• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.417-425
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• 2011

This study was conducted to investigate the changes in physicochemical and microbiological properties during fermenting process of farm-made organic liquid fertilizer made of the mixture of organic materials such as blood meal and molasse during fermenting process. The pH level of organic liquid fertilizer during the ermentation decreased from 7.2 to 4.3. The EC of organic liquid fertilizer was increased from 13.9 dS/m to 99.3 dS/m during the fermentation. The total population of aerobic bacteria decreased from $8.2{\times}10^5$ cfu/ml to $3{\times}10^4$ cfu/ml, but Bacillus spp. increased from $2.1{\times}10^2$ cfu/ml to $4.2{\times}10^3$ cfu/ml during the fermentation. Bacterial isolates were obtained from organic liquid fertilizers and identified by fatty acid-base typing. The Genus Bacillus was dominant as fermenting proceeded. The denaturing gradient gel electrophoresis (DGGE) profile showed changes of bacterial communities in organic liquid fertilizers.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.4
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• pp.224-229
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• 2006

Utilization of organic by-product fertilizers has many beneficial effects on agricultural activities and in aspects of the disposal of enormous amounts of livestock manure. Most of these beneficial effects are related to the improvement of soil condition, such as fertility status and physicochemical quality of soil. But, appropriate indexes are needed to effectively manage the quality of organic by-product fertilizers amended on soil. To find chemical and physical standard to control the compost quality, the changes in chemical and physical characteristics of organic by-product fertilizers during composting were investigated, and also an appropriate physical method for this end. The results showed chemical properties, such as humic acid content, OM/N ratio, cation exchange capacity and salt content, had significant relationships during the composting. The water content, particle and bulk densities, particle size and color indices, as physical properties, were also applicable factors for the quality control of compost.

• Journal of Environmental Impact Assessment
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• v.23 no.2
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• pp.75-87
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• 2014

In order to analyze environmental impact of livestock manure and organic fertilizers, this study investigated livestock-breeding and pollution loads, the status of individual and public livestock manure treatment facilities, and the status of production, supply and components of compost and liquid fertilizers in the Nonsan area. Also, on a trial basis, this study investigated the life cycle of the environmental impact of livestock manure and its organic fertilizers on stream, groundwater, and agricultural soil. The results are as follows. Firstly, were detected the range of $0.13{\sim}1.32{\mu}g/L$ of As, $0.004{\sim}0.467{\mu}g/L$ of Cd and $0.5{\sim}9.2{\mu}g/L$ of Pb as a harmful substances which show lower concentrations than person preservation criteria of water qualities and aquatic ecosystem. However, it is not clear that heavy metals affect environment such as stream, groundwater and agricultural soil. Secondly, this influence could change according to investigation time and treatment efficiency. As were detected large amounts of persistent organic pollutants(e.g. $14.24{\sim}38.47{\mu}g/L$ of acetylsalicylic acid, $1.17{\sim}2.96{\mu}g/L$ of sulfamethazine, and $2.25{\sim}174.09{\mu}g/L$ of sulfathiazole) in effluent from livestock farms and small amounts of sulfathiazole($ND{\sim}1.63{\mu}g/L$) in the stream, it is necessary to monitor POPs at individual and public livestock manure treatment facilities. However, significant environmental impact did not appear at groundwater and agricultural soil in the test area supplied with liquid fertilizers. These results could be applied to investigate the environmental impact of livestock manure through a comprehensive livestock manure management information system.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.44-52
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• 1996

Humic substances of 17 organic fertilizers available on the market were the objects of study. The list of ingredients for formulation of them comprised fish meal. bone meal, oil-cakes, brewer's grains, peat, sawdust, wood bark, zeolite, soil conditioner, live-stock droppings, amino acid fermentation byproduct, chaff, limestone and others. Humic and fulvic acids were isolated from those substances and given chemical and spectroscopic analyses. Nutritional values of the organic fertilizers showed big diversity. Humification of organic matter was incomplete for some of the fertilizers as indicated by a high C/N ratio. Extractable humic acid percentage was higher, in general, than that of fulvic acid. Also the relative content of humin increased with advanced humification. Total acidity was closely related to phenolic hydroxyl groups. Relationships between carboxyl and hydroxyl groups. and carboxyl and alcoholic hydroxyl groups were very significant. Ultraviolet and visible light absorption spectra of humic and fulvic acids were substantially similar. The types of humic acids were B. P, and Rp. Two humic acids of the 17 samples belonged to B type. 3 to P type and all the rest to Rp type.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.67-71
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• 2012

Organic fertilizers are divided into natural organic and synthetic organics. The benefits of natural organic fertilizer were reported from the previous researches. The previous researches have reported that clippings are nitrogen source for turfgrass growth. However, the limited research results about clippings as a source of natural organic fertilizers were reported. The objective of the research to investigate effects of liquid fertilizer produced from fermented clippings for creeping bentgrass growth. Liquid fertilizer (LF) produced was used for the research to be compared with urea and two natural organic fertilizers of different source (NO-1 and NO-2). Kentucky bluegrass (Poa pratensis L., Midnight) was used for the study. Turfgrass quality was measured by visual evaluation every two weeks from June to October, 2011 using a scale of 1 to 9 (1=worst, 6=acceptable, and 9=best). LF produced greater turfgrass quality than acceptable quality, especially with the summer period while urea and NO produced lower turfgrass quality than acceptable quality of 6. LF had less quality alteration than urea and NO during the study. Based on the result of the study, LF are more stable to maintain turfgrass quality than urea and NO.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.202-207
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• 2011

Organic fertilizers are divided into natural organic and synthetic organics. The benefits of natural organic fertilizer were reported from the previous researches. However, the limited research results about clippings as a source of natural organic fertilizers were reported. The objective of the research to investigate effects of liquid fertilizer produced from fermented clippings for creeping bentgrass growth. Liquid fertilizer (LF) produced was used for the research to be compared with Urea and two natural organic fertilizers of different source (NO-1 and NO-2). Creeping bentgrass (Agrostis stolonifera L., L-93) was used for the study. Turfgrass quality was measured by visual evaluation every two weeks from June to October, 2011 using a scale of 1 to 9 (1=worst, 6=acceptable, and 9=best). Turfgrass disease damage was measured by percent of area damaged when a turfgrass disease occurred. LF produced lower damage than NO and urea when temperature was high. Although NO-2 produced the highest or equal to the highest turfgrass quality in June and October, LF had the highest or equal to the highest quality from July to September.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.290-303
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• 2003

Modern agriculture has been heavily dependent on chemical fertilizers to meet the food demands of ever increasing population. Progressive depletion of major plant nutrients in soil due to intensive cultivation practices has also necessitated the use of higher dose of chemical fertilizers particularly in soils where the organic matter content is very low. Indiscriminate use of chemical fertilizers and pressure on agriculturists to enhance per area crop yields has led to fast depletion of fossil fuel resources with concomitant increase in the prices of chemical fertilizers and also led to environmental pollution. Hence, the current trend throughout the world is to explore the possibility of using alternate nutrient sources or increasing the efficiency of chemical fertilizers by supplementing them with organic fertilizers and bioinoculants comprising largely microbes like, bacteria, fungi, algae etc to enhance nitrogen and phosphates in the soil thus creating a sustainable agricultural environment. Among the different microbial inoculants or biofertilizers, Azospirillum could be a potential candidate due to its non specific host root colonization. It had the capability to fix $N_2$ in wide pH regimes and even in presence of combined nitrogen. Azospirillum inoculation can increase the crop yield to 10-25% and substitute 25% of recommended doses of nitrogenous fertilizers. Apart from nitrogen fixation, Azospirillum is also involved in the root improvement, the activity which was attributed to an increase in the rate of water and mineral uptake by roots. The ability of Azospirillum to produce phytohormones was reported to enhance the root respiration rate, metabolism and root proliferation. They have also been reported to produce polyhydroxybutyrate, that can be used as a biodegradable thermosplastic. A lot of studies have addressed improvements in enhancing its efficiency to fix nitrogen fixation and hormone production.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.245-255
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• 2010

The study was conducted to investigate the effects of organic fertilizers and mulches on the growth and $CO_2$ assimilation in MM.106 apple trees. Growth and $CO_2$ assimilation of MM.106 apple trees grown in a greenhouse were affected by the nutrient concentrations and carbon (C) and nitrogen (N) ratio in the raw materials of organic fertilizers and mulches. The optimum C:N ratios, which makes microorganism convert the organic N into the inorganic N, were obtained in the organic fertilizer, poultry litter, green compost, and grass clippings, resulting in increasing single shoot height, SPAD, and $CO_2$ assimilation. The SPAD and $CO_2$ assimilation were affected by the treatments 5 weeks after the treatments, and then the tree growth was affected by the treatments 6 weeks later. The most efficient tree growth and development were observed in the 10 to $15\;mg{\cdot}kg^{-1}$ of the inorganic N in a soil, and the N was strongly related to the tree growth and development.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.81-87
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• 1979

In order to observe the lasting effect of NK-compound mineral fertilizer and organic compound fertilizer including Myweon organic liquid fertilizer, a pot experiment was conducted with rice (Oriza Sativa) variety: Nong Back. These fertilizers were applied as basal and the same amount of urea form of nitrogen was top dressed about a month after transplanting, July seventh, 1977. Results obtained are as follows; 1. The lasting effect of various fertilizers were laid in following decreasing order; Myweon liquid < Organic compound fertilizer (Myweon coop. made) > NK-compound fertilizer (Chosun coop. made) Single fertilizer. It was considered that organic matter served as microbial feed and lead a temporary fixation of available plant nutrients in the soil, and the reduced surface area of the compound fertilizers slowed down the availability of the fertilizers. 2. The fertilizer showing greater lasting effect produced more panicles per hill and less grains per panicle than the fertilizers showing less lasting effect, and brought low maturity, which resulted in low paddy yield the paddy producing efficiency of nitrogen absorbed by straw was also low in the former fertilizers. Such advanced effect of the former fertilizer was considered to be related with the variety of early maturity and unseasonable topdressing of fertilizer which made at the maximum tillering stage. 3. For the production of Japonica type paddy with heavy fertilization which may required to depress the early growth a little and promote the late growth, it might be necessary to develop slow releasing fertilizers such as single fertilizer formulated to a large grains or compound fertilizer containing organic matter. 4. If the nitrogen content of paddy, Nong Back, far excess 0.64 or 0.65% and reaches 0.68% or above, the yield of the variety seemed to be decreased remarkbly through the low maturity rate and thousand grain weight.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.867-873
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• 2015

The potential of nitrogen mineralization was studied by applying organic fertilizer to soil and incubating at $25^{\circ}C$ for 28 weeks. The organic fertilizers used in this experiment were oil-cake (CF-I, CF-II) and amino acid fertilizer (AAF-I, AAF-II). Accumulated mineralized nitrogen (N) fits the frist-order kinetics during incubation. The N mineralization potential ($N_0$) for organic fertilizers treated soil was highest at AAF-II treatment with a value of 27.71 N mg/100g, then followed by CF-II, AAF-I, CF-I. The pure N mineralization potential ($N_0$ treatment - $N_0$ control) for CF-I, CF-II, AAF-I, AAF-II were 2.55, 5.83, 3.66, 8.57 N mg/100g, respectively. The amount of N mineralized from organic fertilizers applied soil ranged from 46% to 61% of the total N content in organic fertilizer. The half-life ($t_{1/2}$) of organic nitrogen in soil treated with oil-cake and amino acid fertilizer was 17-21 days. Therefore, half of nitrogen contained in oil-cake and amino acid fertilizer was mineralized after 3 weeks application.