• 제목/요약/키워드: Agricultural Conditions

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바이오차를 이용한 밭 토양 탄소 저장: 동아시아 지역 연구 리뷰 및 데이터 분석 (Soil Carbon Storage in Upland Soils by Biochar Application in East Asia: Review and Data Analysis)

  • 이선일;강성수;최은정;권효숙;이형석;이종문;임상선;최우정
    • 한국환경농학회지
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    • 제40권3호
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    • pp.219-230
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    • 2021
  • BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

냉동조건에 따른 대파의 냉동저장 중 품질변화 (Changes in Quality of Welsh Onion (Allium fistulosum L.) during the Freezing Storage Period under Different Freezing Conditions)

  • 김석영;김희선;김진세;한귀정
    • 한국식품조리과학회지
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    • 제32권6호
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    • pp.665-676
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    • 2016
  • Purpose: This study was conducted to find the optimal freezing method and storage conditions for welsh onion. Methods: Cut welsh onions (0.3 cm) were packed in nylon/linear low density polyethylene (LLDPE) film bags, and frozen utilizing still-air freezing at -$20^{\circ}C$ (SAF20) and -$40^{\circ}C$ (SAF40), and immersed-liquid freezing at -$40^{\circ}C$ (ILF40); they were then stored at -$20^{\circ}C$ for 7 months. During storage, quality characteristics were measured monthly. Results: Drip loss was the lowest in the ILF40 packaging. Color difference in the stem (white part) did not differ significantly according to freezing conditions and storage time. Color difference in the leaf (green part) and stem was the lowest in SAF20. pH remained unchanged, while total aerobic bacterial count, pyruvic acid and moisture content decreased during storage. Pyruvic acid content of ILF40 was the highest among the freezing treatments. Fructose and glucose contents increased gradually during storage. Citric acid, malic acid, succinic acid and fumaric acid contents were unaffected, regardless of the freezing conditions. Conclusion: The optimal freezing method for welsh onions with the least quality changes was determined to be immersed liquid freezing, following by preservation up to 7 months by freeze-storing.

Adsorption characteristics of NH4-N by biochar derived from pine needles

  • Kang, Yun-Gu;Lee, Jun-Young;Chun, Jin-Hyuk;Lee, Jae-Han;Yun, Yeo-Uk;Oh, Taek-Keun
    • 농업과학연구
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    • 제48권3호
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    • pp.589-596
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    • 2021
  • Nitrogen applied to soil is highly prone to leaching and volatilization leading to gaseous emissions of nitrous oxide (N2O) and ammonia (NH3) which are of great environmental concern. Usage of biochar to reduce the discharge of nitrogen to the environment has attracted much interest in the recent past. Biochar is produced by pyrolyzing various biomasses under oxygen-limited conditions. Biochar is a carbonized material with high adsorptive powers for not only plant nutrients but also heavy metals. The objective of this study was to investigate the adsorption characteristics of NH4-N onto biochar made from pine needles. The biochar was produced at various pyrolysis temperatures including 300, 400 and 500℃ and holding times of 30 and 120 minutes. The Langmuir isotherm was used to evaluate the adsorption test results. The chemical properties of the biochar varied with the pyrolysis conditions. In particular, the pH, EC and total carbon content increased with the increasing pyrolysis conditions. The rate of adsorption of NH4-N by the biochar decreased with the increasing pyrolysis conditions. Of these conditions, biochar that was pyrolyzed at 300℃ for 30 minutes showed the highest adsorption rate of approximately 0.071 mg·g-1. Thus, the use of biochar pyrolyzed at low temperatures with a short holding time can most efficiently reduce ammonia emissions from agricultural land.

Optimization of the extraction process of high levels of chlorogenic acid and ginsenosides from short-term hydroponic-cultured ginseng and evaluation of the extract for the prevention of atopic dermatitis

  • Lee, Tae Kyung;Lee, Ji Yun;Cho, Yeon-Jin;Kim, Jong-Eun;Kim, Seo Yeong;Park, Jung Han Yoon;Yang, Hee;Lee, Ki Won
    • Journal of Ginseng Research
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    • 제46권3호
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    • pp.367-375
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    • 2022
  • Background: Short-term hydroponic-cultured ginseng (sHCG), which is 1-year-old ginseng seedlings cultivated for 4 weeks in a hydroponic system, is a functional food item with several biological effects. However, the optimal extraction conditions for sHCG, and the bioactivity of its extracts, have not been evaluated. Methods: Chlorogenic acid (CGA) and ginsenoside contents were evaluated in sHCG, white ginseng (WG), and red ginseng (RG) using high-performance liquid chromatography. Response surface methodology (RSM) was used to optimize the extraction conditions (temperature and ethanol concentration) to maximize the yield of dry matter, CGA, and four ginsenosides (Re, Rg1, Rb1, and Rd) from sHCG. The optimal extraction conditions were applied to pilot-scale production of sHCG extracts. The expression levels of tumor necrosis factor (TNF)-α/interferon (IFN)-γ-induced thymic and activation-regulated chemokines (TARC/CCL17) were measured after treatment with sHCG, WG, and RG extracts, and the effects of their bioactive compounds (CGA and four ginsenosides) on human skin keratinocytes (HaCaTs) were evaluated. Results: CGA and four ginsenosides, which are bioactive compounds of sHCG, significantly inhibited TNF-α/IFN-γ-induced TARC/CCL17 expression. The optimal sHCG extraction conditions predicted by the RSM models were 80 ℃ and 60% ethanol (v/v). The sHCG extracts produced at the pilot scale under optimal conditions greatly alleviated TNF-α/IFN-γ-induced TARC/CCL17 production compared with WG and RG extracts. Conclusions: Pesticide-free sHCG extracts, which contain high levels of CGA and the ginsenosides Re, Rg1, Rb1, and Rd as bioactive compounds, may have therapeutic potential for atopic diseases.

Growth and yield responses of rice varieties to various soil water deficit conditions under different soil types

  • Kikuta, Mayumi;Samejima, Hiroaki;Magoti, Rahab;Kimani, John M.;Yamauchi, Akira;Makihara, Daigo
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.322-322
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    • 2017
  • To avoid drought stress under rainfed upland conditions, it is important for rice to efficiently utilize water at shallow soil layers supplied by rainfall, and access to water retained in deer soil layers. The root developmental characteristics of rice, which play important role in the adaptability to drought conditions, vary depending on the variety. Moreover, water availability for plant differs depending on the soil types that have different physical properties such as water holding capacity, permeability, capillary force, penetration resistance, etc. In this study, we evaluated growth and yield responses of rice varieties to various soil water deficit conditions under three different soil types. The experiment was conducted in a plastic greenhouse at the Kenya Agricultural and Livestock Research Organization-Mwea from October 2016 to January 2017. Two upland varieties (NERICA 1 and 4) and one lowland variety (Komboka) were grown in handmade PVC pots (15.2 cm diameter and 85.0 cm height) filled with three different types of soil collected from major rice-growing areas of the country, namely black cotton (BC), red clay (RC), and sandy clay (SC). Three watering methods, 1) supplying water only from the soil surface (W1), 2) supplying water only from the bottom of the pots (W2), and 3) supplying water both from the soil surface and the bottom of pots (W3), were imposed from 40 days after sowing to maturity. Soil water content (SWC) at 20, 40, and 60 cm depths was measured regularly. At the harvesting stage, aboveground and root samples were collected to determine total dry weight (TDW), grain yield, and root length at 0-20, 20-40, 40-60, and 60-80 cm soil layers. Irrespective of the watering methods, the greatest root development was obtained in RC, while that in BC was less than other two soils. In BC, the degree of yield reduction under W1 was less than that in RC and SC, which could be attributed to the higher water holding capacity of BC. In RC, the growth and yield reduction observed in all varieties under W1 was attributed to the severe drought stress. On the other hand, under W2, SWC at the shallow soil depth in RC was maintained because of its higher capillary force compared with BC and SC. As the result, growths and yields in RC were not suppressed under W2. In SC, deep root development was not promoted by W2 irrespective of the varieties, which resulted in significant yield losses. Under W1, the rice growth and yield in SC was decreased although shallow root development was enhanced, and the stomatal conductance was maintained higher than RC. It was suspected that W1 caused nutrients leaching in SC because of its higher permeability. Under rainfed conditions, growth and yield of rice can be strongly affected by soil types because dynamics of soil water conditions change according to soil physical properties.

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반응표면분석법을 이용한 대추잎 항산화물질의 에탄올추출조건 최적화 (Optimization of Ethanol Extraction Conditions for Antioxidants from Zizyphus jujuba Mill. Leaves Using Response Surface Methodology)

  • 민들레;임석원;안준배;최영진
    • 한국식품과학회지
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    • 제42권6호
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    • pp.733-738
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    • 2010
  • 대추잎 항산화 물질의 고효율 추출을 위한 에탄올 용매추출조건을 반응표면분석법을 사용하여 최적화하였다. Box-Behnken design에 따라 추출공정 조작변수(온도, 시간, 에탄올 농도)를 독립변수로, 이에 따라 영향을 받는 종속변수(총 폴리페놀 함량, 총 플라보노이드 함량, 전자공여능)를 설정하여 실험하였다. 추출물의 총 폴리페놀 함량과 총 플라보노이드 함량은 시간과 온도의 영향을 거의 받지 않으며, 용매비가 높을수록 증가하다가 최고점을 보인 후 다시 감소하는 경향을 나타내었다. 전자공여능 또한 시간과 온도의 영향보다는 용매비에 영향을 많이 받는데, 에탄올 농도가 높을수록 전자공여능이 높게 측정되었다. 추출물의 특성을 모두 만족시키는 최적 추출조건 범위 내에서 임의의 조작조건(온도 $45^{\circ}C$, 시간 15분, 에탄올 농도 45%)을 설정하였다. 최적조건에서 예측값과 실험값을 비교한 결과, 유사한 값을 보여주어 회귀식이 신뢰할 수 있음을 알 수 있었다.

Studies on the Genesis of Ginseng Rust Spots

  • Wang, Yingping;Li, Zhihong;Sun, Yanjun;Guo, Shiwei;Tian, Shuzhen;Liu, Zhaorong
    • Journal of Ginseng Research
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    • 제21권2호
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    • pp.69-77
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    • 1997
  • In order to explain the connection between ginseng rust spot and soil ecological conditions, the bed soils and ginseng roots were sampled at different microrelief units and the reducing substances of the bed soils and iron forms of the ginseng root epi dermises were determined. The results showed that the occurrence of the rust spot was connected with the ecological conditions of the soils and the metabolism of the plant which was caused by the excessive $Fe^{2+}$ in the soil solution. Ginseng rust spot was the enrichment of iron which was mainly composed of organic complex irons. Including active ferrous active ferric and non active ferric forms and they were transformed into each other following the change of soil moisture and temperature regimes. According to the regularity of growth and decline of reducing substances in soil and rust index of ginseng roots as well as the difference of adaptability to excessive $Fe^{2+}$ in soil among different year-old seeding, a new comprehensive measure based on the connection of ameliorating soil and improving cultivation system was recommended to prevent the occurrence of ginseng rust spot.

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그린벨트내 개발행위허가 규제제도의 변천에 관한 연구 - 농림수산업용 시설을 중심으로 - (Study on Reform of Development Regulations in Greenbelt - Focused on Agricultural, Forestry and Fisheries Facilities -)

  • 이상원;사또요헤이
    • 농촌계획
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    • 제6권1호
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    • pp.10-18
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    • 2000
  • The objective of this study is to analyze 1) the law system in relation with the development permissions 2) characteristics of the development permissions change 3) especially focusing on the development permissions changes in agricultural, forestry and fisheries facilities in light of socio - economic conditions in Korea Greenbelt. The following results were obtained: 1) The purpose of Greenbelt in Korea is to control the land use in order to protect the surrounding areas from urbanization. 2) During the 1990s, the number of formulated development regulations increased one and half times than that of the previous decades(1970s 1980s). The main reasons are advancements of local autonomy and democratization. 3) Three patterns were observed with respect to ease the regulations in agricultural, forestry and fisheries facilities those are: (1) increase in types of businesses ; (2) increase the maximum area permitted ; (3) decrease in qualification for establishing facilities. 4) There were few development permissions in a agricultural, forestry and fisheries facilities in consideration to the regional agricultural condition. The development permissions were only during the period of restricted to use ($1979.12{\sim}1993.11$). We propose that the authority of development permission should be given to the local autonomy government, because the local government has the knowledge of its individual agricultural conditions.

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Effects of Temperature and Humidity on Fungal Occurrence in Dried Red Pepper during Storage

  • Kim, Sosoo;Baek, Seul Gi;Hung, Nguyen Bao;Kim, Se-Ri;Jang, Ja Yeong;Kim, Jeomsoon;Lee, Theresa
    • 식물병연구
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    • 제27권4호
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    • pp.155-163
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    • 2021
  • Dried red peppers are frequently contaminated with mycotoxins during storage. To determine the effect of storage environments on fungal occurrence and subsequent mycotoxin accumulation in dried red peppers, we monitored red pepper powder and whole fruit samples for fungal occurrence under various temperatures and relative humidity (RH) conditions during 340 days. Fungal occurrences fluctuated in both pepper forms throughout the storage but they were higher in pepper powder than whole one, higher under low temperatures (-20℃, 0℃, or 4℃) than others (10℃, 25℃, or 30℃), and higher under RH 93% than RH 51% and 69% in both peppers. The samples exhibiting high fungal occurrences were associated mainly with dominant species such as Aspergillussydowii, Penicillium solitum, P. roqueforti, P. polonicum, or P. chrysogenum. Mycotoxigenic species, including A. flavus, A. ochraceus, A. westerdijkiae, A. tubingensis, and P. citrinum, were also detected throughout the samples. Although mycotoxins were not detected in the samples, mycotoxigenic potential of A. flavus, A. ochraceus, and A. westerdijkiae isolates were confirmed. These results show that low temperatures (-20℃, 0℃, or 4℃) and/or high surrounding RH (>93%) are not safe environments for storage of dried red peppers as fungal growth can occur under these conditions.