• 제목/요약/키워드: Cropland

검색결과 125건 처리시간 0.022초

북한 산림의 시·공간 변화와 황폐화 추동 (Spatio-Temporal Changes and Drivers of Deforestation and Forest Degradation in North Korea)

  • 유재심;김경민
    • 한국환경복원기술학회지
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    • 제18권6호
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    • pp.73-83
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    • 2015
  • The objective of this study is to establish implications for forest restoration planning in North Korea by analyzing spatio-temporal forest changes and detecting bio-physical factors driving forest degraded. We measured the relationship and spatial distribution between shifting cultivation and sparse forest. We also analyzed between degraded forest land and ecological variables by binary logistic regression to find biophysical drivers of forest degradation and deforestation in North Korea. Between the sparse forest and the shifting cultivation, a positive relationship is found (r=0.91) and scattered discontinuously throughout the country (Moran's I = -1, Z score = -13.46 (p=0.000)). The sparse forest showed a negative relationship with the warmest month(bio 9), the coldest month(bio10), and the minimum of soil water contents (swc_min), while the shifting cultivation had a negative relationship with the warmest month(bio 9) and the minimum of soil water contents(swc_min). However, the most critical drivers convert forests into sloping farmland were the three months rainfall in summer(bio8) and the yearly mean of soil water contents. Such results reflect the growth period of crops which overlaps with the rainy season in North Korea and the recent land reclamation of uplands where the soil water contents are maintained with a dense forest. When South Korea aids forest restoration projects in North Korea, in consideration of food shortage due to North Korea's cropland deficiency, terrace farmlands where soil water contents can be maintained should be excluded from the priority restoration area. In addition, an evaluation method for selecting a potential restoration area must be modified and applied based on multiple criteria including altitude and socio-economic factors in the respective regions.

계절별 위성자료를 이용한 미국 캔자스주 식생 분류 - 하이브리드 접근방식의 적용 - (Kansas Vegetation Mapping Using Multi-Temporal Remote Sensing Data: A Hybrid Approach)

  • 박선엽
    • 대한지리학회지
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    • 제38권5호
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    • pp.667-685
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    • 2003
  • 미국 캔자스주 정부와 연방정부가 필요로 하는 상세한 지표피복 수치지도제작을 위해, Landsat Thematic Mapper 자료를 이용하여 캔자스주 전체를 대상으로 43가지로 분류된 식생군단(vegetation alliance) 수준의 자연식 생지도를 제작하였다. 지도제작 방법으로는 봄, 여름, 가을의 계절별 위성자료를 이용하여 두 단계 분류절차를 거치는 이른바 '하이브리드(hybrid)' 방식을 채택하였다. 이 접근 방법은 첫 단계로 unsupervised classification을 이용, 자연녹지를 농경지로부터 분리해 낸 다음. 두 번째 단계에서 supervised classification, 현장확인조사. 그리고 분류 후 다양한 보강자료를 이용하여 최종적으로 자연식생을 구분ㆍ분류해 내는 것이다. 정확도 평가는 세 가지 분류 수준에서 실행되었는데, 이는 앤더슨 분류단계 I(Anderson level I), 식생군계(vegetation formation), 그리고 식생군단 수준을 포함한다. 확인결과 전반적인 정확도는 51.7%에서 89.4%에 이르는 것으로 조사되었다.

Nutrient production from Korean poultry and loading estimations for cropland

  • Won, Seunggun;Ahmed, Naveed;You, Byung-Gu;Shim, Soomin;Kim, Seung-Su;Ra, Changsix
    • Journal of Animal Science and Technology
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    • 제60권2호
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    • pp.3.1-3.9
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    • 2018
  • Background: Poultry breeding has increased by 306% in Korea, inevitably increasing the production of manure which may contribute to environmental pollution. The nutrients (NP) in the manure are essential for crop cultivation and soil fertility when applied as compost. Excess nutrients from manure can be accumulated on the land and can lead to eutrophication. Therefore, a nutrient load on the finite land should be calculated. Methods: This study calculates the nutrient production from Korean poultry by investigating 11 broiler and 16 laying hen farms. The broiler manure was composted using deep litter composting while for layer deep litter composting, drying, and simple static pile were in practice. The effect of weight reduction and storing period during composting was checked. Three weight reduction cases of compost were constructed to calculate nutrient loading coefficients (NLCs) using data from; i) farm investigation, ii) theoretical P changes (${\Delta}P=0$), and iii) dry basis. Results: During farm investigation of broiler and layer with deep litter composting, there was a 68 and 21% N loss whereas 77 and 33% P loss was found, respectively. In case of layer composting, a loss of 10-56% N and a 52% P loss was observed. Drying manure increased the P concentrations therefore NLCs calculated using dry basis that showed quite higher reductions (67% N; 53% P). Nutrient loss from farm investigation was much higher than reported by Korean Ministry of Environment (ME). Conclusions: Nutrients in manure are decreased when undergo storing or composting process due to microbial action, drying, and leaching. The nutrient load applied to soil is less than the fresh manure, hence the livestock manure management and conservation of environment would be facilitated.

Investigating the Impact of Best Management Practices on Nonpoint Source Pollution from Agricultural Lands

  • 최예환
    • 한국농공학회지
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    • 제32권E호
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    • pp.1-19
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    • 1990
  • Abstract Over the last several decades, crop production in the United States increased largely due to the extensive use of animal waste and fertilizers as plant nutrient supplements, and pesticides for crops pests and weed control. Without the application of animal waste best management, the use of animal waste can result in nonpoint source pollution from agricultural land area. In order to increase nutrient levels and decrease contamination from agricultural lands, nonpoint source pollution is responsible for water quality degradation. Nonpoint source pollutants such as animal waste, ferilizers, and pesticides are transported primarily through runoff from agricultural areas. Nutrients, primarily nitrogen and phosphorus, can be a major water quality problem because they cause eutrophic algae growth. In 1985, it was presented that Watershed/Water Quality Monitoring for Evaluation BMP Effectiveness was implemented for Nomini Creek Watershed, located in Westmoreland County, Virginia. The watershed is predominantly agricultural and has an aerial extent of 1505 ha of land, with 43% under cropland, 54% under woodland, and 3% as homestead and roads. Rainfall data was collected at the watershed from raingages located at sites PNI through PN 7. Streams at stations QN I and QN2 were being measured with V-notch weirs. Water levels at the stream was measured using an FW-l Belfort (Friez FWl). The water quality monitoring system was designed to provide comprehensive assessment of the quality of storm runoff and baseflow as influenced by changes in landuse, agronomic, and cultural practices ill the watershed. As this study was concerned with the Nomini Creek Watershed, the separation of storm runoff and baseflow measured at QNI and QN2 was given by the master depletion curve method, and the loadings of baseflow and storm runoff for TN (Total Nitrogen) and TP (Total Phosphorus) were analyzed from 1987 through 1989. The results were studied for the best management practices to reduce contamination and loss of nutrients, (e.g., total nitrogen and total phosphorus) by nonpoint source pollution from agricultural lands.

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시용된 유기물 종류별 토양중 질소무기화 (Nitrogen Mineralization in Soils Added with Different Organic Materials)

  • 이종식
    • 한국토양비료학회지
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    • 제31권3호
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    • pp.233-237
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    • 1998
  • 토양에 시용되는 각종 폐유기물들의 토양중 질소 무기화율을 알아보기 위하여 3종의 폐유기물(A:도시고형폐기물+하수슬러지, B:목재잔사, C:목재잔사+하수슬러지)를 토양에 처리한 뒤 12주 동안 $25^{\circ}C$ 호기조건에서 질소 무기화율을 조사한 결과, 초기 질산화율은 C 처리구가 다른 처리구에 비하여 높았다. 또한 무기화된 총질소량은 C 처리구에서 가장 많았으나 실험기간 동안의 질소 무기화율과 질산화율은 무처리구에서 높게 나타났다.

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The effect of liquid swine manure application rate on the production of green manure crops in paddy

  • Choi, Jong-Seo;Kim, Sook-Jin;Kang, Shingu;Park, Jeong Hwa;Yoon, Young-Hwan;Yang, Woonho
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.209-209
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    • 2017
  • The application of liquid swine manure to soil has been commonly reported to increase crop productivity by improving plant nutrient availability. This study was conducted to investigate the effect of liquid swine manure (LSM) application on yield of green manure crops in paddy. Three different application rates of LSM equivalent to 25%, 50%, and 75% of standard fertilization rate of P were applied to the paddy field after rice harvest, and two cover crops, hairy vetch (Vicia villosa Roth) and barley (Hordeum vulgare L.), were subsequently mix-seeded and cultivated. Plant height of barley was 7% higher in LSM P25% and LSM P50% compared to control treatment (no LSM application), while no significant difference was observed between LSM P75% and control. However, there were no significant differences in plant height of hairy vetch among treatments. Dry matter (DM) yield of green manure increased with LSM application rate, reaching a maximum at LSM P50% (38 and 17% yield increase over control for hairy vetch and barley, respectively), but it decreased at LSM P75% rate. Nitrogen production by green manure crops was the highest in LSM P50% treatment, where the amount of produced N was 57% higher than the optimum N fertilization level for rice ($90kg\;N\;ha^{-1}$). Excess green manure biomass above an optimum level can be removed and utilized either for incorporation into nearby cropland or for sale as fresh forage. Therefore, it is concluded that the application rate of LSM P50% is recommendable for the maximum biomass and nitrogen production from green manure crops in paddy.

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Simulation of Effects of Swine Manure Application Rates on Nitrate Concentration in Runoff, Indiana, USA

  • Lim, Kyoung-Jae;Engel, Bernard A.;Jeon, Ji-Hong;Jones, Don;Sutton, Alan L.;Ok, Yang-Sik;Kim, Ki-Sung;Choi, Joong-Dae
    • 한국환경농학회지
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    • 제28권1호
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    • pp.38-46
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    • 2009
  • Livestock manure is an important source of nutrients for crop production. However, farmers typically do not know the exact nutrient values for livestock manure. In many instances, manure has been viewed as a waste, and as a result it is applied close to the source resulting in over application of nutrients. Thus, the goal of nutrient application has often been applied to reduce the application expense rather than to maximize crop income. This results in wasted money and potentially negative impacts on water quality. Several livestock manure management scenarios were created based on agronomic nutrient requirements using the Utilization of Animal Manure as a Plant Nutrient (AMANURE) software to investigate water quality impacts with the National Agricultural Pesticide Risk Analysis (NAPRA) WWW modeling system. Application of manure at agronomic rates can result in high nitrate-nitrogen losses for some soil types, especially when applied in late fall. The application of manure at an agronomic rate does not necessarily equate to adequate water quality protection, and farmers must take care applying manure at agronomic rates, because nitrate-nitrogen loss potential varies spatially and temporarily. Nutrient loss probability maps for Indiana at 5%, 10%, 25%, and 50% values were created to demonstrate potential water quality impacts when livestock manure is applied to cropland at agronomic rates. The NAPRA WWW system coupled with AMANURE can be used to identify site-specific livestock manure management plans that are environmentally sound and agronomically appropriate.

대구 동천동 청동기시대 취락유적 출토 목질류 수종 분석 연구 (Study of the Species of Trees Used for Wooden Artifacts Excavated from a Bronze-Age Settlement Site in Dongcheon-dong, Daegu)

  • 이효선
    • 박물관보존과학
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    • 제20권
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    • pp.49-60
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    • 2018
  • 대구 칠곡지구 일대 유적은 청동기시대 및 삼국시대 대규모 취락지가 확인된 고고학적 조사로 그 의의가 크다. 특히 대구 동천동 취락유적에서는 청동기시대 수혈주거지, 고상건물지, 석관묘, 우물, 집수기, 집석, 구상유구, 경작지, 환호, 하도 등의 유구가 확인되어 청동기시대 당시 취락의 전모를 알 수 있는 많은 자료가 조사되었다. 본 조사는 대구 동천동 취락유적 내 청동기시대 하도 유구 출토 목기 8점에 대한 수종분석 결과이다. 조사 결과, 침엽수재 수종인 소나무류(Pinus spp.)가 2점, 전나무속(Abies spp.) 수종이 2점, 활엽수재 수종인 상수리나무류(Quercus sp.)가 4점 식별되었다. 용도미상으로 분류된 3점의 목기는 소나무류와 전나무속 수종이였으며, 건축부재 5점은 소나무류가 1점, 상수리나무류가 4점이었다.

월악산국립공원의 현존식생 및 관리 (Actual Vegetation and Management in the Woraksan National Park)

  • 오구균;박상규;심항용;김태환
    • 한국환경생태학회지
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    • 제19권2호
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    • pp.119-129
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    • 2005
  • 월악산국립공원의 현존식 생 및 녹지자연도와 조경수목 식재현황을 2004년에 조사하였다. 월악산국립공원의 현존식 생은 총 12개의 식물군락과 기타지역으로 구분되었으며, 신갈나무군락, 소나무군락, 낙엽활엽수림, 침활혼효림 등 자연림은 8개 군락으로, 일본잎갈나무림, 잣나무림 등 인공림은 3개 산림유형으로 구분되었다. 조사지역의 녹지자연도는 8등급 지역이 약$73.08\%$로 가장 넓게 분포하였고, 9등급 지역이 약$11.32\%$로 나타났다. 조사지역의 조경수목 식재현황은 총 44과 129종류가 확인되었으며, 이 중 약 $65.65\%$가 외래종이었다.

Assessment of Sustainable Production on Paddy Field Treated with Green Manure Crops Using Sustainability Index

  • Kim, Kwang Seop;Kim, Sook-Jin;Park, Ki Do;Lee, Choon-Woo;Ryu, Jin-Hee;Choi, Jong-Seo;Jeon, Weon-Tai;Kang, Hang-Won;Kim, Min-Tae
    • 한국토양비료학회지
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    • 제47권3호
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    • pp.165-171
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    • 2014
  • Assessment of sustainable production on a cropland can help to determine the most proper management practices. In this study, we evaluated the sustainable production on paddy field treated with green manure crops using sustainability index which based on nutrient index, microbiological index, and crop index related to nutrient-supplying capacity. Especially choosing appropriate indicators from a minimum data set (MDS) were used the principal components analysis (SI-2) as well as expert opinion (SI-1) usually used in sustainability index. Six treatments including the two tillage treatments and two green manure crops were investigated as follows; (i) moldrotary + rotary tillage without green manure crop (Con), with (ii) hairy vetch (Con-HV), and (iii) hairy vetch + green barely (Con-HV+GB), (iv) rotary tillage without green manure crop (Rot), with (ii) hairy vetch (Rot-HV), and (iii) hairy vetch + green barly (Rot-HV+GB). Con-HV and Rot-HV in SI-1 were maintained sustainability while Rot-HV and Rot-HV+GB in SI-2. Especially, treatments (Con and Rot) without green manure crops were more unsustainable than with green manure crops because of the low value of microbiological and crop index than with green manure crops. Meanwhile, sustainability indices and grain yield had the high correlation values ($R^2=0.756$ and 0.928 in SI-1 and SI-2, respectively). These results meant that application of green manure crops such as hairy vetch could improve both yield and soil quality in paddy.