• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.487-487
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• 2023

농업 분야에서 미생물은 영양분 가용화, 유기물 분해 등 토양 영양분 공급에 중요한 역할을 하며, 토양 건강성 증진, 식량 안보 및 식품 건강 면에서 많은 활용 가능성을 지니고 있다. 최근 유역 환경 건강성, 생물 다양성 보존, 효율적인 고품질 농산물 생산에 대한 관심이 커져, 지속 가능한 농업 중 하나인 유기농업과 관행농업 토양의 이화학적 및 생물학적 특성에 관한 비교 연구가 진행되고 있다. 미생물은 지속 가능한 농업 발전의 중요한 요소 중 하나로써, 미생물 다양성이 풍부할수록 토양 비옥도, 작물 성장 면에서 긍정적인 영향을 미친다고 알려져 있다. 본 연구는 이에 대한 기초 데이터를 제공하기 위해 논 경작지를 대상으로 유기 및 관행농업 토양의 미생물 군집조성과 Alpha diversity analysis(Chao1, Shannon, Simpson index)을 통해 비교하였다. 경기도 양평군에서 유기 및 관행 논 지역을 각각 1지점씩 선정하였으며, 8월부터 11월까지 총 4회 현장 조사를 진행하였다. 미생물 분석은 차세대염기서열분석을 실시하였으며, bacteria는 16S rRNA V3-4 영역, fungi는 ITS 3-4 영역을 sequencing 하였다. 미생물 군집조성은 문수준에서는 큰 차이가 없었으나, 속수준에서는 fungi 군집조성에 차이를 보였다. 예로 Ustilaginoidea 속은 관행 논 토양에서만 발견되었으며, 벼 이삭누룩병을 일으키는 병원균으로 과도한 질소 비료 시비가 원인으로 추정된다. 종 다양성은 bacteria diversity의 경우 관행 논 토양에서 높게 측정되는 반면, fungi diversity의 경우 유기 논 토양에서 높게 측정되었다. 결론적으로 체계적인 시비 관리 통해 미생물 군집은 조절될 수 있으며, 관행농업은 적절한 시비를 통해 토양 건강성 및 식품 건강성 면에서 유기농업과 비슷한 효과를 보여줄 가능성이 있다고 판단된다.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.396-407
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• 2023

The golden apple snail (Pomacea canaliculata) has been utilized as a natural and eco-friendly control of weeds in rice paddy fields. However, P. canaliculata can damage other crops. In this study, the effectiveness of plant extracts from various natural sources that are reportedly effective against pests in the control of P. canaliculata was investigated. The four plant extracts were effective against P. canaliculata and ranked in descending order as green tea seed (Camellia sinensis) > root of red spider lily (Lycoris radiata) > leaves of tobacco (Nicotiana tabacum) > root of sophora (Sophora flavescens). The mortality rate of P. canaliculata was increased using 200 to 2000 mg/kg of green tea seed powder. However, shrubby sophora root extract did not significantly increase the mortality rate. The LC₅₀ and LC₉₀ of green tea seed, tobacco leaves, shrubby sophora root, and red spider lily root were 900 and 2800 mg/L, 956 and 2320 mg/L, 2162 and 5325 mg/L, and 512 and 1054 mg/kg, respectively. The LC₅₀ and LC₉₀ of ground powder of C. sinensis, N. tabacum, S. flavescens and L. radiata were 248 and 646 mg/L, 403 and 733 mg/L, 409 and 905 mg/L, and 493 and 1141 mg/L, respectively. The findings indicate the remarkable control potency of green tea seeds against the golden apple snail. An organic material incorporating the four plant powders may help control green apple snail in an ecosystem-friendly manner.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.26-33
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• 1990

The pot experiment was conducted to compare the effects of BIO-COM (Organic fertilizer made from industrial by-product) with the compost and humic acid on the physico-chemical properties of soils and the yield of paddy rice (CV. Chucheong-byeo). The results obtained were as follows: 1. All the fertilizer treatments, except humic acid, increased rice yield compare to no fertilizer treatment, and Bio-Com was the highest among the fertilizer treatments. 2. Rice yields were increased with increasing BIO-COM only up to 4% but 2% with N.P.K. fertilizers. 3. Rice yield showed highly positive correlation with number of panicle per hill but negative correlation with 1000 grain weight. 4. BIO-COM application induced the noticeable increase of pH, EC, OM, T-N, Av-P, Ex-Ca, Ex-Mg, Ex-Na, and $Av-SiO_2$, contents in the soils after experiments, and there were highly significant positive correlation among them. 5. BIO-COM application was positively affected on plant height, number of tiller, and fresh weight and dry weight of rice plant throughout entire growing stages and these are positively correlated with rice yield. 6. BIO-COM application also induced the increase of chlorophyll, N, P, Ca, and Mg contents in rice plant 7. It is revealed that there were highly positive correlations between rice yields and pH, EC, OM, T-N, Ex-Ca, and Ex-Mg in the soils. 8. It was also shown the highly significant positive correlations between rice yields, and N and P contents in the rice plant at heading stages, respectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.3
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• pp.46-62
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• 2010

This study was conducted to understand the water and soil properties to propose the promotion of vegetation environment at farm pond depression. We selected 8 palustrine wetlands from agricultural area after consideration of human interference, surround land use, and size of area. Water quality analysis showed that the average SS, T-N, T-P were over the limit of agricultural water quality standard level at some sites. The cause for deterioration of water quality is supposed by the long-term stagnation of water in palustrine wetland. The recommended measures to improve water quality are as follows; improving water circulation by connecting with nearby natural water, preventing oxygen depletion by dredging deposit, lowering down T-N and T-P by removing autumn plants, preventing inflow of phosphorus in fertilizer ingredients which is the main cause for high T-P. The soil contamination of the surveyed area was about the same level of average heavy metal contents in soils from 2,010 paddy fields in Korea, which was much lower than soil contamination standards. As for soil texture, sand content was 40~90% and clay content was less than 20%. The content of silt and clay in soil from community of floating-leaved:submerged hydrophytes and community of emergent hydrophytes was higher that of soil from community of hygrophytes, and the content of sand in soil from community of hygrophytes was 10% higher than underwater soil. In terms of bulk density, the average was 0.24~0.96g/$cm^3$, which was quite low, because of high content of peat and organic matter in soil of the surveyed area. As for the average content of organic matter, community of floating-leaved:submerged hydrophytes was 18.25g/kg, community of emergent hydrophytes was 16.88g/kg, and community of hydrophytes was 25.63g/kg. The range of content of T-N in soil of community of floating-leaved；submerged hydrophytes was 0.022~0.307%, and that of community of emergent hydrophytes was 0.029~0.681% and that of community of hydrophytes was 0.088~0.325%. Apart from three sites in the surveyed area, most parts were over the standards or below the standard. After this study, we will conduct and discuss the relationship between vegetation characteristics and environments, which will be used of the best practical management and restoration of wetland.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.211-216
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• 2017

BACKGROUND:This study was conducted to investigate residual organochlorine pesticides (ROCPs) in agricultural soils and crops. Agricultural soil samples and crop samples were collected from 93 cities and counties. METHODS AND RESULTS: Extraction and clean-up for the quantitative analysis of ROCPs were conducted by the modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Recovery and limit of detection (LOD) of ROCPs in agriculturalsoils and crops were 76.5-103.0 and 75.2-93.2%, 0.01-0.08 and $0.10-0.15{\mu}g/kg$, respectively. Detected ROCPs in agricultural soils were ${\alpha}$-endosulfan, ${\beta}$-endosulfan, and endosulfan sulfate, the residue were 2.0-12.0, 1.2-53.1, and $2.2-329.8{\mu}g/kg$, respectively. But these pesticides in all green perilla leaf and green pepper samples were not detected. CONCLUSION: These results showed that ROCPs residues in agricultural soils were not as high as crop safety threatening.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.23-28
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• 1987

A series of field and laboratory experiments were conducted to find out the changes of some soil chemical constituents in different soil depth with three different soil textures as Bongnam-clayey, Gwanghwal-silty loam and Mangyeong fine sandy soil on the assessment of reclamation duration in Fluvio-marine soil. The result obtained were summarized as follows; 1. Exchangeable potassium, calcium, magnessium, sodium with manganes, silica and cation exchange capacity were remarkably decreased with assessment of reclamation duration. Decreasing tendency was pronounced more in sandy soil than silty loam or clayly soil. 2. Soil organic matter content in top soil was increased with increasing of reclamation years. From reclamation time, about 30 years in clayly and about 80 years in silty loam and sandy soil were necessary for the maintanance of averaged organic matter content to 2.5%. 3. Potassium activity ratio ($K/{\sqrt{Ca+Mg+Na}}$) was differed with soil depth, soil texture and assessment of reclamation duration. About 50 years is may be necessary for the maintanance of potassium activities ratio in ordinary paddy soil of 0.05-0.2. 4. Percent of adsorbed sodium (PAS), ratio of adsorbed sodium (RAS) and ratio of sodium adsorbtion(RSA) were remarkably decreased with assessment of reclamation duration. Specially, decreasing tendency was pronounced more in sandy soil than silty loam and clayly soil 5. Amount of clay content in subsoil was appearently decreased during 30 years of reclamation, but clay contents in top soil was appearently decreased 50 years after reclamation.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.41-47
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• 1972

An experiment was conducted to study the zinc deficiency of rice plant grown on Boeun soil of Korea and on Batangas soil of the philippines. The results obtained are summarized as follows: 1. Batangas soil was deficient in zinc because of the high pH, high organic matter and high calcium. Zinc content of the rice plant grown on Batangas soil was l6ppm. On the other hand, Boeun soil had low organic matter. Zinc content of the rice plant grown on Boeun soil was 33ppm. 2. The top leaf had higher zinc content than any other leaves. Zinc deficiency apparently occured when the zinc content of the rice plant was below 18ppm. 3. The physiologically acid fertilizer such as ammonium sulfate was more advantageous in improving zinc up take than the urea. 4. The zine deficiency was promoted when the Mn/Zn ratio is high, and zinc and manganess interact antagonistically in the growth of rice plant. 5. The zinc deficiency could be overcome by applying zinc chloride and fritted Trace elements to the Batangas soil, and the yield was significantly increased than conrtol.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.1
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• pp.40-48
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• 2014

Due to increasing greenhouse gas emissions, global warming and abnormal weather phenomena it has become important on a national level to keep a count of greenhouse gases being emitted. We want to take advantage of any selected area, as the basic data for the calculation of greenhouse gas emissions, Forest and Grassland, Paddy fields, and Fields(crops), Greenhouse(crops), Pig farm, Cattle farm, Farm household(populations, agricultural machinery) and Vehicle, the basic building blocks shots with a small amount of per-unit basis, the statistics calculated based on regional carbon emissions through the literature and experimental. Carbon absorption 772,960 ton C/year, amount of fixation 487,477 ton C/year, amount of emission 1,112,607 ton C/year were noted in Gimje-si, and amount of carbon absorption 55,559 ton C/year, amount of fixation 25,864 ton C/year, amount of emissions 58,355 ton C/year in Gongdeok-myeon, respectively. The carbon absorption at Hwangsan-ri is 25,107 ton C/year, fixation 4,301 ton C/year, and emission 20,330 ton C/year respectively. We were able to estimate the amount of carbon according to the specific characteristics of each unit village, then expanding it to a large-scale and comparative analysis, therefore we were able to obtain basic data on the national levels of carbon absorption.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.272-279
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• 2002

A field experiment was conducted to investigate the effect of N-use efficiency and rice yield by rapeseed cake(organic fertilizer) application at panicle initiation stage in machine transplating cultivation from 1999 to 2000. The rice yield increased by 4% in "50% rapeseed cake application", by 2% in "30% rapeseed cake application" at panicle initiation stage, respectively. Amount of fertilizer N uptake was high according to increasing amount of rapeseed cake application at panicle initiation stage compared with conventional treatment, but percentage recovery of fertilizer N was higher in 30% rapeseed cake application than in 50% rapeseed cake application at panicle initiation stage. Thus, this result was thought that there was more adventageous in 30% rapeseed cake application than 50% rapeseed cake application at panicle initiation stage in the fertilizer reduction or N-use efficiency respects in rice paddy.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.4
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• pp.77-85
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• 2010

Pig slurry has been considered as environmental waste to be treated in an appropriate manner. Recently, there has been the movement toward reusing the pig slurry as an alternative fertilizer sources for agricultural lands. For instance, SCB(Slurry Composting & Biofiltration) liquid fertilizer has been developed and widely used in Korea. However, the impacts of swine slurry liquid fertilizers on both agricultural environment and crop yield have not been investigated yet. Therefore, the current study was conducted to accumulate the basic data which can be subsequently used to determine appropriate application amount of swine slurry liquid fertilizers (SCB liquid fertilizer and storage liquid fertilizer) as well as the application method for each liquid fertilizer. For this, growth of rice was cultivated under the treatment of SCB liquid fertilizer, storage liquid fertilizer, and chemical fertilizer. Also, control treatment (no fertilizer) was included for comparison and all treatments were conducted in five replication. Rice growth was good with the treatment in the order of chemical fertilizer>storage liquid fertilizer>SCB liquid fertilizer>control and likewise, the yield amount of rice straw was in the same order of rice growth. The rice yield amount appeared to be no difference among the treatment except control which showed the least yield amount. Also there was no difference in nitrogen and phosphorus concentrations in rice among the treatment except control which showed the least concentration.