• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.328-335
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• 2010

This study was conducted to determine effects of soil pH and form of nitrogen fertilizers on tomato growth and chemical properties of greenhouse soil using ferigation system. Tomato (Lycopersicon esculentum Mill. cv. Superdoterang) were grown for three months in 18 L pots filled with two soil (pH 6.8 and pH 8.7). 4 different nitrogen fertilizers (urea, ammonium nitrate, ammonium sulfate, and potassium nitrate) were fertigated with different concentrations of 0, 10, 50, and 100 mg N/L during tomato cultivation. Soil pH 8.7 decreased yield and chlorophyll fluorescence compared with soil pH 6.8. Yield at soil pH 8.7 increased by ammonium nitrate and ammonium sulfate fertigation. Soil pH 6.8 induced increment of yield by nitrogen concentration than form of nitrogen fertilizers. Soil pH after cultivation of tomato decreased by application of ammonium nitrate and ammonium sulfate. Soil EC by 100 mg N/L application of ammonium sulfate was twice as much as other fertilizers. Form of nitrogen fertilizer had less effect on concentration of soil $NH_4^+$-N and $NO_3^-$-N in soil but the concentrations slightly reduced at pH 8.7. These results indicate that application of urea and ammonium nitrate for a nitrogen source of fertigation has little affects on soil chemical properties before and after tomato cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.463-471
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• 2000

A pot experiment was carried out to find out the effects of the sludge application on corn and Chinese cabbage growth and changes in soil chemical properties with sludges collected from 4 plants at 0, 12.5, 25, 50, and $100Mg\;ha^{-1}$ levels and chemical fertilizer. With the corn experiment, the pot where sludge and chemical fertilizers were treated together, greater amount of sludge resulted in initial growth inhibition. In general, higher sludge treatment rates resulted in better growth in the end, whereas initial growth was inhibited due to high the electrical conductivity of saturated extracts(ECe) for the Chinese cabbage. However, the highest yield among sludge treatments was lower than the yield with chemical fertilizers. While the treatments resulted in chemical changes in soil showing differences of cation exchange capacity, organic matter contents, and nitrogen contents, hardly any changes were detected before and after crops were grown. Inorganic nutrients such as Na, K, Ca and Mg showed similar changes. The ECe in soil saturation extract decreased after crops were grown. The more sludge was treated, the greater was the decrease. The differences of ECe in the soil saturation extract with varying degrees of treatment were also reduced after crops were grown. Available phosphorus content increased during growth. Due to the low nitrogen content in sludge, when nitrogen becomes the determining factor for the amount of sludge treatment, phosphorus buildup resulted from continued application of sludge could be raised. Therefore, it is advisable to use phosphorus, not nitrogen content, in determining the amount of sludge treatment and chemical fertilizer as supplementary sources for nitrogen.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.420-426
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• 1998

This investigation was undertaken to clarify the effects of application of chemical fertilizers (Compound fertilizer and commercial compost) and organic matters (straw and clover) on changes of the composition of soil actinomycetes flora. Actinomycetes were isolated from chemical fertilizer and organic materials treated soils, and then grown on HV agar plate. The isolated strains were classified by Bergey's manual based on the morphological characteristics and color of substrate mycelium of actinomycetes. The number of actinomycetes increased 4 times in control, 36 times in clover, 20 times in straw, 5 times in chemical fertilizer and 4 times in commercial compost treated soil after 14th day of incubation. This result suggests that the application of straw or clover is more effective to increase the number of actinomycetes than compound fertilizer or commercial compost. It also showed that the application of chemical fertilizer or organic materials considerably changed the composition of soil actinomycetes flora. The proportion of streptomyces strains to the isolated total actinomycetes was 62% in control, 60% in clover, 68% in straw, 67% in chemical fertilizer and 64% in commercial compost treated soils at the 14th day.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.805-819
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• 2017

The study was carried out to develop a mathematical model for evaluating the effect of organic fertilizers in organic rice production systems. A function to simulate the nitrogen mineralization process in the paddy soil has been developed and integrated into ORYZA2000 crop growth model. Inorganic nitrogen in the soil was estimated by single exponential models, given temperature and C:N ratio of organic amendments. Data collected from the two-year field experiment were used to evaluate the performance of the model. The revised version of ORYZA2000 provided reasonable estimates of key variables for nitrogen dynamics and crop growth in the organic rice production systems. Coefficient of determination between the measured value and simulated value were 0.6613, 0.8938, and 0.8092, respectively for soil inorganic nitrogen, total dry matter production, and rice yield. This means that the model could be used to quantify nitrogen supplying capacity of organic fertilizers relative to chemical fertilizer. Nitrogen dynamics and rice growth simulated by the model would be useful information to make decision for organic fertilization in organic rice production systems.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.9-13
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• 1986

An experiment on strawberry (Fragaria Grandflora EHRH) was conducted in order to compare the effect of two compound fertilizers made for this crop, by Kyonggi Chemical Crop. LTD. with that of muriate of potash, sulfate of potash and ammonium nitrate in a farmer's vinylhouse during the winter period of 1984 to 1985. Results obtained are as follows; 1. The effect of compound fertilizers on the growth, number of inflorescences and yield of strawberry showed no significant difference from the effect of muriate of potash, sulfate of potash and ammonium nitrate. But the former increased the content of reduced, and total sugars soluble in diluted acid in the juice of strawberry. 2. As a whole, sulfate of potash increased sugar content in strawberry juice more than muriate of potash, which became the reason to increase the sugar content in the strawberry juice harvested from the compound fertilizer plots.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.128-135
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• 2013

The use of agricultural by-products as alternative nutrient sources in crop production had gained popularity in order to reducing the rate of chemical fertilizer application in the field. This study was conducted to determine whether the application of rice milling by-products treated with yeast inoculants could substitute, or reduce the rate of chemical fertilizer application. The results of agronomic measurements showed that the effect of incorporated materials was not immediate, as compared to 100% chemical fertilizer application. However, grain yield and quality was either the same or greater than 100% chemical fertilizer application. It was found out that expanded rice hull (treated with yeast or not) could reduce the rate of applying chemical fertilizers by half. Also, yeast treatment was only favorable only to expanded rice hull and not with rice bran, and was already found to be a potential material in reducing chemical fertilizer application in rice production.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.487-493
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• 2013

The effects of long-term fertilization on soil biological properties and microbial community structure in the plough layer in a rice paddy soil in southern Korea were investigated in relation to the continuous application of chemical fertilizers (NPK), straw based compost (Compost), combination these two (NPK + Compost) for last 40 years. No fertilization plot (Control) was installed for comparison. Though fertilization significantly improved rice productivity over control, the long-term fertilization of NPK and compost combination was more effective on increasing rice productivity and soil nutrient status than single application of compost or chemical fertilizer. All fertilization treatments had shown significant improvement in soil microbial properties, however, continuous compost fertilization markedly increased soil enzyme and microbial activities as compared to sole chemical fertilization. Results of microbial community structure, evaluated by EL-FAME (ester-linked fatty acid methyl esters) method, revealed big difference among Control, NPK, and Compost. However, both Compost and Compost+NPK treatments belonged to the same cluster after statistical analysis. The combined application of chemical fertilizer and organic amendments could be more rational strategy to improve soil nutrient status and promote soil microbial communities than the single chemical fertilizer or compost application.

• Korean Journal of Organic Agriculture
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• v.14 no.1
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• pp.69-83
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• 2006

This experiment was conducted to investigate effects of application of diluted and undiluted cattle slurry with water on seasonal and annual dry matter yields and feed values of tall fescue in the uncultivated rice paddy and it was compared with chemical fertilizer. Annual dry matter yields for diluted (average 6.43 ton DM/ha) and undiluted (average 6.56 ton DM/ha) cattle slurry were significantly higher (p<0.05) than those of no fertilizer (3.82 ton DM/ha). This trend was much more conspicuous in treatments applied in spring. In chemical fertilizer treatments, fertilizers with P and K (6.12 ton DM/ha), and P, K and N (10.13 ton DM/ha) had significantly (p<0.05) higher dry matter yields compared with no fertilizer. However, annual dry matter yields for treatments of P and K mixture tended to be lower than those of cattle slurry applications. The efficiency of DM production for inorganic nitrogen in chemical fertilizers annually averaged 26.7kg DM/kg N. In terms of cutting frequencies, it was highest in 2nd growth followed by 1st and 3rd growth. On the other hand, efficiencies of annual DM production of nitrogen for diluted and undiluted cattle slurry were 18.3 and 17.4 kg DM/kg N, respectively, especially, highest in 2nd growth. While, efficiencies of DM production for cattle slurry versus for inorganic nitrogen were 68.5 (undiluted) and 65.2% (diluted), respectively. For annual crude protein contents of tall fescue, no fertilization (11.5%) was significantly higher than chemical fertilizer, but that was lower than cattle slurry ($12.4{\sim}12.6%$) diluted with water. on the contrary, no fertilizers had significantly lower NDF (64.1%) and ADF (37.2%) contents than those of any other treatments, but their RFV (87.0) was significantly higher (p<0.05) than other treatments. The application of cattle slurry and their dilution significantly increased yields of crude protein and total digestible nutrients compared with no and/or P and K fertilizers (p<0.05). This trend was more conspicuous in cattle slurry applied in the early spring.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.3
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• pp.41-48
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• 2021

This study aimed to develop an alternative organic fertilizer to castor oil cake-based fertilizers. To assess the nutrient effect of the developed fermented mixed organic fertilizers, the yield of lettuce and soil characteristics after growth were analyzed and compared to those of a trial using a mixed expeller cake fertilizer. Two fermented mixed organic fertilizers, FA and FB, each containing 5.0% nitrogen, 2.6% phosphate, and 1.4% potassium, were produced by mixing different ratios of rice bran, dried distillers grains, sesame oil meal, and fish meal. This study was conducted with six trials: untreated, mixed expeller cake fertilizer, and the fermented mixed organic fertilizers FA and FB. Based on the amount of nitrogen fertilization (70 kg ha^-1) on the lettuce, the fermented mixed organic fertilizers FA and FB were applied at 100% and 150%, respectively, and the mixed oil cake was applied at 100%. As the amount of treatment increased, there was no significant difference except the number of leaves in FA treatment. The yields from the FA100 and FB100 treatments were 38.2 and 40.8 Mg ha^-1, respectively, which was not significantly different from that of the mixed expeller cake fertilizer treatment at 38.3 Mg ha^-1. In addition, the nitrogen uptake and utilization efficiency of the lettuce were not significantly different between mixed expeller cake fertilizer and fermented mixed organic fertilizer treatments. Analysis of the chemical properties of the soil after the trial showed that he mixed expeller cake fertilizer treatment showed the lowest pH. There were no significant differences in electrical conductivity, content of soil organic matter, available phosphate, and exchangeable cation among the fertilizer treatments. However, the bacterial and actinomyces density was higher in the soil from the fertilizer trials than in the non-fertilizer trials. These results indicated that the two tested fermented mixed organic fertilizers had nourishing effects and soil characteristics that were similar to those of the mixed expeller cake fertilizer. Thus, farmers can use these fermented mixed organic fertilizers as alternatives to castor oil cakes for the cultivation of organic lettuce.

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.74-80
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• 1993

Survey on the status of cultivation and production of medicinal crop was studied on 18 medicinal herbs and 5 medicinal trees in 66 major crop producing complexes. Native seeds or seedlings of the crops obtained from self-seed or neighbored farmer were cultivated and organic fertilizer was preferred to chemical fertilizer in the complexes. More than 60.7% of farmers were applied compost among the organic fertilizers, while 34.8% of them cultivated without any organic fertilizers. Both of using the compound chemical fertilizers and urea and urea only used were showed 51. 5% and 40.9%, respectively. Ostericum koreanum, Angelica gigas, Phellopterus littoralis, and Bupleurum fulcatum belonging to the family Umbeliferae and Aralia continentalis, Polygonatum sibiricum and Eucommia ulmoides in the complexex were not damaged by insect pests and plant diseases. Mite, aphid, grub, cutworm, onion magot fly and european corn borer were known to as major insect pests and anthracnose, powdery mildew, brown leaf spot, leaf blight and root rot as major plant diseases. Productivity and income of a farm by medicinal crops in the complex were greatly different from seeding time, planting distance, year yielded, and selling routes even in the same cultivation method and in the same cultivated area.