• 한국환경농학회지
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• 제27권2호
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• pp.163-170
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• 2008

유기물이 많고 작물생육이 양호한 시설 및 논토양에서 우점하는 광합성 세균을 분리하여 대두박 등의 유기물질과 혼합하여 혼합유기질 비료를 개발하였고 상추에 대한 시용효과를 검토하였다. 광합성 세균은 시설 및 논토양에서 형태적으로 가장 분포도가 많은 균주를 선정하고 이를 SA16 균주로 명명하였다. 선발된 균주는 폭 $0.5{\sim}1.2{\mu}m$, 길이 $2{\sim}2.5{\mu}m$의 간균 혹은 구균에 가까운 형태로 관찰되었으며 16S rDNA 분석으로 1.3 kb DNA 단편을 얻어 염기서열을 분석한 결과 Rhodobacter sp.와 가장 유사한 것으로 나타났다. 질소기준으로 토양 검정시비 처리구와 동량인 혼합유기질비료 0.90 Mg $ha^{-1}$ 처리구는 대조구 보다 주당 엽수는 2장 정도 많았고 뿌리길이도 2 cm 정도 길었다. 혼합유기질 비료 시용량별 수확량은 $0.90{\geqq}0.45>1.35Mg\;ha^{-1}$ 순으로 많았으며 5% 수준에서 처리간에 유의성이 인정되었고 최대 수확량을 얻을 수 있는 적정 시용량을 2차 회귀곡선($y=-0.0008x^2+0.1174x+21.332,\;R^2=0.9951$)으로 구한 결과 0.72 Mg $ha^{-1}$로 나타났다. 수확 후 토양 공극율은 혼합유기질 비료1.35 Mg $ha^{-1}$ 처리구가 58.8%로 가장 좋은 것으로 나타났으며 혼합유기질 비료 처리에 따른 토양중 호기성세균의 분포는 혼합유기질 비료 0.90 및 1.35 Mg $ha^{-1}$ 처리구가 12.4, 및 $12.8{\times}10^6CFU\;g^{-1}$로 가장 높았다.

• 한국토양비료학회지
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• 제49권5호
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• pp.531-540
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• 2016

The adoption of legume cover crops in no-tillage system can contribute to improve soil fertility by providing several benefits, including reduction in soil erosion, suppression of weed growth and N supply to subsequent crops. We conducted a field study to investigate the effect of cover crops and nitrogen fertilization rates on yield and nitrogen use efficiency of waxy corn (Zea mays L.) in no-tillage upland field. Two legume cover crops, hairy vetch (Vicia villosa Roth) and crimson clover (Trifolium incarnuturn L.) were mechanically terminated with roller in early June. For each cover crop treatment, nitrogen (N) fertilizer was applied at three different rates (145, 72.5 and $0kg\;N\;ha^{-1}$). The growth and yield characteristics of corn were significantly affected by the N fertilization rates in crimson clover plots, which suggest N mineralization from the cover crop residue was not sufficient. In contrast, N fertilization rates had no significant effect on growth and yield of corn in hairy vetch plots, indicating that the amount of N released from the cover crop is large enough to meet most of the N requirement of corn. However, the application of N fertilizer in hairy vetch cover plots resulted in slight increase of crop yield, though not statically significant, and high levels of N concentration in corn plant tissue possibly due to luxury consumption of N. Organic residues on the soil surface in hairy vetch cover plots had substantial amounts of N after harvest, ranging from 100 to $116kg\;N\;ha^{-1}$, which is presumably retained during winter season and released by microbial mineralization in subsequent year. The highest nitrogen yield efficiency was achieved in the plot with hairy vetch cover and no N fertilizer application, followed by the plot with hairy vetch cover and $72.5kg\;N\;ha^{-1}$ fertilization rate. In conclusion, hairy vetch showed better performance in corn productivity as compared with crimson clover. In addition, it was concluded that the application of N fertilizer between 0 and $72.5kg\;N\;ha^{-1}$ in combination with hairy vetch cover crop might be most efficient for corn yield under no-tillage system with climatic and soil characteristics similar to those of the experimental site.

• 한국토양비료학회지
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• 제43권5호
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• pp.650-658
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• 2010

시설재배지의 경우 휴작기간 동안 녹비작물의 활용가능성이 높을 것으로 판단된다. 본 연구는 녹비작물이 시설재배지에서의 양분공급 및 토양질 개선에 미치는 영향을 평가하고자 두과 (헤어리베치, 크림손클로버) 및 화본과 (호밀, 수수, 수단그라스) 녹비작물을 재배 후 토양과 혼합하였으며, 무기질소 공급능과 생물적 지표로써 토양 탄수화물, 미생물활성 및 부식함량의 경시적 변화를 측정하였다. 관행구의 무기태 질소함량은 전 기간 비슷한 수준을 유지하였으나 녹비작물을 처리한 토양에서는 토양처리 후 4주까지 무기태질소 함량이 지속적으로 증가하였고, 특히 수단그라스에서 무기태질소 함량이 두드러지게 증가하였다. 녹비작물 처리 후 토양 중 수용성 당은 두과 녹비작물 처리 후 서서히 증가하기 시작하여 7주 경에 가장 높았으며 이후 서서히 감소하는 경향이 나타났다. 반면 화본과 녹비작물 처리 후 수용성 당이 빠르게 증가하여 처리 후 4주 경에 최대치에 도달한 후 감소하는 양상이 나타났다. 토양 내의 부식산 (humicacid)은 아무것도 첨가하지 않은 관행구와 녹비처리 초기에는 비슷한 수준으로 낮았으나 녹비처리 후 4주 정도 시간이 경과하면서 녹비작물의 부숙에 의해 형성된 부식산이 점점 증가하는 것을 확인할 수 있었다. 또한 양이온과 결합하여 물에 잘 용해되는 염을 만드는 fulvic 산에서도 작물 간 차이는 있었지만 부식산의 함량 변화와 비슷한 경향이었다.

• 한국토양비료학회지
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• 제47권6호
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• pp.500-505
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• 2014

In recent years, organic ginseng cultivation has increased because customers prefer organic ginseng products due to the morphological quality as well as the safety such as the residuals of chemically-synthesized pesticides. Therefore, some of paddy and upland fields were converted into organic ginseng fields. Soil chemical properties, soil microflora, and soil-inhabiting animals were investigated in paddy-converted and upland organic ginseng fields in Sangju city, Korea. There was few difference in the soil chemical properties, and the soil nutrient concentrations, such as nitrate-N, Av. $P_2O_5$ between the two field types, and exchangeable cations such as K and Ca were within the ranges which are recommended by the standard ginseng-farming manual. Changes in microflora were also assessed by analyzing phospholipid fatty acid composition. Overall, indicators of microbial groups were greater in the upland field than in the paddy-converted soil, but they were not significantly different. In addition, there was no significant change in the abundance of nematodes, collembolans, and mites between the two field types probably because of the high variation within the field types. In this study, it was suggested that soil chemical and biological properties for organic ginseng cultivation were greatly influenced by the variation of topography and soil management practices rather than field types. Further study may be needed to investigate the influence of these factors on soil chemical and biological properties in organic ginseng soils.

• 한국토양비료학회지
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• 제45권4호
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• pp.551-554
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• 2012

The present laboratory investigation was conducted to assess the effect of heavy metals on carbon mineralization. Soil was treated with three concentrations (50, 100 and $150{\mu}mol\;g^{-1}$ soil) of two heavy metals (Cd and Zn) in a factorial combination of treatments replicated four times. Determination of carbon mineralization was carried out at 3, 7, 14, 21, 28, 42 and 56 days after metal treatments.. The amount of $CO_2$-C released from heavy metal treated soils was found to be decreased at an increasing rate during the first 28 days, followed by slow release as incubation progressed. The total amounts of $CO_2$-C released were 448, 382 and $348mg\;kg^{-1}$ soil respectively for soils treated with 50, 100 and $150{\mu}mol\;g^{-1}$ soil of Zn. The corresponding figures for Cd treated soils were 406, 354 and $282mg\;kg^{-1}$ soil implying that dose-dependent reduction in cumulative $CO_2$-C released from soils. The inhibition of carbon mineralization was found to be high in Cd treated soils than that of Zn treated. Therefore, tolerance and adaptation of the microbial community is likely to be related to the concentration and the type of metal. According to the results, carbon mineralization can be considered as possible indicator of soil pollution by means of heavy metals.

• 한국토양비료학회지
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• 제46권3호
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• pp.143-152
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• 2013

No-till farming system has been extensively studied all over the world as the effective method for maintaining the soil fertility. The general advantages of this system have been well known for reducing the labor, fuel, machinery, and irrigation cost as well as for increasing the soil quality through soil aggregation, water infiltration, microbial population and etc. Recently, it becomes more popular with the increase of interest on sustainable agriculture, especially because of its higher carbon sequestration potential compared to conventional tillage. Crop residue management should be essentially included to look forward to achieving the positive effect on reduction of greenhouse gas. Nonetheless, there are also negative opinions on effect of no-till farming system. For example, some researchers reported that soil physical properties were not improved by no-till under certain soil and climatic conditions. This means no-till farming systems were strongly affected by the soil characters and climatic conditions. Therefore, the researches to meet the specific-regional characters are greatly needed in order for no-till farming system to successfully settle in Korea. The objective of the review article is to present the future direction and perspective on no-till farming system in Korea. For this purpose, we summarized the results of domestic and foreign researches about no-till farming system until now. Specifically, the chapter on foreign research consisted of four parts: positive and negative effects, the effect in paddy soil, and latest research direction (2012-2013) of no-till farming systems. Whereas, review for domestic researches was divided into two main parts: paddy and upland soils. In the final chapter, the priorities for the optimum conservation tillage in Korea were discussed and proposed through the previous researches.

• Journal of Applied Biological Chemistry
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• 제48권1호
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• pp.11-15
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• 2005

Salinity of soils in greenhouse has been increased by massive application of fertilizers. Nitrogen fertilizer was most popular, and thus nitrate became the majority of soil salinity. Accumulation of nitrate led to deleterious effects on the growth and development of crops and vegetables. Microbial strains able to utilize nitrate and thus remove excess nitrate from farm land soils were isolated from 15 different soils of greenhouses and plastic film houses. Four strains able to grow in medium containing 50 mM $KNO_3$ were isolated, among which only E0461 showed high capacity of nitrate uptake. Nitrate uptake by E0461 was dependent on culture medium and was increased by addition of tryptone and peptone. Although E0461 was able to grow without tryptone and peptone, growth was slow, and no nitrate uptake was observed. Nitrate appeared to facilitate E0461 growth in the presence of tryptone and peptone. Through kinetic analysis, nitrate uptake was measured at various concentrations of nitrate, and half-life was calculated. Nitrate concentration decreased with increasing incubation period, and plot between half-lives and initial concentrations of nitrate fitted to single exponential function. These results suggest one major factor plays an important role in microbial nitrate uptake.

• 한국토양비료학회지
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• 제47권3호
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• pp.141-146
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• 2014

The necessity to develop economical and eco-friendly technologies is steadily increasing. Plant growth promoting rhizomicrobial strains PGPR are a group of microorganisms that actively colonize plant roots and increase plant growth and yield. Pot experiments were used to investigate the potential of some rhizobacterial strains to enhance the Brassica rapa growth. Microbial strains were successfully isolated from the rhizosphere of Panax ginseng and characterized based on its morphological and plant growth promotion characters. Surface disinfected seeds of Wisconsin Fast B. rapa were inoculated with the selected PGPR microorganisms. The different pots treatments were inoculated by its corresponding PGPR ($10^7cfu\;mL^{-1}$) and incubated in the growth chamber at $25^{\circ}C$ and 65% RH, the light period was adjusted to 24 hours (day). NPK chemical fertilizer and trade product (EMRO, USA) of effective microorganisms as well as un-inoculated control were used for comparison. Plants harvested in 40 days were found to have significant increase in leaf chlorophyll units and plant height and also in dry weight of root and shoot in the inoculated seedlings. Root and shoot length and also leaf surface area significantly were increased by bacterial inoculation in sterile soil. The study suggests that Rhodobacter capsulatus and Azotobacter chroococcum are beneficial for B. rapa growth as they enhance growth and induced IAA production and phosphorus solubilization. This study presents some rhizomicrobial strains that significantly promoted growth of Wisconsin Fast Plant B. rapa in pot experiment under different soil conditions.

• 한국환경농학회지
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• 제42권4호
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• pp.338-345
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• 2023

Bacillus spp. and Saccharomyces spp. are effective microorganisms that are applied as microbial fertilizers for crops in Korea. Mixed organic fertilizer (MOF) has been used in the Korean organic agriculture to supply nutrients to crops. This study was conducted to investigate the effects of MOF containing Bacillus amyloliquefaciens HSOB-7 and Saccharomyces cerevisiae HSOB-8 (MOFBS) on the soil chemical properties and growth of lettuce (Lactuca sativa). Growth factors of lettuce were higher after applying different formulation types of MOFBS, such as powder and pellet, than those of NF, and not significantly different than those of control (microbe-free MOF). Compared with the control, application of recommended amount of MOFBS (MOFBS 250 kg/10a, MOFBS treatment) and double the recommended amount (MOFBS 500 kg/10a, 2MOFBS treatment) did not significantly change the growth factors of lettuce. After the application of two formulation types or two different amounts of MOFBS, soil chemical properties such as electrical conductivity, organic matter (OM), exchangeable Ca, and cation exchangeable cation (CEC) increased. These results indicated that although the application of MOFBS improved soil fertility including OM and CEC, it did not significantly affect lettuce growth.

• 한국토양비료학회지
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• 제47권6호
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• pp.510-517
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• 2014

The purpose of this study was to analyze microbial hazards for cultivation environments and personal hygiene of strawberry and tomato farms at the growth and harvesting stage. Samples were collected from thirty strawberry farms and forty tomato farms located in Korea and tested for Staphylococcus aureus and Bacillus cereus. To investigate the change in the distribution of the S. aureus and B. cereus, a total of 4,284 samples including air born, soil or medium, mulching film, harvest basket, groves and irrigation water etc. were collected from eight strawberry farms and nine tomato farms for one year. As a result, total S. aureus and B. cereus in all samples were detected. Among the total bacteria of strawberry farms, S. aureus (glove: $0{\sim}2.1Log\;CFU/100cm^2$, harvest basket: $0{\sim}3.0Log\;CFU/100cm^2$, soil or culture media: 0~4.1 Log CFU/g, mulching film: $0{\sim}3.8Log\;CFU/100cm^2$), B. cereus (glove: $0{\sim}2.8Log\;CFU/100cm^2$, harvest basket: $0{\sim}4.8Log\;CFU/100cm^2$, soil or culture media: 0~5.3 Log CFU/g, mulching film: $0{\sim}4.5Log\;CFU/100cm^2$) were detected in all samples. The total bacteria of tomato farms, S. aureus (glove: $0{\sim}4.0Log\;CFU/100cm^2$, harvest basket: $0{\sim}5.0Log\;CFU/100cm^2$, soil or culture media: 0~6.1 Log CFU/g, mulching film: $0{\sim}4.0Log\;CFU/100cm^2$), B. cereus (glove: $0{\sim}4.0Log\;CFU/100cm^2$, harvest basket: $0{\sim}4.3Log\;CFU/100cm^2$, soil or culture media: 0~5.9 Log CFU/g, mulching film: $0{\sim}4.7Log\;CFU/100cm^2$) were detected in all samples. The contamination of S. aureus and B. cereus were detected in soil, mulching film and harvest basket from planting until harvest to processing, with the highest count recorded from the soil. But S. aureus and B. cereus were not detected in irrigation water samples. The incidence of S. aureus and B. cereus in hydroponics culture farm were less than those in soil culture. The amount of S. aureus and B. cereus detected in strawberry and tomato farms were less than the minimum amount required to produce a toxin that induces food poisoning. In this way, the degree of contamination of food poisoning bacteria was lower in the production environment of the Korea strawberry and tomato, but problems can be caused by post-harvest management method. These results will be used as fundamental data to create a manual for sanitary agricultural environment management, and post-harvest management should be performed to reduce the contamination of hazardous microorganisms.