• Title/Summary/Keyword: soil quantity

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Influences of Mixing Frequency on the Composting Performance of the Broiler and Dairy Manure Mixtures (퇴비재료의 교반빈도가 육계분과 유우분 혼합물 퇴비화 성능에 미치는 영향)

  • Park K.J.;Bae Y.H.;Hong J.H.;Wi T.W.
    • Journal of Animal Environmental Science
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    • v.12 no.1
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    • pp.41-44
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    • 2006
  • Broiler manure has much nutrient that can be used as the organic fertilizer to enhance the fertility of soil. However, if it is used directly without biodegradation of organic materials and destruction of weed seed and harmful bacteria, it can produce the generation of weed and disease of plant. Composting of manure is a biodegradation of organic materials into inorganic materials and humus. To proceed biodegradation of manure effectively and enhance the composting performance, optimum environmental condition for microbial growing should be maintained. Environmental variables which can influence the growing activity of microbes are moisture content, pH, porosity, C/N of the composting materials and oxygen supply quantity. Oxygen and porosity are usually supplied by aeration or mixing of materials. This study was intended to investigate the effect of mixing frequency on the composting performance. Mixing of composting materials was performed by turning the bioreactor up and down by hand without any mechanical energy. The broiler manure was captured from the greenhouse type broiler ham as the compounds of broiler manure and rice-hulls, which were used as the base materials. To compost the compounds of broiler manure and rice-hulls, dairy manure was mixed to get appropriate characteristics of composting material. Composting temperature over $55^{\circ}C$ for killing pathogen and weed seed was maintained for longer period with increase of mixing frequency.

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Research on the Ground Water Developement in the Region of Choong Nam Province (충남지역의 지하수개발에 관한 조사)

  • 민병섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.11 no.4
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    • pp.1827-1831
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    • 1969
  • Resulties of research on the capacity of ground water of 994 concrete-pipe-wells and 97 infiltration-gallerys in ground-water-developement-works region executed from March to Julyin 1969, in Choong Chung Nam Do, and research on the quality of ground water for 88 wells for home-use around of River Geum Area, are as fellows: (1) Thickness of aquifer is no more than 2.85m averagely even at river-overflowed plain, alluvial plain and valley plain area that are estimated to contain ground water mostly. And so, it is guessed that ground water capacity is not much especially. (2) Soil of aquifer of the above area is sand or gravel and it is estimated to be good for ground water developement and its mean permeability coefficient is bout $2.5{\times}10^{-3}$(m/sec), and its porosity is about 33.9%. (3) The quality of ground water is good for irrigation water exception of delta plain area. Warm water plan is to need for irrigation water when water temperature is less than 19 degrees below zero. (4) Prospect of ground water developement, judging from quality and quantity, expects to lay infiltration gallery under the ground at river bed in order to utilize under-flow-water of river bed, river-overflowed plain, alluvial plain and valley plain that ground level is less than 50m. (5) Collectable water volume of under-flow-water of river bed is about 450 to $750m^3/day$ to be able to irrigate 3ha to 5ha of the cultivated land in case that infiltration gallery length is 50m and its depth is about 5m. (6) Collectable water volume at river-overflowed plain, alluvial plain and valley plain area, is estimated $150m^3/day$ to be able to irrigated 1ha of the cultivated land.

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On the Critical Relative Displacement between Pile Shaft and Surrounding Soil (말뚝주변 마찰력과 한계상대변위)

  • Kim, Myoung Mo;Shin, Eun Chul;Ko, Hon Yim
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.2
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    • pp.107-114
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    • 1989
  • Model pile pull-out tests have been executed to investigate the characteristics of the critical relative displacement at which the critical pile skin resistance is mobilized. Test result shows that the critical relative displacement is neither constant nor pile size dependent, but it is the most closely related with the magnitude of the critical skin resistance. The empirical relationship between the two quantities has been established. Behavior of centrifuge physical models of skin-resistance-related problems has been investigated on a quantitative basis by a computational method. A pile downdrag problem has been employed as an example of the skin-resistance-related problems. A simple transfer function type method has been developed for the analysis of the downdrag. It is concluded from the analysis that centrifuge physical modeling of skin-resistance-related problems may lead to an erroneous result on an unconservative side, as may have been expected due to the violation of the similarity rule by the quantity of the critical relative displacement.

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Assessing Climate Change Impacts on Hydrology and Water Quality using SWAT Model in the Mankyung Watershed (SWAT 모형을 이용한 기후변화에 따른 만경강 유역에서의 수문 및 수질 영향 평가)

  • Kim, Dong-Hyeon;Hwang, Syewoon;Jang, Taeil;So, Hyunchul
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.6
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    • pp.83-96
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    • 2018
  • The objective of this study was to estimate the climate change impact on water quantity and quality to Saemanguem watershed using SWAT (Soil and water assessment tool) model. The SWAT model was calibrated and validated using observed data from 2008 to 2017 for the study watershed. The $R^2$ (Determination coefficient), RMSE (Root mean square error), and NSE (Nash-sutcliffe efficiency coefficient) were used to evaluate the model performance. RCP scenario data were produced from 10 GCM (General circulation model) and all relevant grid data including the major observation points (Gusan, Jeonju, Buan, Jeongeup) were extracted. The systematic error evaluation of the GCM model outputs was performed as well. They showed various variations based on analysis of future climate change effects. In future periods, the MIROC5 model showed the maximum values and the CMCC-CM model presented the minimum values in the climate data. Increasing rainfall amount was from 180mm to 250mm and increasing temperature value ranged from 1.7 to $5.9^{\circ}C$, respectively, compared with the baseline (2006~2017) in 10 GCM model outputs. The future 2030s and 2070s runoff showed increasing rate of 16~29% under future climate data. The future rate of change for T-N (Total nitrogen) and T-P (Total phosphorus) loads presented from -26 to +0.13% and from +5 to 47%, respectively. The hydrologic cycle and water quality from the Saemanguem headwater were very sensitive to projected climate change scenarios so that GCM model should be carefully selected for the purpose of use and the tendency analysis of GCM model are needed if necessary.

The Energy Flow and Mineral Cycles in a Zoysia japonica and a Miscanthus sinensis Ecosystem on Mt. Kwanak 6. The Cycles of Ca, Mg, Na (관악산의 잔디와 억새 생태계에 있어서 에너지의 흐름과 무기물의 순환 6.Ca,Ma,Na의 순환)

  • 김정석;장남기
    • Asian Journal of Turfgrass Science
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    • v.10 no.2
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    • pp.105-115
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    • 1996
  • To find out the mineral cycles of calcium, magnesium and sodium in dynamic grassland cosystems in a steady state condition, this investigation was conducted along the northwest side on Mt. Kwanak. The experimental results may he suromarized on the communities of a Zoysia japonica and a Miscanthus sinesis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, cal- cium (Ca) was greater quantity in a Zoysia japonica, whereas, in a Miscanthus sicensis, sodium (Na)and magnesium (Mg) were greater in Mt. Kwanak. For the case of steady production and release, the ratio of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants of Ca, Mg and Na of the litter were 0.42, 0.25 and 0.29 in the Zoysia japonica grassland, and were 0.41, 0.54 arid 0.62 in the Miscanthus sinensis grassland, respect- ively. The half times of Ca, Mg and Na required for the release or accumulation of the litter on the grassland were 1.65, 2.77 and 2.39 in the Zoysia japonica, and were 1.69, 1.28 and 1.12 in the Miscauthus sinensis, respectively. The increasing order of the turnover parameters of the elements was Ca, Na and Mg in the Zoysia japonica grassland, and was Na, Mg and Ca in the Miscanthus Si nens is grassland. The amounts of annual cycles for Ca, Mg, Na in the grassland ecosystem under the steady-state conditions were 1.29, 0.20 and 0.12 g /m$^2$ in the Zoysia japonica grassland and 3.91, 1.04 and 0.61 g /m$^2$ in the Miscanthus sinensis grassland.

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The Characteristics of the Discharge Lamp Type Ozonizer using Pulse Power Source for Carnation Productivity Improvement (카네이션 생산성 향상을 위한 펄스 전원을 활용한 방전관형 오존발생기의 특성)

  • Song, Hyun-Jig
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.7
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    • pp.68-74
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    • 2007
  • For carnation productivity improvement, compact-low cost discharge lamp type ozonizer using pulse power source is designed and manufactured. This paper describes the discharge characteristics and the ozone generation characteristics with variation of the output voltage of pulse power source, the quantity of flowing air and the operating number of ozonizer. The important conclusions are as follows. The discharge voltage and current values are proportional to the output voltage of pulse power source. The ozone concentration and generation are proportional to the output voltage of pulse power source and the number of ozonizer. The maximum value of the ozone concentration and generation of the discharge lamp type ozonizer can be obtained 890[ppm] and 59.7[mg/h] respectively. In the carnation productivity house, when the discharge lamp type ozonizer is used the carnation is good quality in the uniformity of the carnation stalk thickness and increased the productivity through improvement of the air and the soil.

Evaluation of the Impacts of Water Quality Management in Kyongan Stream Watershed using SWAT Model (SWAT 모델을 이용한 경안천 유역의 수질관리 영향 평가)

  • Jang, Jae-Ho;Yoon, Chun-Gyeong;Jung, Kwang-Wook;Kim, Hyung-Chul
    • Journal of Korean Society on Water Environment
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    • v.26 no.3
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    • pp.387-398
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    • 2010
  • SWAT model would be applied to evaluate the pollutant removal capacity with various best management practices (BMPs) in Kyongan stream watershed which plays an important role in water quality conservation and improvement of Paldang reservoir. The methods for the representation of various BMPs scenarios with SWAT is developed and evaluated. Riparian buffer strip, agricultural conservation practices to reduce fertilizer, sediment, and nutrients occurring from farm field (Grassed swale, Contour farming/Parallel terrace, Field border, Farm retention pond, Grade stabilization structure), and washland such as wetland and pond to extend detention and improve water quality are represented in SWAT. And to represent the expansion of existing Waste Water Treatment Plants (WWTPs) in Soil and Water Assessment Tool (SWAT), reduction effect for point source pollutants was simulated. As the result of simulation, the removal rates of SS, TN, TP from scenarios of Kyongan stream watershed are the average annual SS yield by 5.2% to 69.2%, the average annual TN yield by 0.5% to 26.3%, and the average annual TP yield by 1.3% to 32.5%, respectively. This study has demonstrated that the SWAT is a very reliable and useful water quality and quantity assessment tool, and the BMPs representation in SWAT for watershed management is able to effectively simulate in Kyongan Stream watershed.

Importance and production of chilli pepper; heat tolerance and efficient nutrient use under climate change conditions

  • Khaitov, Botir;Umurzokov, Mirjalol;Cho, Kwang-Min;Lee, Ye-Jin;Park, Kee Woong;Sung, JwaKyung
    • Korean Journal of Agricultural Science
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    • v.46 no.4
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    • pp.769-779
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    • 2019
  • Chilli peppers are predominantly cultivated in open field systems under abiotic and biotic stress conditions. Abiotic and biotic factors have a considerable effect on plant performance, fruit quantity, and quality. Chilli peppers grow well in a tropical climate due to their adaptation to warm and humid regions with temperatures ranging from 18 to 30℃. Nowadays, chilli peppers are cultivated all around the world under different climatic conditions, and their production is gradually expanding. Expected climate changes will likely cause huge and complex ecological consequences; high temperature, heavy rainfall, and drought have adverse effects on the vegetative and generative development of all agricultural crops including chilli peppers. To gain better insight into the effect of climate change, the growth, photosynthetic traits, morphological and physiological characteristics, yield, and fruit parameters of chilli peppers need to be studied under simulated climate change conditions. Moreover, it is important to develop alternative agrotechnologies to maintain the sustainability of pepper production. There are many conceivable ideas and concepts to sustain crop production under the extreme conditions of future climate change scenarios. Therefore, this review provides an overview of the adverse impacts of climate change and discusses how to find the best solutions to obtain a stable chilli pepper yield.

Estimation and Reduction of Downdrag Force (부주변 마찰력과 그 감소방법의 평가)

  • Im, Jong-Seok;Kim, Myeong-Mo;Jeong, In-Jun
    • Geotechnical Engineering
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    • v.3 no.1
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    • pp.39-52
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    • 1987
  • Model pile tests are performed, first, to estimate donwndrag exerted on pile surfaces due to the settlement of surrounding soils, and, second, to evaluate the efficiency of the downdrag reduction methods such as the bitumen coating method and the method of the attachment of an enlarged base. Test results show that the downdrag forces may be expressed as 0.25(;effective overburden). Bitumen coating reduces the downdrag by more than 50 percent, and the enlarged base attachment method is also effective, whose effectiveness increases as the sixte of the base increases as expected. When the bitumen coating and enlarged base are both applied, the downdrag force is reduced as much as 90 percent. Finally, it is found that the quantity of the relative displacement between the pile and the surrounding soil downdrag is extremely small.

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Fundamental Studies on Stabilization of Shallow Slope Failure Using Lime Pile - Changes of Clayey Properties with Lime Addition - (생석회 파일을 이용한 얕은 사면 파괴의 안정화에 대한 기초 연구 - 생석회 첨가에 따른 점성토의 특성 변화 중심으로 -)

  • Kwon, Moonam;Goo, Jeungmin
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.5
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    • pp.49-55
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    • 2006
  • Quick lime made from limestone that are deposited abundantly in Korea has excellent potentials for stabilization of clayey soils. If Korea is able to take advantage of its abundant supply, economical efficiency could be achieved through mass production as well as being able to take advantage of utilization of natural resources. For stabilizing of clayey soil with lime, it is necessary to determine the required quantities of lime firstly and to evaluate the degree of stabilization with lime content. In this test, the quantity of lime required for 2 clayey soils which located in Seunggok and Bugok province respectively, and for 2 clay minerals-kaolinite and montmorillonite-were determined by ASTM C 977-92 and were evaluated for solidification of each samples with changing lime contents by Atterberg limit test and pH test. It was also evaluated for the improvement of each sample with lime content and curing time. The sample which added lime content determined by ASTM C 977-92 increased plastic limit, unconfined compression strength, and decreased pH in increasing trend.

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