $NH_4{^+}:NO_3{^-}$ ratios did not influence on the pHs of root media after incorporation of pre-planting fertilizers, but the ECs were heightened as proportion of $NH_4{^+}$ to $NO_3{^-}$ were elevated. During the raising of seedlings, the pHs rose over time in the treatments of 0:100 and 27:73 ($NH_4{^+}:NO_3{^-}$). The concentrations of all macro-elements in root media decreased gradually as seedlings grew in all treatments. The seedling growths 7 weeks after seed sowing were the highest in the treatments of 27:73 and 50:50 ($NH_4{^+}:NO_3{^-}$) and those became worse in the treatments of higher $NH_4{^+}$ ratios than 73%. In terms of inorganic element contents based on the dry weight of above ground tissue, the treatment of 0:100 showed the lowest content of Ca, Mg, Na, Cu, Mn, and Zn. Based on the results, it is desired that $NH_4{^+}$ ratio in pre-planting fertilization is maintained to be 50% or less for the raising of hot pepper plug seedlings.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.460-467
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• 2022

The purpose of this study is to enhance utilization of the waste nutrient solution (WNS) disposed at the hydroponic greenhouse. Several sets of testing were conducted to examine the effects of WNS: (a) a fertilizer effect, (b) soil column leaching, and (c) crop cultivation. The fertilizer effect test was applied in young radish cultivation by examining the growth characteristics of young radish and soil based on inorganic nitrogen according to the soil treatment of the nitrogen fertilizer (NF) and the WNS. The fertilizer effects and crop cultivation test were conducted with five treatments (A-E): A, non-treatment (water); B, 100% of NF; C, 70% of NF + 30% of WNS; D, 50% of NF + 50% of WNS; and E, 30% of NF + 70% of WNS. The soil column leaching test was conducted with three treatments: non-treatment (water), 100% of NF, 50% of WNS + 50% of NF. As a result, the chemical properties of the WNS were pH 6.0, EC 2.4dS·m^-1, total phosphorus (T-P) 28mg·L^-1, ammonium nitrogen (NH₄-N) 5.0mg·L^-1, and nitrate nitrogen (NO₃-N) 301mg·L^-1. The chemical properties of the soil were pH 5.51, EC 0.31dS/m, organic matter 2.08g·kg^-1, NO₃-N 9.64mg·kg^-1, and NH₄-N 3.20mg·kg^-1. The results of fertilizer effects showed that the ratio of 50% or less of NF and 50% or more of WNS was high in young radish growth. There was no statistically significant difference between the soil chemistry in the C-E treatments where WNS was mixed with NF and the B treatment where only NF was applied. As a result of the soil column leaching test, there was no significant difference in the concentrations of NO₃ and NH₄ in the treatment of 100% of NF and 50% of NF + 50% of WNS. The study indicates, if the mixed fertilizer of WNS and NF is applied in the soil cultivation of young radish, it will reduce the use of NF and environmental pollution. This also helps reduce production costs on farmers and increase the yield of young radish.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.224-231
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• 1984

Four kinds of soil conditioners, such as red earth, clayey tidal deposit, silty tidal deposit and tertiary deposit were evaluated for the rice growth and for the effectiveness of soil improvement in sandy paddy soil (Gangseo series) whose percolation and nutrient leaching are usually severe. Experiment was conducted at the farmer's field in Hackpo Ri, Bugog Myeon, Changyeong Gun, Gyeong Nam Province for two years (1980-1981) with using two rice varieties, Milyang 42 for 1980 and cheongcheongbyeo for 1981. For both experimental years, the grain yields were increased on the plots that were treated with soil conditioners compared with nontreated plot. The increase in grain yield was particularly high on the plots treated with clayey tidal deposit and teritary deposit. The dry weight of the plant and the uptake amount of inorganic ingredient tended to increase on the plots of clayey tidal deposit and tertiary deposit during whole rice growing season because of the residual effect of soil conditioners in the second experimental year. Cation exchange capacity, available silicate, exchangeable potassium and active iron was increased by the treatment with the soil conditoners. Especially cation exchange capacity was highest in the tertiary deposit treatment plot. Aggregation content and plastic index were increased for the all treatment plots with soil conditioner, however, hydraulic conductivity was conspicuously decreased by the tertiary deposit and clayey tidal deposit treatments.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.10
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• pp.1391-1399
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• 2009

Two hundred and sixteen 68-week-old Hy-Line brown laying hens were used in a 6-week feeding trial to compare the efficacy of phytases Optiphos (OPT) and Natuphos (NAT), which were isolated from Escherichia coli and Aspergillus niger, respectively. Hens were randomly allotted into six treatments with six replications (six layers in three adjacent cages) per treatment according to their initial BW. The hens were then subjected to one of the following dietary treatments: i) Positive Control (PC; available phosphorus (AP) 0.4%); ii) Negative control (NC; AP 0.2%); iii) NAT1 (NC+250 FTU/kg NAT); iv) NAT2 (NC+500 FTU/kg NAT); v) OPT1 (NC+250 FTU/kg OPT); vi) OPT2 (NC+500 FTU/kg OPT). Feed intake, egg production, egg quality, apparent nutrient digestibility and serum P and Ca concentration were evaluated to compare the effect of the two phytases. Feed intake and eggshell thickness were not affected by the treatments. Superior effects (p<0.05) of OPT were only observed in egg production and egg weight compared with NAT. Characteristics such as eggshell breaking strength, apparent digestibility of N, Ca and P and serum P concentration were equally increased with the supplementation of both phytases (p<0.05), where no significant difference was observed in those characteristics between PC and phytase supplementation at 500 FTU/kg. Equally effective improvements (p<0.05) were also observed in egg production and DM digestibility, where no improvements were observed (p<0.05) between the PC group and the groups with phytase supplementation at 500 FTU/kg. Equal increases in the serum Ca level were observed when the groups with phytase supplementation were compared to the PC group. Overall, the results of this study suggest that NAT and OPT are equally effective at liberating phytate-bound complexes when included in 0.2% available phosphorus diets for 68-week laying hens; either source of phytase can be fed to commercial 68-week laying hens at 500 FTU/kg to correct the negative effects associated with a 0.2% available phosphorus diet. In conclusion, either source of phytase can be fed to commercial first cycle laying hens at 500 FTU/kg to effectively replace inorganic phosphorus when economically justified.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.137-151
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• 2014

Various studies have been conducted to investigate effects of dams on river ecosystems, but less information is available regarding damming impacts on downstream denitrification. We measured denitrification enzyme activity (potential denitrification rate) and denitrifier abundances (using nirS, nirK, and nosZ as markers) in dammed headstreams of the Nakdong River in South Korea. Sediments in Phragmites-dominated riparian areas and in-stream areas across streams (dammed vs. reference) with different streambed materials (gravel and sand) were sampled occasionally. We hypothesized that (i) the higher available N and C contents in sediments downstream of dams foster larger denitrifier communities than in the reference system and (ii) differences in potential denitrification rates across the systems correspond with denitrifier abundances. Despite 30 years of different hydrological management with dams and greater inorganic N and DOC contents in sediments downstream of dams, compared to the references, abundances of denitrifier communities and potential denitrification rates within the whole sediment were not significantly different across the systems. However, nirS and nosZ denitrifier abundances and potential denitrification rates were considerably increased in specific sediments downstream of dams (gravelly riparian and sandy in-stream) with regard to flooding events and seasonal temperature variation. nirK was not amplified in all sediments. Canonical correspondence analyses (CCA) revealed that the relationship between abundances of denitrifier communities and nutrient availabilities and potential denitrification rates was a weak one.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.61-68
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• 1975

A laboratory study was conducted to determine the effect of nitrogen mineralization in accordance with addition of calcium silicate and wollastonite on the fresh soil condition. Results are summarized as follows. 1. Nitrogen mineralization due to application of silica materials was rapidly occured in Saweon sand soil than in Honam clay soil. Also wollastonite application more stimulated the nitrogen mineralization than calcium silicate. 2. Silica material application enhanced loss of applied nitrogen by denitrification due to accelerate the nitrification in Suweon sand soil. This tendency was more severe in calcium silicate applicated treatment than in wallasnonite applicated. 3. From these results, nitrogen should be applicated with organic matter to improve the supply of nitrogen nutrient to plant when silica materials were applied.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.352-356
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• 2006

Quantity of protein, amino acid, and sugar leaked from seeds was greater as the viability of seeds was dropped by the time elapsed of seed aging treatment. In the seeds with the artificial aging treatment for 20 days, 35.8 mg of protein was leaked on the 4th day after soaking, which was 6.9 times higher than that of control. Leakage of amino acid was also higher from low quality seeds treated with the aging treatment. In the seeds with the aging treatment for 20 days, $36.5{\mu}g$ fig of sugar was leaked on the 4th day after soaking, which was 2.8 times higher than that of control. The leakage of inorganic compound was higher from the low quality seeds, and leakage of total protein, amino acid, and sugar. According to .the quantity of leakage, water soluble compounds, which can be used for the assessment of seed quality without any destruction, were protein and potassium. Germination rate and percentage of seeds were dropped with the seed aging treatment, and the seed viability could be recovered by priming treatment. This phenomenon was very clear when the low quality seeds were germinated at low temperature.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.223-233
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• 2007

For this study, we analyzed spatial and temporal patterns of trophic state and water quality over the period of $2002{\sim}2005$, using the water chemistry dataset obtained from the Korea Rural community & Agriculture corporation. Most reservoirs, based on TN, showed eutrophic (about 88% of the total). About 20% of agricultural reservoirs, based on TP, showed eutrophic after the criteria of OECD (1982), while 71% and 3% were Hesotrophic and oligotrophic, respectively. Seasonal variations were evident due to the intense monsoon rain during July${\sim}$August; conductivity, COD, SS, nutrients, and chlorophyll-${\alpha}$ (CBL) increased in the postmonsoon compared to the premonsoon. TP values had positive functional relations with conductivity, COD, and CHL values. COD and SS peaked during the intense monsoon. Mean values of TP and CHL values were two times greater in the intense monsoon than the weak monsoon. The increased TP was probably due to inorganic suspended solids from point and non-point sources during the monsoon. Ratios of TN : TP had strong in- verse relations ($R^2$=0.843, p<0.001, n=34) with TP, but not with TN (p>0.05, n=34). Log10-transformed CHL increased with TP in most P-limited reservoirs $(Log_{10}TP=0.5{\times}Log_{10}CHL+0.086)$. Similarity analysis, based TN, TP, and CHL showed that three groups were separated at 90% similarity level; One group was reservoirs with high salinity nearby the seawater, and the other two groups were reservoirs with a low salinity of the inland, and intermediate salinity, respectively.

• Korean Journal of Medicinal Crop Science
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• v.12 no.6
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• pp.508-514
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• 2004

Chrysanthemum boreale M. is an important medicinal plant that has been historically used in herbal medicine and in the health food throughout East Asia. This study was conducted to investigate the influence of abscisic acid (ABA) and salicylic acid (SA) on plant growth, mineral content and effective components, such as essential oil, amino acid and cumambrin A, by means in order to increase the productivity and the quality of flowerheads in the plant. Yields of flowerheads were increased by 12.7%, 21.7% and 15.5% by ABA, SA and both treatments, respectively, as compared with the control. Inorganic nutrient content was changed by PGRs; SA treatment was increased by nitrogen, phosphorus and magnesium content but decreased by potassium of C. boreale M. flowerheads. Total content of amino acid was increased by SA but decreased by ABA treatment. Essential oil content and yields were increased to 9.7% and 33.8% by SA treatment. Moreover, the content of terpene, monoterpenoids and sesquiterpenoids, were improved by ABA treatment, especially, germacrene-D content was increased by 39.1%, as compared to control. In addition, yields of cumambrin A, sesquiterpene compound exhibiting blood-pressure activity, increased in all PGRs treatments, but its concentration in the C. boreale M. flowerheads only increased by ABA and both treatment. The experiment suggests that PGRs using ABA and SA could increase the yields and quality of C. boreale M. flowerheads.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.131-137
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• 1996

This analysis has been conducted to get some basic data of the composition of culture solution mostly in inorganic ions, and water quality in hydroponic farms in Chollabuk - do. pH range was shown from 6.00 to 7.65 and the average was 6.58. EC range was shown from 0.01 to 0.94 mS/cm and the average was 0.28 mS/cm. Na concentration ranged from 4.71 to 145.44 ppm and Cl concentration ranged from 0 to 171.80 ppm were shown and their average were 24.24 ppm and 26.33 ppm, respectively. Na and Cl concentrations were higher as 7.7%, compared to those of other farms, which could cause the salt accumulation in the substrate mats. K, Ca and Mg concentrations were ranged from 0.93 to 17.38 ppm, 2.29 to 34.30 ppm and 0.70 to 18.61 ppm, respectively. Average concentrations were 3.06 ppm in K, 13.00 ppm in Ca and 4.91 ppm in Mg. 50, and PO$_4$ concentration ranged from 0.63 to 59.79 ppm and 0 to 4.28 ppm were shown and their average were 18.11 and 0.51 ppm. Cu concentration was ranged from 0 to 0.32 ppm and 0 to 6.22 ppm in Zn concentration. Their average were 0.02 ppm and 0.52ppm, respectively.