• 제목/요약/키워드: over nutrients

검색결과 608건 처리시간 0.025초

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.

The optimal balance between sexual and asexual reproduction in variable environments: a systematic review

  • Yang, Yun Young;Kim, Jae Geun
    • Journal of Ecology and Environment
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    • 제40권2호
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    • pp.89-106
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    • 2016
  • Many plant species have two modes of reproduction: sexual and asexual. Both modes of reproduction have often been viewed as adaptations to temporally or spatially variable environments. The plant should adjust partitioning to match changes in the estimated success of the two reproductive modes. Perennial plants showed that favorable habitats in soil nutrients or water content tend to promote clonal growth over sexual reproduction. In contrast, under high light-quantity conditions, clonal plants tend to allocate more biomass to sexual reproduction and less to clonal propagation. On the other hand, plants with chasmogamous and cleistogamous flowers provides with a greater tendency of the opportunity to ensure some seed set in any stressful environmental conditions such as low light, low soil nutrients, or low soil moisture. It is considered that vegetative reproduction has high competitive ability and is the major means to expand established population of perennial plants, whereas cleistogamous reproduction is insurance to persist in stressful sites due to being strong. Chasmogamous reproduction mainly enhances established and new population. Therefore, the functions of sexual and asexual propagules of perennial or annual plants differ from each other. These traits of propagule thus determine its success at a particular region of any environmental gradients. Eventually, if environmental resources or stress levels change in either space or time, species composition will probably also change. The reason based on which the plants differ with respect to favored reproduction modes in each environmental condition, may be involved in their specific realized niche.

행암만 해양환경요인과 플랑크톤 군집구조의 변동 (Plankton Community Composition Related to Marine Environmental Factors in Haengam Bay)

  • 김정배;홍석진;이원찬;김형철;이용우;윤석현;조윤식
    • 한국환경과학회지
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    • 제23권12호
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    • pp.2015-2028
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    • 2014
  • We analyzed with HPLC (High Performance Liquid Chromatography) analysis photosynthetic pigments and environmental factors, microscopic observations of the phytoplankton and zooplankton in the seawater every month from February 2009 to November 2010 in Haengam Bay. The level of dissolved inorganic nutrients was the highest between July and September, when freshwater influx was at its peak, whereas chlorophyll a levels were the highest in April and August. Also, phytoplankton pigment concentration increased when dissolved inorganic nutrients are carried into nearshore waters by rainfall runoff. Based on identification of phytoplankton and photosynthetic pigments results, diatoms were mainly dominant while dinoflagellate populations increased at July and August 2009, May 2010. The zooplankton communities are dominated in terms of Noctiluca scintillans. The contribution of Noctiluca scintillans in 2010 accounts for approximately 77.3% of the total zooplankton. Distribution patterns over time of zooplankton in the seasonal distribution of phytoplankton showed a different pattern.

한국성인의 비만유형에 따른 식사의 질과 다양성 비교 (Comparison of Diet Quality and Diversity according to Obesity Type among 19-64 year old Korean Adults)

  • 구혜민;류소연;박종;한미아;손영은
    • 대한지역사회영양학회지
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    • 제21권6호
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    • pp.545-557
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    • 2016
  • Objectives: This study was performed to compare the diet quality and diversity according to types of obesity categorized by body mass index and waist circumference among Korean adults aged 19-64 years. Methods: This study used the data of the 5th Korea National Health and Nutrition Examination Survey (KNHANES-V) and included 11,081 study participants. Type of obesity was categorized into 4 groups (Type 1: BMI obesity + abdominal obesity; Type 2: BMI obesity only; Type 3: abdominal obesity only; Type 4: Normal). To compare the diet quality and diversity according to obesity type, ANCOVA (Analysis of covariance) was used with stratification of age groups (19-44 years, 45-64 years). Results: With regard to comparative analysis of diet quality, there were significant differences between diet qualities in energy, protein, thiamin, riboflavin, niacin, phosphorous and iron and type of obesity in the 19-44 age group, while there were significant differences between diet qualities on protein, vitamin C, phosphorous and type of obesity in the 45-64 age group. There was no significant difference between diet diversity score and type of obesity in Korean adults. Conclusions: This study showed that in Korean adults, diet qualities of some nutrients were different among obesity types, while diet diversity was not. These observations should be considered in an effort to improve intake of over-and deficient nutrients and in further studies to evaluate the effects of nutrient quality on obesity.

경기 일부지역 노인복지관 제공 무료 급식의 나트륨 등 영양소 함량에 관한 조사 (Sodium Content and Nutrients Supply from Free Lunch Meals Served by Welfare Facilities for the Elderly in Gyeonggi-do)

  • 박서연;안소현;김진남;김혜경
    • 한국식품영양학회지
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    • 제26권3호
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    • pp.459-469
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    • 2013
  • This study was performed to estimate the salt content and evaluate the nutritional quality of free lunch meals served by welfare facilities for the elderly. We collected food items from 8 welfare facilities in Gyeonggi-do, and calculated the total salt content from the salinity and weight of individual food items. The average salt content from lunch meals was 5.68 g, which was over the recommended daily salt intake by the WHO. The greatest contributor to the salt content among the menu groups was soup and stew (37.5%). Soup, stew, deep-fried foods, and sauces were major sources of salt, while the most salty dishes were sauces, deep-fried food, salt-fermented food, and kimchi. The nutrient content was sufficient, except for calcium in both men and women, which was equal to approximately 1/3 of the dietary recommended intakes (DRIs) for Korean adults of their mean age. In addition, the index of nutritional quality (INQ) and nutrient adequacy ratios (NAR) of most nutrients were satisfactory, except for those of calcium and sodium. The INQs of calcium and sodium were 0.64 and 4.41, respectively, while the mean adequacy ratio of a meal was 0.95. These results suggest that multilateral efforts to lower sodium intake be considered and calcium sources be added, in order to improve the quality of meals served to the elderly at welfare facilities.

Long-term Seasonal and Interannual Variability of Epilimnetic Nutrients (N, P), Chlorophyll-a, and Suspended Solids at the Dam Site of Yongdam Reservoir and Empirical Models

  • An, Kwang-Guk
    • 생태와환경
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    • 제44권2호
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    • pp.214-225
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    • 2011
  • The objectives of the study were to evaluate seasonal patterns of epilimnetic water quality, and determine interannual eutrophication patterns at the dam site of Yong-dam Reservoir using long-term data during 2002~2009. Ionic dilutions, based on specific conductivity, occurred in the summer period in response to the intense monsoon rain and inflow, and suspended solid analysis indicated that the reservoir was clear except for the monsoon. Seasonality of nitrogen contents varied depending on the types of nitrogen and responded to ionic dilution; Ammonia-nitrogen ($NH_4$-N) peaked at dry season but nitrate-nitrogen ($NO_3$-N) peaked in the monsoon when the ionic dilution occurred. The maxima of $NO_3$-N seemed to be related with external summer N-loading from the watershed and active nitrogen fixation of bluregreens in the summer. $NO_3$-N was major determinant (>50%) of the total nitrogen pool and relative proportion of $NH_4$-N was minor. Long-term annual $NO_3$-N and TDN showed continuous increasing trends from 2004 to 2009, whereas TP and TDP showed decreasing trends along with chlorophyll-a (CHL) values. Empirical model analysis of log-transformed nutrients and N : P ratios on the CHL showed that the reservoir CHL had a stronger linear function with TP ($R^2$=0.89, p<0.001) than TN ($R^2$=0.35, p=0.120). Overall results suggest that eutrophication progress, based on TP and CHL, is slow down over the study period and this was mainly due to reduced phosphorns, which is considered as primary nutrient by the empirical model.

동화습지의 갈대 침수줄기에 서식하는 부착규조군집의 생태학적 특성 (Periphytic Diatom Communities and Water Environment in the Donghwa Constructed Wetlands)

  • 김백호;박영석;김용재
    • 생태와환경
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    • 제43권1호
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    • pp.91-102
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    • 2010
  • 상을 차지하는 갈대의 침수줄기에 형성된 부착규조 군집 빛 수질특성을 파악하고자, 결빙기를 제외한 2005년 3월부터 10월까지 유입수, 습지(고습지, 저습지), 배출구를 각각 조사하여 다음과 같은 결과를 얻었다. 1) 습지에 상관없이 높은 유기물 및 영양염 지수를 나타냈으며, 습지를 통과하면서 질소계열은 감소한 반면, 인계열은 오히려 증가하였다. 2) 부착규조는 저온기에 보다 다양하고 높은 생물량을 나타냈으며, 우점종은 습지에 관계없이 Nitzschia palea, Nitzschia amphibia 였으며, 조사 시기(강우)에 따라 다양한 범위를 나타냈다 3) 저습지 보다 고습지에서 높은 현존량은 영양염과 광투과율, 그리고 낮은 canopy와 관계가 있는 것으로 판단되었다. 따라서 동화습지는 풍부한 퇴적물과 갈대 쇄설물로부터 유출된 영양물질(특히 인)이 특정 규조류의 성장을 촉진하였으며, 특히 갈대식물 밀도가 적어 낮은 canopy를 보였던 고습지에서 높은 현존량을 나타났다.

유체 흐름 안에서 두 종의 생물막 성장 시뮬레이션 모델 (Simulation Model of Dual-Species Biofilm Growth in Hydrodynamic Flow)

  • 전원주;이상희
    • 한국시뮬레이션학회논문지
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    • 제20권1호
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    • pp.97-105
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    • 2011
  • 하천에서, 생물막은 녹갈색의 얇은 막의 형태로 돌, 식물, 그리고 기타 구조물의 표면에 부착되어 있다. 생물막은 주로 영양물의 순환, 수질정화, 바닥 침전물 제거, 그리고 먹이사슬내의 에너지 흐름에 매우 중요한 역할을 한다. 본 연구에서, 우리는 유체 흐름 안에서, 독소-생산 종과 독소-민감 종의 복합적 생물막을 전산 모사하는 모델을 개발하였다. 유체 흐름으로는 균일한 흐름과 불 균일한 흐름 두 가지를 고려하였다. 균일한 흐름은 확률 프로세스로 구현되었으며, 불 균일한 흐름은 나비어-스톡스 방정식으로 구현되었다. 모델에서, 독소-생산종과 독소-민감종 간의 상호작용을 고려하기 위해, 종 개체의 번식률과 사망률이 고려되어졌다. 우리는 서로 다른 두 유체 흐름 내에서 전산 모사 되어진 생물막의 구조적 형상에 대해서 간략히 논의 하였다.

NSI Checklist에 의한 우리 나라 일부 노년기 여성의 건강위험도와 영양소 섭취량 및 아연영양상태와의 관련성 (Nutrients Intake, Zine Status and Health Risk Factors in Elderly Korean Women as Evaluated by the Nutrition Screening Inistiative (NSI) Checklist)

  • 윤진숙;이정현
    • 대한지역사회영양학회지
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    • 제7권4호
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    • pp.539-547
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    • 2002
  • The purpose of this study was to investigate whether the health status as determined by a self-assessment checklist was related to the nutritional status of elderly Korean women. We interviewed 59 female subjects living in the Daegu area aged over 55 years. Information on their dietary intake on two consecutive days was collected by the 24-hour Recall Method. Their body compositions were measured using a Bio-electrical Impedence Fatness Analyzer. Their zinc status was evaluated according to their dietary zinc intake and urinary zinc excretion in urine samples collected for 24 hours. Their heath status was determined by a NSI Checklist. While 50.9% of the total subjects belonged to a moderate nutritional risk group,23.7% of the subjects were at a high nutritional risk. It appeared that only 25.4% of the subjects were evaluated as being healthy. Therefore, the overall nutritional health status of the elderly females belonged to the moderate nutritional risk group. Except for vitamin C, the average daily nutrient intake of the subjects was below the level of the recommended dietary allowances (RDA) for Koreans. The lower the nutritional health score, the better was their dietary intake of energy (p<.05), protein (p<.001), and zinc (p<.01). A positive relationship between their nutritional health score and body fat ratio was also observed (p<.05). Therefore, we suggest that the NSI Checklist could be used as a practical screening tool at the beginning of nutritional surveillance of the elderly in the community.

학교영양사가 요구하는 영양교육 교재의 특성 (School Dietitians Need Useful Nutrition Counseling Materials)

  • 김창임;박영숙;이정원;현화진
    • 대한영양사협회학술지
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    • 제12권3호
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    • pp.243-253
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    • 2006
  • The purpose of this study was to investigate dietitians' needs of teaching materials about nutrition education for school children in Kyonggi and Chungnam(including Daejeon) areas. This study was carried out using questionnaires via e-mail or in class to the subjects of 166 elementary school dietitians as 68 in Kyonggi and 98 in Chungnam. The number of small(less than 700 meals), medium(700-1400 meals) and large(over 1400 meals) schools based on served meals daily were 48, 62 and 56, respectively. The results are as follows: Frequency of nutrition education for students as well as for teachers was samely very low as 'once per two months' and the education used to perform during lunch time mostly. For preparing nutrition education they obtained informations from the internet(64.0%). The main topics of nutrition education they used to covered were 'et's eat breakfast', 'table manners', 'the relations of body and nutrients', 'food waste', 'foods and calorie', etc.. The largest limit of nutrition education practices faced by school dietitians were pointed out as 'lacks of teaching materials' and 'counseling techniques'. Most dietitians wanted CD or substantial teaching materials for the practices, and required their contents covering 'cooking', 'food and calories', 'let’s eat various foods', 'relations of body and nutrients', 'regular meal is important’ and etc.. Since we expect nutrition teachers to be realized soon, nutrition education/counseling is emphasized more as their duty. Even though school dietitians revealed poor self-confidence, they were positive to get improved by reeducation of nutrition counseling methods and skills. If easy and suitable education materials(CD type) are developed as good as the school dietitians desired, the materials could contribute much to better nutrition education/counseling practices at schools.

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