• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.1-8
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• 2012

BACKGROUND: Organic fertilizers in watermelon cultivation are widely used to supply nutrient and organic matter. This study was conducted to investigate the effects of application rate of organic fertilizer on the watermelon growth and soil chemical properties in greenhouse METHODS AND RESULTS: The organic fertilizers used in this experiment were mixed expeller cake (MEC) and mixed organic fertilizer (MOF). The treatments were conducted with 4 levels (1.0 N, 0.7 N, 0.5 N and 0.3 N) on the basis of soil testing nitrogen fertilization (STNF) using MEC or MOF as the basal dressing, and using chemical fertilizers (CF) as the additional dressing on the rest of STNF. These fertilizations were compared to CF 1.0 N (0.3 N as the basal and 0.7 N as the additional dressing) and non fertilization (NF). The leaf area of watermelon in treatment 0.5 N and 0.3 N using MEC or MOF was similar to CF treatment. The absorbed nutrient amounts by leaf, weight and sugar contents of fruit in the 0.5 N and 0.3 N treatments were higher than other treatments. In 0.5 N and 0.3 N treatments using MEC or MOF on the basis of STNF, soil chemical properties such as electrical conductivity (EC), available $P_2O_5$ and exchangeable K concentrations after experiment showed tendency to decreasing or similar level before experiment. CONCLUSION(s): These results suggest that the MEC or MOF application as the basal dressing at the 30~50% level of STNF and CF application as the additional dressing on the rest of STNF be best to maintain adequate nutrient of soil and to increase marketable yield for watermelon.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.506-513
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• 2010

Plant growth promoting ability of Methylobacterium oryzae CBMB20 was evaluated under different levels of organic fertilizer application on red pepper plants in a pot experiment. Oil cake as an organic N fertilizer was applied at the rates of 70, 85, 100 and 120% of the conventional recommended level. Each treatment was further treated with or without M. oryzae CBMB20 inoculation. The recommended amount of compost for red pepper was added in all the treatments. Results revealed that plant height, dry biomass and fruit yield were enhanced in increasing order as the rate of fertilization increased. Overall plant growth was improved due to the inoculation of M. oryzae CBMB20 and red pepper fruit yield was also increased by 10-35% in the plants inoculated with M. oryzae CBMB20 at different rates of organic fert1izer application. Total methylotrophic bacterial population in rhizosphere soil measured at the time of harvest was significantly higher in M. oryzae CBMB20 inoculated treatments. The growth promoting effect of M. oryzae CBMB20 found in red pepper could be due to the effective colonization of the bacteria in the rhizosphere and its ability of enhancing nutrient availability and producing plant growth hormones. With the plant growth promoting effect of M. oryzae CBMB20, the rate of organic fertilizer application can be reduced without any significant decreases in biomass production and yield of red pepper.

• Journal of Bio-Environment Control
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• v.6 no.2
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• pp.97-102
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• 1997

To investigate the effect of nitrogen level on the yield and quality of watermelon(Citrullus vulgaris S. cv. Bocksubak), N levels of 250, 200, 140, and 0kg/ha with the conventional amount of K and P supply non-fertilization treatments were compared one anther. Plant height, leaf area, fresh weight and dry weight were better in nitrogen application treatments than no nitrogen and non- fertilization treatments. But there was no significant difference between nitrogen levels. Yield and fruit setting ratio were the highest in N level of 140kg/ha. Fruit weight was increased by N application, and soluble solids content was the highest as 12.5 $^{\circ}$Bx in N level of 140kg/ha. Nitrogen content of leaves was increased with the applied nitrogen amount and highest at the middle stage of growth. P content was no significant difference between treatments. Ca content was increased with the applied nitrogen amount and highest at the late stage of growth.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.109-115
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• 2011

This study was carried out to investigate the plant growth of various ferns affected by the shading and fertilizer application and to recommend the appropriate levels of light intensity. Evergreen ferns like Dryopteris nipponensis Koidz., Cyrtomium falcatum (L. f.) Presl, Onychium japonicum (Thunb.) Kunze and deciduous ferns like Athyrium niponicum (Mett.) Hence, Thelypteris decursive-pinnata Ching, Athyrium brevifrons Kodama ex Nakai were used in this experiment. Evergreen ferns showed the best growth in the shading level of 30~60%. The plant growth and ornamental value (leaf color) of these plants were improved according to the fertilizer application in appropriate shading levels. The survival rate remained constantly in all treatments. Deciduous ferns showed the best growth in different shading levels from 0 to 60%. Some treatments showed improved growth according to fertilizer application, whereas survival rate was in the other treatments. There were differences in plant growth of evergreen and deciduous ferns according to fertilizer application, and additional researches must be executed to explain these reponses.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.5
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• pp.37-48
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• 2015

Soil nutrient management is important to maintain the constant productivity of seedling production in the nursery for successful forest restoration. This study investigated the effects of organic manure and chemical fertilizer application levels on the growth, soil properties, and nutrient concentrations of yellow poplar seedlings. One-year-old yellow poplar seedlings were treated with the combination of 3 level organic manures(0, 5 Mg/ha, 10 Mg/ha; mixture of poultry manure, cattle manure, swine manure, and sawdust) and 3 level nitrogen-phosphorus-potassium(NPK) chemical fertilizers(0, 1x(urea, $30g/m^2$; fused superphosphate, $70g/m^2$; potassium chloride, $15g/m^2$), 2x). Organic manure significantly increased the soil pH and the concentrations of nitrogen, available phosphorous, exchangeable potassium, calcium, and magnesium. In contrast, the NPK chemical fertilizer decreased the soil pH and exchangeable calcium concentration, did not affect the soil concentrations of nitrogen and magnesium, and increased the concentrations of available phosphorous and exchangeable potassium. Both organic manure and NPK chemical fertilizer treatments increased the seedling height, root collar diameter, and dry weight by 39% and 25%, respectively. The treatment with manure 5 Mg/ha and NPK 2x chemical fertilizer mostly increased seedling dry weight by 2.6 times more than that of the control. Compared to the effects of the fertilization treatments on the soil properties, the effects on nutrient concentrations in the leaves were relatively small. These findings indicate that organic manure that was derived from livestock byproducts and sawdust can be utilized with chemical fertilizer to improve seedling production as well as conserving soil quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.247-255
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• 2005

ice yield and plant growth response to nitrogen (N) fertilizer may vary within a field, probably due to spatially variable soil conditions. An experiment designed for studying the response of rice yield to different rates of N in combination with variable soil conditions was carried out at a field where spatial variation in soil properties, plant growth, and yield across the field was documented from our previous studies for two years. The field with area of 6,600 m2 was divided into six strips running east-west so that variable soil conditions could be included in each strip. Each strip was subjected to different N application level (six levels from 0 to 165kg/ha), and schematically divided into 12 grids $(10m \times10m\;for\;each\;grid)$ for sampling and measurement of plant growth and rice grain yield. Most of plant growth parameters and rice yield showed high variations even at the same N fertilizer level due to the spatially variable soil condition. However, the maximum plant growth and yield response to N fertilizer rate that was analyzed using boundary line analysis followed the Mitcherlich equation (negative exponential function), approaching a maximum value with increasing N fertilizer rate. Assuming the obtainable maximum rice yield is constrained by a limiting soil property, the following model to predict rice grain yield was obtained: $Y=10765{1-0.4704^*EXP(-0.0117^*FN)}^*MIN(I-{clay},\;I_{om},\;I_{cec},\;I_{TN},\; I_{Si})$ where FN is N fertilizer rate (kg/ha), I is index for subscripted soil properties, and MIN is an operator for selecting the minimum value. The observed and predicted yield was well fitted to 1:1 line (Y=X) with determination coefficient of 0.564. As this result was obtained in a very limited condition and did not explain the yield variability so high, this result may not be applied to practical N management. However, this approach has potential for quantifying the grain yield response to N fertilizer rate under variable soil conditions and formulating the site-specific N prescription for the management of spatial yield variability in a field if sufficient data set is acquired for boundary line analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.289-295
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• 2001

Experiments were conducted to find out the optimum level of slow release N fertilizers when total amounts of nitrogen required throughout the growing season in paddy were applied in the soil of seedling box. To evaluate the emergence rate and growth of rice seedlings, five levels of Meister (MS) 10, MS S10, and latex coated urea (LCU) which are equivalent to 0, 40, 60, 80, and 100kg N h $a^{-l}$ were mixed in soil of the seedling box. Emergence rate differed depending on the fertilizers and N levels; in MS 10 plots the emergence rate was 40.8% at 40kg N h $a^{-l}$ and no seedlings were emerged at the higher levels, in MS S10 plots higher than 80% at all the N levels, and decreased with the N levels from 70.0% at 40 kg N h $a^{-l}$ to 59.5% at 100kg N h $a^{-l}$ of LCU. Seedling started to wilt at 40 kg N h $a^{-l}$ of MS 10 and 80 and 100 kg N h $a^{-l}$ N of LCU on the 8th day after sowing, while seedling growth was normal at all the levels of MS S10. Field performance of rice was evaluated at the 0, 30, 60, 90, 120kg N h $a^{-l}$ of MS S10 applied in the soil of seedling box and N was not applied in paddy. Grain yield at 90 and 120kg N h $a^{-l}$ of MS S10 was similar to conventional urea split application (120 kg N h $a^{-l}$), but significantly higher compared to 30 and 60kg N h $a^{-l}$ of MS S10. Fertilizer N recovery decreased with N levels and the N recovery at 90 kg N h $a^{-l}$ of MS S10 and conventional urea split application were 62.2 % and 44.2%, respectively, with similar grain yield. The optimum level of MS S10 to be applied in seedling box seems to be about 90 kg N h $a^{-l}$ considering grain yield, price of fertilizer, labor applying fertilizer, and fertilizer N recovery.d fertilizer N recovery.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.269-273
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• 2005

A field experiment was conducted to evaluate the effect of slow-release fertilizer on the yield and quality of the third-harvest tea leaves. The yield of the third harvested tea leaves was decreased to 5.8-14.4% in slow-release fertilizer block, except to the N $50kg\;10a^{-1}$ ($316kg\;10a^{-1}$), compared to traditional urea treatment ($313kg\;10a^{-1}$). Nitrogen uptake and nitrogen uptake efficiency of slow-release fertilizer was reduced as nitrogen application level increased. The contents of chemical components related to the tea quality such as total-nitrogen, total amino acid, chlorophyll and theanine were somewhat lower in the slow-release fertilizer treatments, except to the treatment of N $50kg\;10a^{-1}$, than those in the traditional urea application, but those of tannin, caffeine and vitamin C were not different among the treatments. In scoring test, apparence and quality of green tea of the slow-release fertility treatments were not different, except to the N $40kg\;10a^{-1}$ treatment, compared to those in the treatment of urea. In conclusion, slow-release fertilizer and conventional urea treatments showed not different in both yield and quality of green tea.

• Korean Journal of Organic Agriculture
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• v.27 no.1
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• pp.87-100
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• 2019

The study was initiated to compare crop productivity as affected by a long-term application with homemade liquid fertilizers in leading organic cucumber (Cucumis sativus L.) farms in Suncheon and Kimcheon provinces. A Suncheon farm have applied an EM (effective organism) liquid fertilizer for one year and fifteen years, designating as EM 1-year and EM 15-year plots, respectively, with 4-year and 5-year application of native microbes-liquid fertilizer in Kimcheon farm, designating as Micro 4-year and Micro 5-year plots, respectively. pH in the EM-liquid fertilizer was high to approximately 7.7, and EC in the Micro-liquid fertilizer was 0.1 dS/m higher than those of EM-liquid fertilizer, with similar macro-nutrient concentrations observed in the both liquid fertilizers. Soil EC was the highest to the 10.0 dS/m for the liquid fertilizer with EM 1-year and showed less than 1.5 dS/m for other liquid fertilizer plots. Micro-liquid fertilizer plots had soil OM contents less than 20 g/kg, which was approximately two times less than those of EM plots. Soil microbial properties were not significantly different among the liquid fertilizer plots. SPAD and PS II values were significantly increased by EM 15-year plots with high levels of soil OM and EC. Liquid fertilizer plot with EM 1-year had high concentrations of T-N, Ca, and Na in the cucumber crops but low concentrations of P and Mg, in particular for low K of 1.2% which was two times less than those of desired level for an optimum cucumber growth. The lowest fruit yield was observed for the liquid fertilizer plot with EM 1-year with the highest soil EC accumulated. Liquid fertilizer plot with EM 15-year produced the expanded volume of crop canopy and increased fruit yield. Therefore, long-term of continuous application with an organic liquid fertilizer would have sustainably improved soil stability and the crop productivity.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.386-391
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• 1985

In sandy paddy soil, the occurrence of leaf and neck blast was investigated depending upon nitrogen fertilizer application level of 10, 15, 20kg per 10a and different application method of surface application, whole layer application and integrated improvement. An occurrence of leaf and neck blast was significantly increased with increasing nitrogen application up to. 20kg/10a. Also a close relation between leaf and neck blast was observed. Effect of fungicides on blast control was 62.5-93.5 percent compared to those of no fungicides. Yield of unhulled rice was 604kg/10a in plots of no fungicides, however, it was 719kg/10a in plots with fungicides. Yield loss was 15.6% in case of blast infection.