토양 수분 변동 조건에서 시비 및 유기물 투입에 따른 CO₂와 CH₄ 방출 특성

임상선,최우정,김한용,Lim, Sang-Sun,Choi, Woo-Jung,Kim, Han-Yong 한국환경농학회 2012 한국환경농학회지 Vol.31 No.2

논 생태계를 모의하여 토양에 투입된 비료의 종류(AS, PMC, HV)와 토양 수분 변동조건(습윤기간, 전이기간, 건조 기간)으로 구분하여 $CH_4$과 $CO_2$ 플럭스를 조사하였다. $CH_4$ 플럭스는 0~13.8 mg $CH_4$/m/day의 범위에서 변화하였으 며, 시기적으로 습윤기간 초기와 전이기간과 건조기간 경계 시점에서 높은 값을 보였다. $CO_2$ 플럭스는 습윤 초기에 최대 치를 보이고 지속적으로 감소하다가 전이기간에 다시 상승하 였다. 최종토양의 탄소함량 변화는 대조구에서-5.4%이었고, 비료 처리구에서는-7.5~-16.4%이었다. HV 시용은 타 비종 에 비해 $CH_4$과 $CO_2$ 플럭스를 증가시켰는데, 이는 녹비작물 이 가축분 퇴비에 비해 상대적으로 이분해성으로 배양 초기 에 유기물 분해에 의해 $CH_4$과 $CO_2$ 발생량이 높았기 때문이 다. AS나 PMC 처리구에서 $CH_4$ 플럭스가 대조구에 비해 낮았는데, 이는 AS의 ${SO_4}^{2-}$와 퇴비에 함유된 산화형 물질($Fe^{3+}$, $Mn^{4+}$, ${NO_3}^-$)과 같은 전자 수용체에 의해 습윤기간 중 이들 물질이 전자수용체로 활용되어 $CH_4$ 생성이 감소할 수 있음 을 의미한다. PMC와 HV의 탄소 손실률을 비교하면, HV와 같은 이분해성 유기물에 비해 PMC와 같은 난분해성 유기물 의 시용이 토양 탄소량을 증가시키는 것으로 나타났다. 또한, 본 연구는 HV와 같은 녹비 작물이 질소 공급의 측면에서 화 학비료를 대체할 수 있지만, 화학비료 시용에 비해 $CH_4$ 발생 이 증가할 수 있음을 제시한다. 따라서, 이분해성 유기물(녹비 작물)과 난분해성 유기물(가축분퇴비)을 혼합 시용할 경우 양 분공급과 탄소저장량 증대에 모두 유리할 것으로 기대된다. BACKGROUND: Agricultural inputs (fertilizer and organic inputs) and water conditions can influence $CH_4$ and $CO_2$ emission from agricultural soils. This study was conducted to investigate the effects of agricultural inputs (fertilizer and organic inputs) under changing water regime on $CH_4$ and $CO_2$ emission from a soil in a laboratory incubation experiment. METHODS AND RESULTS: Four treatments were laid out: control without input and three type of agricultural inputs ($(NH_4)_2SO_4$, AS; pig manure compost, PMC; hairy vetch, HV). Fertilizer and organic inputs were mixed with 25 g of soil at 2.75 mg N/25 g soil (equivalent to 110 kg N/ha) in a bottle with septum, and incubated for 60 days. During the first 30-days incubation, the soil was waterlogged (1 cm of water depth) by adding distilled water weekly, and on 30 days of incubation, excess water was discarded then incubated up to 60 days without addition of water. Based on the redox potential, water regime could be classified into wetting (1 to 30 days), transition (31 to 40 days), and drying periods (41 to 60 days). Across the entire period, $CH_4$ and $CO_2$ flux ranged from 0 to 13.8 mg $CH_4$/m/day and from 0.4~1.9 g $CO_2$/m/day, and both were relatively higher in the early wetting period and the boundary between transition and drying periods. During the entire period, % loss of C relative to the initial was highest in HV (16.4%) followed by AS (8.1%), PMC (7.5%), and control (5.4%), indicating readily decomposability of HV. Accordingly, both $CH_4$ and $CO_2$ fluxes were greatest in HV treatment. Meanwhile, the lower $CH_4$ flux in AS and PMC treatments than the control was ascribed to reduction in $CH_4$ generation due to the presence of oxidized compounds such as ${SO_4}^{2-}$, $Fe^{3+}$, $Mn^{4+}$, and ${NO_3}^-$ that compete with precursors of $CH_4$ for electrons. CONCLUSION: Green manure such as HV can replace synthetic fertilizer in terms of N input, however, it may increase $CH_4$ emission from soils. Therefore, co-application of green manure and livestock manure compost needs to be considered in order to achieve satisfactory N supply and to mitigate $CH_4$ and $CO_2$ emission.

IT융합기술이 접목된 Smart Food Court 급식 시스템 연구

임상선,박대우,Lim, Sang-Seon,Park, Dea-Woo 한국전자통신학회 2011 한국전자통신학회 논문지 Vol.6 No.5

Feed industry began to demand that beyond simple feeds to meet the needs of customers with a premium catering by economic development situation and, depending on the user's convenience and customer needs. But tableware introduced in the feed system, the introduction of RFID. High and low temperatures and salinity problems that RFID chips, the feed system malfunction. In this paper, infused with IT Convergence Technology was carried out for a smart lunch by putting RFID chips in the Food Court distribute food. Food court meal to ensure stability of the system was a smart lunch that Hot food ($125^{\circ}C$) and cold ($-40^{\circ}C$) and salinity reflecting foods in High temperature, low temperature experiments, through salt spray test. In addition, the existing straight distribute food, scramble distribute food, Marketplace distribute food, Food Court and the advantages of a comparative analysis of distribute food investigated. Through this paper distribute food will contribute to the Food Court. IT convergence technology (RFID, LCD, S/W, H/W) to apply the feed industry in the development of Smart Food Court. 급식산업은 경제발전상황과 사용자의 편의성 및 고객욕구에 따라 단순급식을 벗어나 고객의 욕구를 만족시킬 수 있는 프리미엄급 급식을 요구하기 시작하였다. 급식 시스템에 도입된 식기에 RFID을 도입 하였으나, 고온과 저온 및 염도에 RFID 칩이 오작동하여 급식시스템에 문제가 발생하였다. 본 논문에서는 IT융합기술이 접목된 스마트 급식을 위하여 Food Court 배식에 RFID 칩을 넣어서 실험을 하였다. Food court 급식 시스템에서 뜨거운 음식($125^{\circ}C$)과 차가운 음식($-40^{\circ}C$) 및 염분이 함유된 음식을 반영하여 고온, 저온 실험, 염수 분무 실험을 통하여 스마트 급식의 안정성을 확보 하였다. 또한 기존의 일자형 배식, 스크램블형 배식, Marketplace 배식, Food Court 배식을 비교 분석하고 장점을 연구하였다. 본 논문연구를 통하여 Food Court 배식에 IT융합 기술인(RFID, LCD, S/W, H/W)을 적용하는 스마트 Food Court 급식산업발전에 기여할 것이다.

항온 배양 논토양 조건에서 비산재 처리에 따른 CH₄와 CO₂ 방출 특성

임상선,최우정,김한용,정재운,윤광식,Lim, Sang-Sun,Choi, Woo-Jung,Kim, Han-Yong,Jung, Jae-Woon,Yoon, Kwang-Sik 한국토양비료학회 2012 한국토양비료학회지 Vol.45 No.5

비산재 혼합에 의한 $CH_4$과 $CO_2$ 방출 저감 가능성을 조사하기 위해 질소 ($(NH_4)_2SO_4$) 무처리구와 처리구를 두고 비산재를 0, 5, 10% 수준으로 혼합한 후 토양 수분 변동조건 (습윤기간, 전이기간, 건조기간)에서 60일간 실험실내 항온배양실험을 통해 $CH_4$과 $CO_2$ flux를 분석하였다. 전체 항온배양기간 중 평균 $CH_4$ flux는 $0.59{\sim}1.68mg\;CH_4\;m^{-2}day^{-1}$의 범위였으며, 질소 무처리구에 비해 처리구에서 flux가 낮았는데, 이는 질소 처리시 함께 시용된 $SO_4^{2-}$의 전자수용체 기능에 의해 $CH_4$ 생성이 억제되었기 때문으로 판단되었다. 질소 무처리구와 처리구에서 비산재 10% 처리에 의해 $CH_4$ flux가 각각 37.5%와 33.0% 감소하였는데, 이는 물리적인 측면에서 미립질 (실트 함량 75.4%)인 비산재 시용에 의해 통기성 대공극량이 감소되어 $CH_4$ 확산 속도가 저감되었기 때문으로 판단되었다. 또한, 생화학적 측면에서는 비산재의 $CO_2$ 흡착능에 의해 $CH_4$ 생성의 주요 기작 중 하나인 이산화탄소 환원에 필요한 $CO_2$ 공급이 억제된 것도 원인 일 수 있다. 한편, 전체 항온 배양 기간의 평균 $CO_2$ flux ($0.64{\sim}0.90g\;CO_2\;m^{-2}day^{-1}$) 역시 질소 무처리구가 질소 처리구보다 높았다. 이는 일반적으로 질소 시비에 의해 토양 호흡량이 증가한다는 기존의 연구결과와는 상이한데, 본 연구에서 질소 처리에 의해 활성화된 미생물에 의해 $CO_2$ flux 최초 측정 시점 (처리 후 2일째) 이전에 이미 상당한 양의 $CO_2$가 이미 방출되어 실측 flux에 반영되지 못했기 때문으로 설명이 가능했다. $CH_4$과 유사하게 $CO_2$ flux도 비산재무처리구에 비해 비산재 10% 처리구에서 약 20% 감소하였는데, 이는 비산재의 원소 구성 중 Ca과 Mg과 토양수내 탄산이온의 탄산염 ($CaCO_3$과 $MgCO_3$)화 반응에 의한 $CO_2$ 침전 때문이다. 이상과 같은 비산재 처리에 의한 $CH_4$과 $CO_2$ flux 감소에 의해 지구온난화지수 역시 비산재 10% 처리구에서 약 20% 감소하였다. 따라서, 비산재는 논 토양에서 $CH_4$과 $CO_2$ 방출 저감에 효과가 있는 것으로 나타났으며, 실재 벼 재배 포장에서의 실험을 통한 추가적인 검증이 필요하다. To estimate potential use of fly ash in reducing $CH_4$ and $CO_2$ emission from soil, $CH_4$ and $CO_2$ fluxes from a paddy soil mixed with fly ash at different rate (w/w; 0, 5, and 10%) in the presence and absence of fertilizer N ($(NH_4)_2SO_4$) addition were investigated in a laboratory incubation for 60 days under changing water regime from wetting to drying via transition. The mean $CH_4$ flux during the entire incubation period ranged from 0.59 to $1.68mg\;CH_4\;m^{-2}day^{-1}$ with a lower rate in the soil treated with N fertilizer due to suppression of $CH_4$ production by $SO_4^{2-}$ that acts as an electron acceptor, leading to decreases in electron availability for methanogen. Fly ash application reduced $CH_4$ flux by 37.5 and 33.0% in soils without and with N addition, respectively, probably due to retardation of $CH_4$ diffusion through soil pores by addition of fine-textured fly ash. In addition, as fly ash has a potential for $CO_2$ removal via carbonation (formation of carbonate precipitates) that decreases $CO_2$ availability that is a substrate for $CO_2$ reduction reaction (one of $CH_4$ generation pathways) is likely to be another mechanisms of $CH_4$ flux reduction by fly ash. Meanwhile, the mean $CO_2$ flux during the entire incubation period was between 0.64 and $0.90g\;CO_2\;m^{-2}day^{-1}$, and that of N treated soil was lower than that without N addition. Because N addition is likely to increase soil respiration, it is not straightforward to explain the results. However, it may be possible that our experiment did not account for the substantial amount of $CO_2$ produced by heterotrophs that were activated by N addition in earlier period than the measurement was initiated. Fly ash application also lowered $CO_2$ flux by up to 20% in the soil mixed with fly ash at 10% through $CO_2$ removal by the carbonation. At the whole picture, fly ash application at 10% decreased global warming potential of emitted $CH_4$ and $CO_2$ by about 20%. Therefore, our results suggest that fly ash application can be a soil management practice to reduce green house gas emission from paddy soils. Further studies under field conditions with rice cultivation are necessary to verify our findings.

Dry Matter Yield and Nutrients Uptake of Sorghum${\times}$Sudangrass Hybrid Grown with Different Rates of Livestock Manure Compost

임상선,이상모,이승헌,최우정,Lim, Sang-Sun,Lee, Sang-Mo,Lee, Seung-Heon,Choi, Woo-Jung Korean Society of Soil Science and Fertilizer 2010 한국토양비료학회지 Vol.43 No.4

To investigate the growth and nutrient uptake response of sorghum${\times}$sudangrass ($S{\times}S$) hybrid to different rate of livestock manure compost, a field experiment was conducted in the experimental grassland of Chonnam National University. Six treatments were laid out in a randomized block design with triplicates; control (no input), synthetic fertilizer (20 g N $m^{-2}$ and 20 g $P_2O_5\;m^{-2}$), compost 1 (3.4 g N $m^{-2}$ and 3.6 g $P_2O_5\;m^{-2}$), compost 2 (6.8 g N $m^{-2}$ and 7.2 g $P_2O_5\;m^{-2}$), compost 4 (13.4 g N $m^{-2}$ and 14.4 g $P_2O_5\;m^{-2}$), and compost 6 (20.2 g N $m^{-2}$ and 21.6 g $P_2O_5\;m^{-2}$). Ninety days after treatment, above-ground parts of the plants were harvested and measured for dry matter yield (DMY) and amounts of nutrients (N and P) uptake. Synthetic fertilizer application achieved the greatest DMY (2.4 kg $m^{-2}$) and nutrient uptake (38.3 g N $m^{-2}$ and 15.3 g $P_2O_5\;m^{-2}$). Increasing compost application rate tended to enhance DMY accumulation and nutrient uptake (P<0.01), but DMYs of compost 4 (1.9 kg $m^{-2}$) and 6 (1.8 kg $m^{-2}$) treatments were not different. Therefore, it was suggested that application compost alone may not achieve DMY of $S{\times}S$ hybrid compatible to synthetic fertilizer application. As nutrient uptake efficiency data showed that availability of compost P could be better than SF, it might be a strategy to apply compost as P source with supplementary N application such as liquid manure, SF or green manure if necessary considering availability of N input and the yield goals. 가축분 퇴비 시용 수준에 따른 수수${\times}$수단그라스 ($S{\times}S$ hybrid)의 수량 및 양분 (N, P)흡수 변이를 조사하기 위해 전남대학교 부속 농장 초지에서 3반복 난괴법으로 실험을 실시하였다. 6개 처리 (무비구, 화학비료관행구, 퇴비 1, 2, 4, 6 수준)를 두었는데, 화학비료관행구의 비료 처리량은 질소 20 g N $m^{-2}$과 인산 20 g $P_2O_5\;m^{-2}$이고, 가축분 퇴비는 6 수준을 기준시비량 (20.2 g N $m^{-2}$과 21.6 g $P_2O_5\;m^{-2}$)으로 두고 퇴비 1, 2, 4 수준은 그 비율대로 감비하였다. 처리 90일 후 최종 지상부 건물중과 양분 (N, P) 흡수량을 조사하였다. 화학비료 처리구의 건물중 (2.4 kg $m^{-2}$)과 질소 (38.3 g N $m^{-2}$) 및 인산 (15.3 g $P_2O^5\;m^{-2}$) 흡수량이 가장 높았으며, 퇴비 시용량이 증가함에 따라 건물중과 양분 흡수량이 증가하는 경향을 보였다 (P<0.01). 하지만, 퇴비 4와 6 수준의 건물중은 각각 1.9 kg $m^{-2}$과 1.8 kg $m^{-2}$으로 차이가 없었다. 따라서, 가축분 퇴비 단독 시비로는 화학비료와 대등한 건물 생산이 어려울 것으로 판단되었다. 양분흡수효율 분석 결과에 의하면 퇴비의 인산흡수 효율이 화학비료보다 높았기 때문에, 퇴비를 인산 급원으로 시용하고 부족한 질소는 농가의 비료자원 수급 가능성과 목표 수량을 고려하여 액비, 화학비료, 녹비 등으로 공급하는 것이 적절한 시비 전략으로 판단된다.

이화학성이 상이한 가축분퇴비가 시용된 인셉티솔, 울티솔, 안디솔 토양의 탄소 무기화 포텐셜

임상선 ( Sang-sun Lim ),이선일 ( Sun-il Lee ),박현정 ( Hyun-jung Park ),이동석 ( Dong-suk Lee ),곽진협 ( Jin-hyeob Kwak ),최우정 ( Woo-jung Choi ) 한국농공학회 2009 한국농공학회 학술대회초록집 Vol.2009 No.-

To investigate the interactive effects of composts and soils on C mineralization of compost-amended soils and to identify the principal physcio-chemical variables that affect C mineralization, a 100-day incubation experiment was conducted using three soils (Inceptisol, Ultisol, and Andisol) and seven composts with different characteristics. The cumulative CO₂-C (% C_m) evolved through the experiments expressed as % of added total organic C (TOC) of the composts ranged from 1.7 to 17.1% with significant reduction in Andisol that has an ability to reduce C mineralization by forming Al-organic matter complex. However, compost that had the highest easily decomposable organic-C (K₂SO₄ extractable organic-C) still had a % C_m compatible to Inceptisol and Ultisol, suggesting that there was a significant interaction between compost and soil types. Concentration of K₂SO₄ extractable organic-C in the composts also affected the temporal pattern of CO₂-C evolution;i.e. application of compost with a relatively lower extractable organic-C resulted in a delayed peak CO₂-C probably due to lower concentration of substrate for initial microbial activity. Meanwhile, NO₃ ^- concentration in the composts that is an indicator of compost maturity was negatively correlated with % C_m. Therefore, our study suggests that NO₃ ^- and easily decomposable organic-C concentrations in the composts were the most influencing factors controlling compost C mineralization in our study. Kinetic model approach was very useful in understanding the mechanism underlying the observed CO₂-C evolution pattern because it provides pool size of mineralizable C and mineralization rate. (This study was supported by the Technology Development Program for Agriculture and Forestry, Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea)

연구보문 : 토양환경 ; 우분뇨 퇴비화 중 암모니아 휘산에 대한 이분해성 및 난분해성 유기 첨가물의 역할

임상선 ( Sang Sun Lim ),박현정 ( Hyun Jung Park ),이선일 ( Sun Il Lee ),이동석 ( Dong Suk Lee ),곽진협 ( Jin Hyeob Kwak ),최우정 ( Woo Jung Choi ) 한국환경농학회 2009 한국환경농학회지 Vol.28 No.1

퇴비화 과정 중 암모니아 휘산과 관련된 난분해성 및 이분해성 유기물의 역할을 재조명하기 위해 분뇨와 톱밥 (난분해성 또는 쌀겨(이분해성)를 혼합한 후 4주간 CO2 발생량과 NH3 휘산량을 조사하였다. 이산화탄소 발생량은 톱밥처리구에 비해 쌀겨처리구에서 43~122% 정도 높았으며, 이에 상응하게 최종 건물중 손실률도 쌀겨처리구가 35.1~41.5%로 톱밥처리구의 18.7~22.6%에 비해 유의하게(P<0.05) 높았다. 톱밥처리구에서는 시험기간인 4주간 암모니아 휘산이 발생하지 않았는데, 이는 톱밥의 C/N 비가 높아 질소무기화가 지체되었고 톱밥 자체가 NH4+를 흡착할 수 있는 능력이 있기 때문으로 판단되었다. 반면, 이분해성인 쌀겨 처리구에서는 퇴비화 초기에는 질소부동화에 의해 암모니아 휘산이 나타나지 않았지만, 8일 이후부터는 쌀겨처리량이 낮은 순서대로 이분해성 유기물의 고갈에 의한 질소재무기화에 의해 암모니아 휘산이 관측되었다. 따라서, 이분해성 유기물은 초기 암모니아 부동화를 통해 암모니아 휘산을 감소시킬 수 있지만, 부동화된 질소의 재무기화에 의해 퇴비화 중반기에 오히려 암모니아 휘산이 증가할 수 있는 것으로 나타났다. 반면, 난분해성 유기물인 톱밥은 암모니아 고정능이 있어 물리화학적 흡착에 의해 암모니아 휘산을 저감시킬 수 있는 것으로 판단되었다. This study was conducted to investigate the roles of co-existed organic materials (OM) with different biodegradability in composting of cattle manure in terms of CO2 emission and NH3 volatilization. Either sawdust (SD, low biodegradability) or rice bran (RB, high biodegradability) was mixed with cattle manure at a various rate and the amounts of CO2 emission and NH3 volatilization were determined periodically during 4 weeks of composting. Percentage of dry matter loss during the composting period was also calculated. The amount of CO2 emitted increased with increasing rate of OM and was significantly (P<0.01) higher in the RB treatment than in the SD treatment by 43 to 122%depending on the rate of OM. Accordingly, %of dry matter loss during 4 weeks of composting was higher in the RB (rang: from 35.1% to 41.5%) than that in the SD treatments (from 18.7% to 22.6%), showing that RB is more biodegradable than SD. During the early composting period up to 8 days, negligible amount of ammonia volatilization was detected in both treatments regardless of application rates. In the RB treatment, substantial amount of ammonia volatilization was detected thereafter; however, no meaningful ammonia volatilization was observed in the SD treatment until the end of composting. Such differences could be attributed to the different properties of SD and RB. For example, the high C/N ratio of SD could enhance NH4+ immobilization and thus decrease NH4+ concentration that is susceptible to ammonia volatilization. Binding of NH4+ on to phenolic compounds of SD may also contribute to the decrease in NH4+ concentration. Meanwhile, as RB has a relatively low C/N ratio, remineralization of immobilized NH4+ could increase NH4+ concentration as high as the level for the occurrence of ammonia volatilization. Therefore, our study suggests that OM which is resistant to biodegradation can reduce NH3 volatilization largely by physicochemical pathways across the entire composting period and that easily biodegradable OM can retard NH3 volatilzation via microbial immobilization in the early period of composting followed by rapid remineralization, leading to substantial volatilization of NH3 in the middle stage of composting.

우분뇨 퇴비화 기간 중 질소동위원소비 변화

임상선 ( Lim Sang Sun ),최우정 ( Choi Woo Jung ),곽진협 ( Kwak Jin Hyeob ),정재운 ( Jung Jae Woon ),윤광식 ( Yoon Kwang Sik ),김한용 ( Kim Han Yong ),김영주 ( Kim Young Joo ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

Composted livestock-manure has a higher N isotope ratio(¹⁵N/¹⁴N, expressed as δ¹⁵N) than synthetic fertilizer; and thus using N isotope ratio(¹⁵N/¹⁴N, expressed as δ¹⁵N) of crops as a potential indicator of N inputs(composted livestock-manure vs, synthetic fertilizer) has been extensively tested recently. However, variation in δ¹⁵N during composting has never been investigated. In this study, we investigated temporal variations in δ¹⁵N during composting of cattle feedlot manure using either rice bran (RBM) or sawdust (SDM) as bedding materials. Regardless of bedding materials, the δ¹⁵N of total N incresed from +7.6 to +9.9‰ in RBM and from +11.4 to +14.3‰ in SDM within 10 days of composting. Such an increase could be attributed primarily to N loss via NH₃ volatilization and denitrification that increase δ¹⁵N of remaining N pool due to isotopic fractionation. In spite of a higher NH₃ volatilization potential in RBM as indicated by a higher pH and a lower NH₄⁺ concentration than those in SDM, the δ¹⁵N of total N in RBM was substantially lower than that in SDM by more than 3‰. These results indicated that the δ¹⁵N of compost was likely to be affected not only by N loss but also by bedding material. Because rice bran (4.2g kg^-1) contained ten times higher N concentration than sawdust (0.4g kg^-1) and its δ¹⁵N(+4.9‰)was lower than that (+7.6~+11.0‰) of total N in the compost mixture, isotope dilution effect of N derived from relatively ¹⁵N-depleted bedding materials on lowering δ¹⁵N of compost would be greater in RBM than in SDM. therefore, it was expected that less input of N as bedding materials would result in a higher δ¹⁵N of livestock manure compost if other conditions are the same.

퇴비화 첨가물에 따른 암모니아 휘산 기작 구명

임상선 ( Lim Sang Sun ),곽진협 ( Kwak Jin Hyeob ),박현정 ( Park Hyun Jung ),이선일 ( Lee Sun Il ),이동석 ( Lee Dong Suk ),최우정 ( Choi Woo Jung ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

Nitrogen loss via ammonia volatilization during the early period of composting process decreases N concentration in the final compost, leading to imbalance between N/P in the compost and crop requirement of N/P. Application of compost at the rate to meet crop requirement of N freqently resulted in accumulation of soil P. Therefore, it is urgent to develop composting techniques to reduce ammonia volatilization loss. Understanding of the ammonia volatilization patterns as affected by co-existed organic matter added to manure for enhancement of composting process may be helpful in developing such composting techniques. In this study, we investigated the effect of different organic amendment in terms of biodegradability on ammonia volatilization during 4 weeks of composting in a continuous-flow experiment. Either sawdust (SD, low biodegradability) or rice bran (RB, high biodegradability) was mixed with cattle manure at a various rate. Emitted CO₂ and NH₃ were collected and periodically determined. Percentage of dry matter loss during the composting period was also calculated. The amount of CO₂ emitted was much higher in the RB treatment than in the SD treatment. Accordingly, % of dry matter loss ranged from 35.1~41.5% in the RB treatment and that from 18.7~22.6% in the SD treatment. Such pattern clearly showed that RB is more biodegradable than SD. During the early composting period up to 8 days, negligible amount of ammonia volatilization was detected in both treatment regardless of the amendments. No meaningful ammonia volatilization was detected in the SD treatment until the end of composting. In the RB treatment, however, significant amount of ammonia volatilization was observed thereafter. Such differences could be attributed to the different properties of SD and RB. For example, the high C/N ratio of SD could enhance NH₄ ⁺ immobilization and thus decrease NH₄ ⁺ concentration that is susceptible to ammonia volatilization. Binding of NH₄ ⁺ on to phenolic compounds of SD may also contribute to the decrease in NH4 + concentration. Meanwhile, as RB has a relatively low C/N ratio, remineralization of immobilized NH₄ ⁺ could increase NH₄ ⁺ concentration as high as the level for the occurrence of ammonia volatilization.

『漂海錄』를 통해본 崔溥의 한국 고대사 인식

임상선(LIM, Sang-Sun) 한국사학사학회 2013 韓國史學史學報 Vol.0 No.28

The contents about ancient history of Korea recorded in the book 『Pyohaerok(漂海錄)』was reviewed around Choi Bu's discourse and his historic discussion appeared in his book 『Don-Guk Tong-Gam(東國通鑑)』. In the book 『Pyohaerok(漂海錄)』, many contents about Joseon's history and its chronicle were described. Choi Bu recognized ancient history of Korea was led from Dangun Age, Gija Joseon Dynasty, and Wiman Joseon Dynasty to the Three Hans and then the Three Kingdoms in order. In his book 『Don-Guk Tong-Gam(東國通鑑)』, Choi Bu insisted that the key secrete enabling the two kingdoms of Baekjae and Goguryeo existed for several hundreds and a thousand for Shilla, respectively was because of the three nations' founders soundly established the foundations of their nations, and summarized and evaluated the national chronicles of Baekjae, Shilla and Goguryeo by each king in each nation. Officials and scholars in Chinese Ming Dynasty wondered how Goguryeo repelled Chinese Tang Dynasty's military attacks. Choi Bu explained the success secrets were Goguryeo soldiers' faithfulness and the leaders and the soldiers' mutual trust and belief, but the ruling class including Joseon Kings at the time when he lived considered because Goguryeo had defended its castles well with relying on its mountain fortresses, it could had defeated the Tang's invasion attack. 『漂海錄』에 나타난 한국 고대사와 관련된 내용을 崔溥의 대화 내용과 그가 집필한 『東國通鑑』의 史論을 중심으로 검토하였다. 『표해록』에는 朝鮮의 歷史, 沿革에 대한 내용이 많이 기술되어 있다. 최부는 우리의 고대사가 檀君, 箕子, 衛滿에 이어 三韓, 그리고 三國으로 연결되는 것으로 인식하고 있다. 조선 연혁의 시작이 중국의 堯 시대와 같은 단군으로부터 시작되었다고 명나라 사람들에게 분명히 말하였다. 三國 중에서 처음 나라를 세운 것은 新羅이고, 이어서 高句麗ㆍ百濟가 일어나 조선의 땅이 세 부분으로 나뉘게 되었다고 보았다. 삼국에 대한 최부의 인식을 그가 작성한 『東國通鑑』의 史論을 통해 살펴본 바, 최부는 삼국이 각각 몇 백년, 천년을 이어간 것은 각국의 始祖들이 여러 어려움 속에서 나라의 기틀을 튼튼히 한 것이라 기술하고, 백제, 신라, 고구려의 연혁을 각국의 왕별로 정리, 평가하였다. 신라의 경우, 敬順王이 목숨을 바칠 생각은 하지 않고 하루 아침에 항복하여 나라가 망하였다며 애석해 하였는데, 이것은 『三國史記』의 저자 金富軾이 경순왕의 高麗 귀순을 높이 평가한 것과는 대조적인 것이다. 이와 같은 양자의 경순왕에 대한 평가 차이는 각자가 처한 시대적 상황이 다르기 때문이라고 할 수 있다. 明나라 인사들이 조선 역사에서 가장 관심을 가진 것은 高句麗였다. 중국 역사에서 최고 전성기의 하나였던 唐나라의 공격을 고구려가 어떻게 막아낼 수 있었는지를 다수의 명나라 사람들이 질문하였다. 최부는 고구려의 군사들이 도리가 있고, 상하간에 신의와 믿음이 있었기 때문에 공격을 막을 수 있었으나, 淵蓋蘇文이 죄가 있기 때문에 당 太宗의 토벌은 정당한 것이라고 평가하였다. 최부의 답변은 당시 조선의 위정자들이 갖고 있던 생각과는 차이가 난다. 즉, 조선의 왕을 비롯한 지배층은 고구려가 山城에 의지하여 성을 잘 지키기 때문이라고 생각하였고, 심지어 당 太宗의 安市城 공격을 잘 막았기 때문에 고구려가 망하지 않았다고 여기고 있었다. 이와 같이, 고구려가 唐을 물리친 원인을 당시 조선의 위정자들은 산성 축조와 이를 근거로 한 방어술이라는 실제적인 현상에서 찾고 있는 반면, 최부는 君臣간의 협력이라는 性理學的 입장에서 그 해답을 찾고 있다. 또한 최부와 명나라 인사들은 遼東 지역이 옛 고구려의 땅이고, 옛날의 고구려를 계승한 것이 지금의 朝鮮이라 인식하고 있었다.

이화학성이 상이한 가축분퇴비가 시용된 인셉티솔, 울티솔, 안디솔 토양의 질소 및 인 방출 포텐셜

임상선 ( Sang-sun Lim ),이선일 ( Sun-il Lee ),박현정 ( Hyun-jung Park ),이동석 ( Dong-suk Lee ),곽진협 ( Jin-hyeob Kwak ),최우정 ( Woo-jung Choi ) 한국농공학회 2009 한국농공학회 학술대회초록집 Vol.2009 No.-

Interactive effect of composts and soils that have different characteristics on N and P releasing potentials of compost-amended soils were examined through a 19-wk leaching experiment using seven composts and three soils (Inceptisol, Ultisol, and Andisol). Availability of indigenous N soils was revealed as the primary soil factor affecting N releasing potential. Only total N concentration of composts were positively correlated with the amount of N in leachates from compost-amended soils consistently across three soils, suggesting that it can better serve as a predictor of N availability in soils treated with composts than other variables such as mineral N. Mineral N (NH₄⁺+NO₃ ^-) concentration of composts was shown to be a possible proxy for N availability of compost-amended soils (Inceptisol and Andisol) with a relatively low immobilization potential. It was also proven that C/N ratio of compost needs to be considered for prediction of N (particularly NH⁴⁺) availability of compost-amended soils. Ultisol with higher available soil P than Inceptisol and Andisol showed the greatest amount of total P in leachates from the compost-amended soils. In Inceptisol and Ultisol, total P concentration of composts was positively correlated with total P amount in leachates from the compost-amended soils. However such a relationship was not found in Andisol which has a high P sorption capacity, suggesting that total P concentration of composts maybe successfully used in predicting P releasing potential of composts in soils with a low P sorption potential but not for soils with a high P sorption potential. Therefore, it is suggested that initial soil N availability and total N concentration and C/N ratio of compost should be considered to predict N availability of compost-amended soils and initial soil P availability and P sorption capacity, and total P concentration of composts for P availability prediction. (This study was supported by the Technology Development Program for Agriculture and Forestry, Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea)