• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.677-686
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• 2018

This study was carried out to determine the effect of Kluyvera sp. CL-2 (KACC 91283P) on the growth of watermelon (Citrullus vulgaris L.). The study consisted of three treatments, no treatment (NT), twice application of Kluyvera sp. CL-2 before transplanting (KC1), and five times application around transplanting (KC2). We determined the chemical properties of soil before and after the treatments, and compared the growth characteristics of watermelon among treatments. The treatment of Kluyvera sp. CL-2 at $1.0{\times}10^6cfu\;mL^{-1}$ significantly increased available $P_2O_5$. The organic matter showed to increase for all treatments, while soil pH, exchangeable Ca and Mg tended to decrease for all treatments. The leaf width was increased by 11.6% for KC1 and 26.2% for KC2 compared to NT. But there were no significant differences in yield, leaf length, fruit weight, fruit length, fruit width, and pericarp thickness among treatments. The contents of free sugars such as fructose and glucose were increased by microbial treatments but sucrose was not different from NT. The content of glucose in watermelon was increased by 13.8% in KC1 and 12.8% in KC2 compared to NT. The content of fructose increased by 14.6% in KC1 and by 39.8% in KC2 compared to NT. The results from the study imply that Kluyvera sp. CL-2 can be used to increase sugar content in watermelon.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.736-745
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• 2016

This research was conducted to evaluate the impact of various pre-planting $NH_4{^+}:NO_3{^-}$ ratios on the growth of plug seedlings of 'Bool-am No.3' Chinese cabbage. With fixation of the pre-planting N concentrations to $300mg{\cdot}kg^{-1}$ in a peatmoss+coir dust+perlite (3.5:3.5:3, v/v/v) medium, the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, 100:0. Then, the each of root media containing various ratios of $NH_4{^+}:NO_3{^-}$ as well as equal concentrations of other essential nutrients was packed into 72-cell plug trays. After seeds of 'Bool-am No.3' Chinese cabbage were sown, the seedling growths were measured 2 and 4 weeks after sowing. The weekly analysis of root media and end-crop tissue analysis for mineral nutrients 4 weeks after seed sowing were also conducted. As the seedlings grew up, the pH of the root media increased, however ECs in all treatments of $NH_4{^+}:NO_3{^-}$ ratios decreased. The concentrations of K, Ca and Mg in root media were higher in the treatments of $NH_4{^+}:NO_3{^-}$ (100:0) and $NH_4{^+}:NO_3{^-}$ (73:27) than those of $NH_4{^+}:NO_3{^-}$ (0:100) and $NH_4{^+}:NO_3{^-}$ (27:73) 2 weeks after seed sowing. But the concentrations of K, Ca, Mg and Zn were get lowered in all treatments and the differences among treatments were not significant 4 weeks after sowing. The highest $NH_4{^+}$ and lowest $NO_3{^-}$ concentrations of the root media were observed in the $NH_4{^+}:NO_3{^-}$ (100:0) among all treatments. Contrary to these, the treatment of $NH_4{^+}:NO_3{^-}$ (0:100) had the lowest $NH_4{^+}$ and highest $NO_3{^-}$ concentrations. The seedling growth in terms of fresh and dry weights of aerial part were the highest in the treatment of $NH_4{^+}:NO_3{^-}$ (23:73) at 2 weeks after sowing and those of $NH_4{^+}:NO_3{^-}$ (50:50) at 4 weeks after sowing. The survival rate of seedlings in $NH_4{^+}:NO_3{^-}$ (100:0) treatment were 19% and the growth of aerial part 4 weeks after sowing was the poorest among all treatments tested. The results mentioned above indicate that the pre-planting $NH_4{^+}$ ratio in inert media should not exceed 25% in plug stage 1 through 3 (until 2 true leaf development) and 50% in plug stage 4 (after 2 true leaves to transplant).

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.194-205
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• 1999

Hydrogeochemical variation and environmental isotope at the some abandoned metal mine (Sanggok, Keumsil, Jangpung and Samdeok) creeks of the Hwanggangri mining district were carried out based upon the physicochemical properties for surface water collected of February in 1998. Hydrogeochemical composition of the all water samples are characterized by the relatively significant enrichment of Ca$^{2}$, alkaline ions, N $O_3$$^{－}$ and Cl$^{－}$ in normal surface water, whereas the surface waters near the mining area are relatively enriched in Ca$^{2+$, Mg$^{2＋}$, heavy metals. HC $O_3$$^{－}$ and S $O_4$$^{2－}$. Surface waters of the mining creek have low pH, high EC and extremely high concentrations of TDS compared with surface water of the non-mining creeks. The range of $\delta$D and $\delta$$^{18}$O values (SMOW) in the waters are shown in －65.0 to－71.2$\textperthousand$ and －9.1 to－10.2$\textperthousand$. The d($\delta$D－$\delta$$^{18}$O) value with those of water samples ranged from 7.3 to 10.9. These $\delta$D and $\delta$$^{18/}$ of the acid mine water are more heavy values than those of surface water. The values have revealed the positive correlation between isotopic compositions and major elements, because those $\delta$D and $\delta$$^{18}$O values increase with increasing TDS. HC $O_3$$^{－}$ , S $O_4$$^{2－}$ and Ca$^{2＋}$ concentration. Using WATEQ4F, saturation index of albite calcite, dolomite and mostly clay minerals in water of the mining area show undersaturated and progressively evolved toward the equilibrium condition due to fresh water mixing, however, surface waters of the non-mining area are nearly saturated and/or supersaturated. Geochemical modeling showed that mostly toxic heavy metals within water in the mining creek may exist largely in the from of metal-sulfate (MS $O_4$$^{2－}$), free metal (M$^{2＋}$/), C $O_3$$^{－}$ and/or OH$^{－}$ complex ions. Based on the geology, water chemistry and environmental istopic data the water compositions from the Sanggok and Keumsil mine creek (consist mainly of Cambro-Ordovician carbonate rocks of the Cho-seon Supergroup) show higher PH, Ca$^{2＋}$, Mg$^{2＋}$ , HC $O_3$$^{－}$ and more heavy $\delta$D and $\delta$$^{18}$O values than those from the Jangpung and Samdeok mine creek (consist of age -unknown metasedimentary rocks of the Ogcheon Supergroup and/or Jurassic grani-toids), but each of these waters represents a similar hydrogeochemical evolution path by the mine water mixing.

• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.305-312
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• 2007

It was the investigated the response to metalaxyl of Phytophthora capsici isolates collected in 2005 and 2006. With effective concentrations ($EC_{50}$) of metalaxyl causing 50% growth inhibition, resistance baseline was determined as more than $1.0\;{\mu}g\;mL^{-1}$. Based on the resistance baseline, isolation frequency (%) of P. capsici resistant to metalaxyl was 29.0% and 218% in 2005 and 2006, respectively. Among the isolates of P. capsici obtained in 2006, the isolation was variable; 33.3% in Chungnam, 26.3% in Chungbuk and 11.1% in Gyeongbuk. Two isolates of metalaxyl-sensitive (MS) and too isolates of metalaxyl-resistant (MR) P. capsici were selected and then used to investigate the activity of metalaxyl to their development stages. Even though there was a difference in mycelial growth inhibition by metalaxyl between MS and MR isolates, the fungicide was not active or nearly to sporangium germination, zoospore release, and zoospore germination of both MS and MR isolates. However, the fungicide showed weak activity against sporangium germination and zoospore release of P. capsici, not related with its resistance. Also, it was not inhibitory to zoospore germination of both resistant and sensitive isolates. In a greenhouse test, it showed 100% of control value against P. capsici 06-86 sensitive to metalaxyl, when it was applied by soil-drenching at $25\;{\mu}g\;mL^{-1}$. However, 06-130 and 16-155 resistant to metalaxyl showed less than 20% of control value.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.2
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• pp.59-65
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• 1999

Both the groundwater changes due to different pumping rates and the geochemistry of thermal waters in the Suanbo area are considered in this study. The observation of groundwater level change since 1991 shows that the change is directly correlated with pumping rates of thermal waters and reveals the retardation of ca. 5 weeks after pumping. The hydrogeological aquifer in the area is under reducing condition. The thermal waters are of Na-HCO$_3$ type. and are alkaline (pH=8.5∼8.7) with low TDS values (274∼284 mg/l) and high concentrations of Na (68∼72 mg/l). F (6.4∼8.9 mg/l), and HCO$_3$(136∼146 mg/l). Oxygen and hydrogen isotope ratios of thermal water indicate a meteoric water origin. The activities of Rn-222 and Ra-226 in both thermal water and local groundwater were determined to delineate possible geochemical controls on the Rn-222 and Ra-226. The Rn-222 concentrations are several orders of magnitude greater than the Ra-226 concentrations. The concentrations of Rn-222 range from 190 to 7.490 pCi/1 with an average of 2,522 pCil/l. and those of Ra-226 average 0.32 pCi/1 with the range from 0.25 to 0.42 pCi/1. The concentrations of Rn-222 and Ra-226 are inversely correlated with EC and alkalinity. The pH it positively correlated with Ra-226. The correlation between Rn-222 and Ra-226 is poor. Thermal waters in the study area are produced from highly fractured phyllite. The thermal water qualify. CSAMT (controled-source audiofrequency magnetotelluric) prospecting, and petrological evidences, however, indicate that the heat is possibly transmitted through deep normal faults reaching a deep granite batholith, and the phyllite acts only as a groundwater pathway.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.36-43
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• 2020

BACKGROUND: Wicheon watershed has the largest irrigation area among the mid-watershed of Nakdong river. However, no investigation of irrigation water quality has been conducted on the Wicheon watershed, which evaluates the effects on the soil quality and crop cultivation. Therefore, this study aims to provide various assessments of water quality of Wicheon watershed as the scientific basic data for efficient agricultural activities. METHODS AND RESULTS: Water sampling was performed in five locations of the first tributaries of Wicheon. Wicheon watershed showed clean water quality with very low organic matters and safe water quality from metals at all points of investigation. It was estimated that the natural chemical components of Wicheon watershed were originated from water-rock interaction in Gibbs diagram. All samples were concentrated in the type of Ca-HCO₃-Cl in the Piper diagram. The quality of irrigation water was evaluated with sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), and percent sodium (%Na). The values of these water quality indices were in the range of 0.37-0.67, -2.11--0.24, 41.13-84.52% and 11.28-21.84%, respectively, and were classified as good grades at all sites. CONCLUSION: The water quality of Wicheon watershed was very low in salt, indicating good irrigation water suitable for growing agricultural products. We hope that the results of this study will be used as the basic data for the cultivation of agricultural products and promotion of their excellence.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.407-414
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• 2018

This study was aimed to evaluate the effect of application method and concentration of gibberellin $A_3$ ($GA_3$) on the growth, runner production, and seedling quality of strawberry plants (Fragaria ${\times}$ ananassa Duch. cv. Maehyang) during nursery period. The mother plants of strawberry were transplanted in pot ($64{\times}27{\times}18cm$) filled with commercial growing medium on March 20, 2018. $GA_3$ concentration was applied as 0, 50, 100 or $200mg{\cdot}L^{-1}$ with spray or drench to 45 mL per plant at 4 weeks after transplanting, respectively. Nutrient solution was supplied with the EC $1.5dS{\cdot}m^{-1}$ after the transplanting and supplied 350 mL per pot twice a day (15 min per one time) after rooting. The growth characteristics of mother plants of strawberry were measured at 7 weeks after treatment, and growth characteristics of daughter plants of strawberry were measured at 10 weeks after treatment. Runner length and diameter of mother plant was the longest or thickest in the spray with $200mg{\cdot}L^{-1}$ than the other treatments, respectively. Soil-plant analysis development (SPAD) value of mother plant was the lowest in spray with $200mg{\cdot}L^{-1}$. However, leaf length, leaf width, and crown diameter showed no significant differences in all treatment among application method and concentration of $GA_3$. As the concentration of $GA_3$ increased, physiological disorder like stretchiness of crown occurred more. The physiological disorder was the most occurred in spray treatment with $200mg{\cdot}L^{-1}$, but drench treatment occurred less than spray treatment. The number of runners and daughter plants increased with increasing concentration of $GA_3$ regardless of application methods. In the growth characteristics of the daughter plants, leaf length and leaf width of first daughter plant, plant height, crown diameter, leaf area and SPAD value of second daughter plant, and plant height of third daughter plant were the significantly greatest in drench with $100mg{\cdot}L^{-1}$ treatment. This results indicate that growth and runner production of mother plants and growth of daughter plants of strawberry were the best achieved by drench application in the $100mg{\cdot}L^{-1}$ $GA_3$.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.137-152
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• 2009

Present experiment was conducted at the field of Gyeongnam Agricultural Research and Extension Services in Jinju city for two continuous cropping seasons to develop several adaptable and valuable year-round forage-producing system for elevating self-sufficiency and dollar-saving by reduced importing of crude forage. Twenty cropping systems were tested in experiment using whole crop barley (WCB), oat, rye, Italian ryegrass (IRG), and triticale in winter season and com, sorghum, sorghum ${\times}$ sudangrass hybrid, and oat in summer time. Sorghum ${\times}$ sudangrass hybrid showed highest fresh forage yield among experimented summer season crops, and followed com. Com produced the most dry matter yield, and followed sorghum${\times}$sudangrass hybrid, sorghum and oat in order. There was no significant effect of former winter crops on fresh and dry matter production succeeding summer time crops. Among winter season forage crops tested, oat showed the highest fresh and dry matter when clipped on mid-May, and followed triticale, IRG, rye and WCB. Winter-time cultivated crops showed no clear effect on the growth and forage (fresh and dry matter) producing ability of following summer crops. There was the most protein content in oat plant among summer season planted crops, and in sorghum for acid detergent fiber (ADF) and in sorghum ${\times}$ sudangrass hybrid for neutral detergent fiber (NDF), respectively. While, com showed highest value of relative feed value (RFV) and total digestive nutrients (TDN) among those crops. Among winter crops, the highest crude protein was in oat plant showing no significant differences of ADF and NDF, while, relatively higher value of RFV was recognized with rye and triticale. Also, triticale contained more TDN as compare to other forage crops. The cropping combinations such as com followed by (fb) rye and maize fb triticale were regarded as promising systems having higher dry matter producing ability among tested combinations. Considering TDN producing potential, the combinations with sorghum ${\times}$ sudangrass hybrid fb triticale andlor rye were would be suitable ones, coincidently. There was a tendency which elevating pH, electric conductivity (EC) and organic matter (OM) contents in soil after experiment comparing to before planting. More crude protein content in plant was shown at mid-May clipping as compared to the forage at April cut in all winter season grown crops. ADF and NDF contents were increased by delayed clipping showing decreased tendency of RFV and TDN in plant. In conclusion, many cropping systems would be available using above mentioned forage crops according to farmer's conditions and scale, etc.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.271-282
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• 2010

This study was conducted to investigate the effects of concentrated pig slurry and byproduct liquid fertilizer on the growth and yield of chinese cabbage. The experiment was conducted in a rain-shelter house which was installed in the agriculture farm. Plants were fertilized with concentrated slurry (CS), byproduct fertilizer (BF), mixture of concentrated slurry and byproduct liquid fertilizer (CS+BF), combined organic and chemical fertilizer (CS+BF+BF) and chemical fertilizer (CF) as control. 1. The pH level of byproduct liquid was decreased from the 3rd to the 7th day and increased 9 day to 14th day, but pH of concentrated slurry (CS) was not greatly varied. EC of concentrated slurry (CS) and byproduct liquid was increased gradually during the fermentation. 2. The concentrated slurry (CS) was low in phosphorus, calcium, magnesium, rich in potassium and unbalanced as a low nitrogen and high potassium. But byproduct liquid fertilizer was balanced in nitrogen and potassium ratio. 3. The leaf number, head height, head width of chinese cabbage in treatment with organic and chemical fertilizer (CS+BF+N) showed significant difference compared with control. The plant and head weight of chinese cabbage in treatment of concentrated slurry was severely decreased, but that in treatment organic and chemical fertilizer (CS+BF+N) were increased 8, 10% compared with control chemical fertilizer (CF), respectively. 4. The content of $K_2O$ in plant tissue and in soil was increased after using concentrated slurry. On the other hand, mineral content of except $K_2O$ did not differ significantly between any of the treatments. In conclusion, organic and chemical fertilizer (CS+BF+N) could improve growth and head weight of chinese cabbage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.55-62
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• 2019

Rapeseed meal, which is a byproduct of rapeseed oil extraction, improves crop productivity by supplying nutrients to the soil. The present study aimed to manufacture fermented rapeseed meal compost using two effective microbial agents and evaluate their efficiency as fertilizer. To types of fermented rapeseed meal, manufactured using either a bio-carrier or microbial agent, showed no differences in pH, electrical conductivity (EC), and total nitrogen content. However, the contents of $NH_4-N$ and $NO_3-N$ as inorganic nitrogen were increased by 5.6 times and 1.5 times, respectively, after 5 d of fermentation. Rapeseed meal fermented for 5 d was applied to tomato a basal fertilizer and after eight weeks, the plant height increased in all fermented rapeseed treatments compared to that in the chemical fertilizer treatment, and also the quantum yield of photosystem II (PS II) showed the same trend. The total nitrogen content of tomato leaves treated with a microbial fermented rapeseed meal was twice as high as that of that treated with a chemical fertilizer. It was confirmed that the increase in the tomato height was an effect of the rapeseed meal containing inorganic nitrogen, which can easily be absorbed by plants. From these results, it is considered that fermented rapeseed meal manufactured with an effective microbial agent for 5 d showed the highest inorganic nutrient content and greatest growth enhancement in tomato.