• Korean Journal of Soil Science and Fertilizer
• /
• v.20 no.2
• /
• pp.185-192
• /
• 1987

A green house experiment was conducted to find out the acetylene reducing and $N_2$-fixing activity from photosynthetic and aerobic heterotrophic nitrogen fixing microorganisms in submerged paddy soil under different agricultural locality, soil series, soil texture, soil type, and drainage condition in which samples taken from without nitrogen treatment plot of NPK trials on 16 sites of the farmer's field. The results obtained were summarized as follows: 1. The highest acetylene reducing activity was observed at 7 days after incubation in the light condition (photo synthetic microbes+heterotrophic bacteria) while it was observed at 35 days incubation in the dark condition (heterotrophic bacteria). 2. Among the soil series, photosynthetic nitrogen fixing activity was pronounced more in Jangae, Ogcheon and Hwadong series while lower was obtained in Buyong and Daejeong series. Aerobic heterotrophic nitrogen fixing activity was high in Buyong and Daejong series. 3. Estimated amount of $N_2$-fixation from acetylene reducing activity was equivalented to 3.0 mg in light condition and 4.9 mg/100g/105 days in dark condition. 4. Among the agricultural locality, photosynthetic nitrogen fixing activity was high in rather warm southern part while heterotrophic nitrogen fixing activity was predominated more in mountainous area and Chungcheong continental. 5. Photosynthetic nitrogen fixing activity was predominated in high productive soil while aerobic heterotrophic nitrogen fixing activity was pronounced more in crose coarse sandy soil. 6. The soils properties of high photosynthetic nitrogen fixing activity were constituted of poorly or imperfectly drained clay or clay loam soil while heterotrophic nitrogen fixing activity was pronounced more in well to moderately well drained sandy or sandy loam soil.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.579-584
• /
• 2013

The study was conducted to investigate changes in the characteristics of inorganic components during fermenting process of organic liquid fertilizers according to the type and ratio of microorganism and the amount of molasses when producing organic liquid fertilizers using sesame oil cake and rice bran. To select appropriate microorganisms, liquid fertilizers were produced through a 90-day fermentation process by adding mag-ggeo-li, yogurt, dried yeast, and leaf mold. The pH in liquid fertilizer was decreased, and then increased in all microorganism samples except the mag-ggeo-li sample. The EC was rapidly increased in all samples until the $10^{th}$ days after production, and showed no changes after the $60^{th}$ days in dried yeast and after the $30^{th}$ days in the other samples. The concentration of $NH_4$-N was generally increased with time. The concentration of $P_2O_5$ was rapidly increased until the $10^{th}$ days after production and was maintained at about 1% regardless of the type of microorganism. In terms of the characteristics of liquid fertilizers according to the ratio of selected dried yeast, the pH was decreased until the $30^{th}$ days after producing the liquid fertilizers, and then was increased regardless of the ratio of dried yeast. The EC was increased with time and showed no differences depending on the amount of dried yeast. The concentration of $NH_4$-N was increased with time and in proportion to the amount of dried yeast. In terms of the characteristics of liquid fertilizers according to the ratio of molasses, the pH was decreased with increasing the molasses. The EC and concentration of $P_2O_5$ were no differences according to the amount of molasses. When 3% molasses was added, the content of $NH_4$-N was 2.6 mg $L^{-1}$ at the beginning and was at 3,025 mg $L^{-1}$ on the $90^{th}$ days.

• Journal of Wetlands Research
• /
• v.26 no.2
• /
• pp.168-181
• /
• 2024

Constructed wetlands (CWs) deliver a range of ecosystem services, including the removal of contaminants, sequestration and storage of carbon, and enhancement of biodiversity. These services are facilitated through hydrological and ecological processes such as infiltration, adsorption, water retention, and evapotranspiration by plants and microorganisms. This study investigated the correlations between microbial populations, soil physicochemical properties, and treatment efficiency in a horizontal subsurface flow constructed wetland (HSSF CW) treating runoff from roads and parking lots. The methods employed included storm event monitoring, water quality analysis, soil sampling, soil quality parameter analysis, and microbial analysis. The facility achieved its highest pollutant removal efficiencies during the warm season (>15℃), with rates ranging from 33% to 74% for TSS, COD, TN, TP, and specific heavy metals including Fe, Zn, and Cd. Meanwhile, the highest removal efficiency was 35% for TOC during the cold season (≤15℃). These high removal rates can be attributed to sedimentation, adsorption, precipitation, plant uptake, and microbial transformations within the CW. Soil analysis revealed that the soil from HSSF CW had a soil organic carbon content 3.3 times higher than that of soil collected from a nearby landscape. Stoichiometric ratios of carbon (C), nitrogen (N), and phosphorus (P) in the inflow and outflow were recorded as C:N:P of 120:1.5:1 and 135.2:0.4:1, respectively, indicating an extremely low proportion of N and P compared to C, which may challenge microbial remediation efficiency. Additionally, microbial analyses indicated that the warm season was more conducive to microorganism growth, with higher abundance, richness, diversity, homogeneity, and evenness of the microbial community, as manifested in the biodiversity indices, compared to the cold season. Pollutants in stormwater runoff entering the HSSF CW fostered microbial growth, particularly for dominant phyla such as Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroidetes, which have shown moderate to strong correlations with specific soil properties and changes in influent-effluent concentrations of water quality parameters.

• Korean Journal of Agricultural Science
• /
• v.18 no.1
• /
• pp.74-79
• /
• 1991

In order to use of new organic matter source, soil samples collected from paddy, upland and orchard treated with kraft and paper board mill sludge were analysed comparing with non-treated soil in view of some soil properties, soil microorganisms and soil enzyme activities. Also, the value of fertilizer was estimated with kraft and paper board mill sludge. 1. Paper mill sludge showed more than 55% of organic matter content, and higher total nitrogen and phosphorus, and CEC. 2. Soils treated with kraft sludge were higher contents than non-treated 2.5-3 for organic matter, 1.5-2 for total-nitrogen, 2 for $NO_3$-N, 1.5 for phosphorus and 1.4 times for CEC. Also, 12-1.9 for bacteria and 3 times for fungi, and 1.4-1.5 of cellulase, 1.5-1.8 of phosphatase and 1.5-1.8 times of urease activities. 3. Organic matter contents, number of fungi, and activities of cellulase and phosphatase in soil treated with paper board sludge were 1.4-22, 2.4, 1.5-1.6 and 1.3-1.4 times higher than non-treated soil, respectively. 4. Paper mill sludge was evaluated as a good organic matter source to increase of soil organic matter, CEC, inorganic components, soil microbes and enzyme activities.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.2
• /
• pp.124-129
• /
• 1996

This experiment has been conducted to find out a effective decomposition method of popped rice hulls which are hard to be decomposed in vitro. It was found that the C/N ratio of 35 was better than the C/N ratio of 20 for improving the decomposition ratio of popped rice hulls. The addition of rice bran accelerated the decomposition of popped rice hulls. The real decomposition rate of popped rice hulls for 10 days was merely 8 percent. This poor decomposition ratio seemed to be come from the chemical constituent of rice hull which has 20 percent of silica content. It was considered that the addition of rice bran speeded up only the decomposition of bran itself by increasing the number of microorganisms. It was also observed that color changes developed from the decomposition of rice hulls proved not to be a yardstick for the degree of decomposition.

• The Korean Journal of Mycology
• /
• v.13 no.1
• /
• pp.41-47
• /
• 1985

Eighteen plant residues were added to soil and the amended soil was inoculated with chlamydospores (5,000 cells/g soil) of Fusarium solani causing root rot of ginseng in soil to test the effects of amendment using pea (Pisium sativa L.) as an index plant. Distributional conditions of microogranisms in soil were compared with each other before and after dealing with soil amendment by plant debries. Infection rate by index plant's infectivity showed a higher degree in the treatment of wheat crushed than in control group, and followed by stalk of sweet potato, chinese cabbage, ginseng leaves and soybean pod. On the other hand, the de­creasing order of infection rate was root of garlic, welsh onion, cabbage leaf and stalk, green onion stalk, wheat straw and barley straw. In comparison with control group, the propagules of fungi increased in the treatment of ginseng leaves, soybean ground, wheat crushed, maize stalk, and chinese cabbage, but decreased in the root of garlic, cabbage, and barley straw. Population of total bacteria increased in the treatment of soybean ground, chinese cabbage, radish stalk, welsh onion, and wheat crushed, but decreased in barley straw, tobaco root, ginseng stalk, and wheat straw. The numbers of actinomycetes increased only in the treatment of soybean ground in a comparison with control and also decreased in the garlic stalk and tobaco root. The propagules of Fusarium spp increased in the treatment of chinese cabbage, welsh onion, radish stalk, wheat crushed, and sweet potato stalk, wheat crushed, and sweet potato stalk, but decreased in the treat­ment of wheat straw, ginseng leaves, and cabbage than control.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.1
• /
• pp.52-60
• /
• 2000

This study was conducted to gain basic data for alleviation of gas emission and conservation of healthy soil environment by investigating an aspect of gas emission and microbial diversity due to the supplement of different fertilizers after application with a livestock manure compost in greenhouse soils. Green pepper was cultivated in clay loamy soil from April to August. Before planting, a livestock manure compost was applied with $741mg\;ha^{-1}$ on the basis of the phosphate content contained in compost. And then, deficient nitrogen for cropping was supplemented with either quick-acting fertilizer of urea or a controlled slow release fertilizer made from urea formaldehyde(U/F). $NH_3$ and R $NH_2$ gases emitted from soil showed a low concentration in the early stage but a maximum in 27 days after planting, then decreased rapidly and not detected after 33 days. Their average concentrations were 42% and 85% lower in the treatment of slow release fertilizer than that of urea fertilizer, respectively. $CO_2$ gas emitted under urea fertilization was ranged from 1,200 to $3,200mg{\ell}^{-1}$ and that in slow release fertilizer was $900{\sim}2,650mg\;{\ell}^{-1}$. The average concentration of urea treatment was $2,260mg{\ell}^{-1}$ and 30% higher than that of slow release fertilizer. The treatment of slow release fertilizer with the lapse of cropping time populated larger in numbers of bacteria, actinomycetes, nitrate bacteria and nitrate reduction bacteria, and ratios of bacteria and actinmycetes to fungi than that of urea fertilizer. But the number of fungi was higher in the treatment of urea fertilizer and denitrifying bacteria showed a similar trend in both treatments. The microbial diversity index, which calculated with numbers of 6 species of microorganisms, was decreased with increasing of growing stage in the range of 0.1 to 0.35 and that was higher in the tratment of slow release fertilizer than urea.

• Korean Chemical Engineering Research
• /
• v.46 no.4
• /
• pp.819-823
• /
• 2008

Microorganisms isolated from petroleum contaminated site were tested for their ability to grow on JP-8 by culturing them on the culture medium that contains JP-8 as a carbon source. The microorganism which grew on JP-8 containing minimal salt medium was separated and identified as Rhodococcus fascians. Changes in JP-8 biodegradation of R. fascians that was isolated from petroleum contaminated site was investigated with various inoculums sizes, JP-8 concentrations, medium pHs, and culture temperatures. The amount of JP-8 was analyzed by TPH using Gas Chromatography.

• Korean Journal of Environmental Agriculture
• /
• v.17 no.3
• /
• pp.254-259
• /
• 1998

This study was focused on finding out the potential problems associated with organic farming system. The effect of composted animal manures subsequent inoculation of microbes on growth and yield of tomatoes (Lycopersicon esculentum Mill. 'Minicarol') were examined to develop a proper organic farming practice. Plant heights were greater in composted manure treatment than in conventional practice, whereas widths of leaves were higher in conventional field. Chlorophyll contents between various amount of composted manure application were gradually decreased and showed no significant differences after 45 days of planting. The yield in the treatment applied 12 ton of composted animal manure per 10a as pre-planting fertilizer and following microbial inoculation were only 50-60% compared to that of conventional farming. However, yield increased up to 80% when additional composts were applied to the treatment received 6 ton of composted animal manure per 10a in the middle of cultivation. Microbial inoculation followed by composted manure application induced rapid decrease of nitrogen content in soil. However, the density of microorganisms was significantly increased. Tomatoes produced through organic farming were clear in color, Further, soluble solid and acid content were increased. The highest level of acid and solids were observed in the treatment applied 12 ton of digested swine manure per 10a. Although nitrogen content including ammonium and nitrate rapidly increased after application of composts, these were significantly reduced approximately 4-5 weeks after planting. The level of phosphorus, potassium, magnesium and calcium showed gradual decrease compared to nitrogen.

• Korean Journal of Soil Science and Fertilizer
• /
• v.17 no.1
• /
• pp.67-76
• /
• 1984

This experiment was conducted to find out the changes in microflora of submerged soil uncultivated rice plant by application of CNP herbicide (2, 4, 6 - Trichlorophenyl-4-Nitrophenyl ether) under conditions applied with compost, rice straw, glucose or without organic material. The soil, sandy loam textured was incubated in green house for 66 days. Sampling and analysis of microorganisms were carried out during submergence periods. The results were summarilized as follows. 1. Number of aerobic total bacteria was increased by application of CNP herbicide during submerbed 50 days, afterthen, could not seen the difference. The application of rice straw increased number of aerobic bacteria regardless of CNP herbicide application or not, but glucose tended to decrease. 2. Number of Fungi was constantly maintained at $8-20{\times}10^3$ levels during period of submergence regardless of application of CNP herbicide and organic materials or not. 3. The CNP herbicide application tended to decrease the number of actinomycetes, particularly, in the treatments without organic substances and rice straw were remarkably decreased. 4. Anaerobic-and gram-negative bacteria populations were not showed any difference by application of herbicide and organic materials. 5. The ratios of aerobic bacteria to fungi and aerobic bacteria to actinomycetes appeared high values by application of herbicide and of organic substances. 6. At 66 days after submergence, the ratio of chromogenic actinomycetes to the total number of actinomycetes was lowered in application of herbicide. On the other hand, the percentage of both pretense-positive and cellulase-positive actinomycetes to the total isolates were higher in the treatment with herbicide than An without herbicide, particularly. The ratios of pretense-positive actinomycetes were high in the rice straw application regardless of herbicide application or not, but cellulase-positive actinomycetes was not remarkably difference.