• 제목/요약/키워드: SOIL BULK DENSITY

검색결과 382건 처리시간 0.023초

Hydraulic Property and Solute Breakthrough from Salt Accumulated Soils under Various Head Pressures

  • Lee, Sanghun;Chung, Doug-Young;Hwang, Seon-Woong;Lee, Kyeong-Bo;Yang, Chang-Hyu;Kim, Hong-Kyu
    • 한국토양비료학회지
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    • 제45권5호
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    • pp.717-724
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    • 2012
  • Salt accumulated soil should be reclaimed to lower salt level for crop production. This study was carried out to investigate the characteristics of water flow and transport of mono and divalent solutes on salt accumulated soils with different head pressures. Saturated hydraulic conductivity was measured by constant and falling head methods with maintaining different head pressures. Saturated hydraulic conductivity was influenced by bulk density and organic matter contents in soils, but it had different elusion patterns between saline and sodic soil. While the quantity of water necessary for reclamation could be varies with soil type, it was considered that the supply of one pore volume of water was affordable and economic. Additional head pressure significantly increased the volume of leachate at a given time and it was more effective at low organic matter soils. The results indicate that additional head pressure would be one of the best irrigation practices on desalination method for salt accumulated soils.

Performance of Zoysia spp. and Axonopus compressus Turf on Turf-Paver Complex under Simulated Traffic

  • Chin, Siew-Wai;Ow, Lai-Fern
    • Weed & Turfgrass Science
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    • 제5권2호
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    • pp.88-94
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    • 2016
  • Vehicular traffic on turf results in loss of green cover due to direct tearing of shoots and indirect long-term soil compaction. Protection of turfgrass crowns from wear could increase the ability of turf to recover from heavy traffic. Plastic turfpavers have been installed in trafficked areas to reduce soil compaction and to protect turfgrass crowns from wear. The objectives of this study were to evaluate traffic performance of turfgrasses (Zoysia matrella and Axonopus compressus) and soil mixture (high, medium and low sand mix) combinations on turf-paver complex. The traffic performance of turf and recovery was evaluated based on percent green cover determined by digital image analysis and spectral reflectance responses by NDVI-meter. Bulk density cores indicated significant increase in soil compaction from medium and low sand mixtures compared to high sand mixture. Higher reduction of percent green cover was observed from A. compressus (30-40%) than Z. matrella (10-20%) across soil mixtures. Both turf species displayed higher wear tolerance when established on higher sand (>50% sand) than low sand mixture. Positive turf recovery was also supported by complementary spectral responses. Establishment of Zoysia matrella turf on turfpaver complex using high sand mixture will result in improved wear tolerance.

Effect of Chemical Fertilizer and Compost on Soil Physicochemical Properties, Leaf Mineral Content, Yield and Fruit Quality of Red Pepper (Capsicum annuum L.) in Open Field

  • Lee, Seong Eun;Park, Jin Myeon;Park, Young Eun;Lim, Tae Jun
    • 한국토양비료학회지
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    • 제48권6호
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    • pp.683-688
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    • 2015
  • Nowadays, sustainable and environment-friendly agriculture has become an important issue all around the world, and repeated applications of mineral and/or organic fertilizer will probably affect mineral nutrient dynamics in soil in the long term but only a limited number of observations are available. This study was carried out to investigate whether there is any influence of different fertilizer management for red pepper (Capsicum annuum L.) cultivation on soil physicochemical properties, leaf mineral content, yield and fruit quality in the aspect of long-term practice in open field condition. NPK, NPK+compost, compost only, and unfertilized control plot were included in the treatments. The application of chemical fertilizer and/or compost repeated annually for 17 years from 1994 to 2011. Soil organic matter content was higher in compost treatments than in no-manure treatments. Available phosphate and the yield of red pepper were highest in NPK+compost treatment followed by NPK (chemical fertilizer), compost, and control. The results indicate that in the long term, nitrogen supply is still needed for increasing red pepper yield, but reduction in the use of chemical fertilizer could be also possible with the proper application of compost.

Estimation of Soil Organic Carbon Stock in South Korea

  • Thi, Tuyet-May Do;Le, Xuan-Hien;Van, Linh Nguyen;Yeon, Minho;Lee, Giha
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.159-159
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    • 2022
  • Soil represents a substantial component within the global carbon cycle and small changes in the SOC stock may result in large changes of atmospheric CO2 particularly over tens to hundreds of years. In this study, we aim to (i) evaluate the SOC stock in the topsoil 0 - 15 cm from soil physical and chemical characteristics and (ii) find the correlation of SOC and soil organic matter (SOM) for national-scale in South Korea. First of all, based on the characteristics of the soil to calculate the soil hydraulic properties, SOC stock is the SOC mass per unit area for a given depth. It depends on bulk density (BD-g/cm3), SOC content (%), the depth of topsoil (cm), and gravel content (%). Due to insufficient data on BD observation, we establish a correlation between BD and SOC content, sand content, clay content parameter. Next, we present linear and non-linear regression models of BD and the interrelationship between SOC and SOM using a linear regression model and determine the conversion factor for them, comparing with Van Bemmelen 1890's factor value for the country scale. The results obtained, helps managers come up with suitable solutions to conserve land resources.

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GIS를 활용한 도시공원 시공후 평가에 관한 연구 - 서울 중구 남산골공원을 중심으로 - (A Study on the Evalution after Urban Park Construction by Geographic Information System - Namsangol Park , Junggu , Seoul -)

  • 장동수;김남규
    • Spatial Information Research
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    • 제4권1호
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    • pp.93-105
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    • 1996
  • 본 연구의 목적은 GIS를 활용해 공원시공후 발생될 물리적.생태적 문제를 해결키 위해 현상태를 종합적으로 평가하고 그 개선방향을 제시하는데 있다. 따라서 본 연구는 남산골 제모습 찾기의 일환으로 남산의 원지형 복원을 시도한 남산골 공원을 대상으로 시공전후의 지형변경, 토양여건, 색생, 수문/기상 등을 조사 혹은 측정해 나타난 문제들을 GIS를 통해 분석하였다. 주요 조사항목은 지형(질성토지역, 경사도) 토양(pH, EC, 유기물, 보수력, 가비중, 공극율), 식생(식재상태, 식재밀도, 수종), 수문/기상(강우량, 배수 및 유역)등이며, 토양관련 중첩(토양+절성토, 토양+소나무)지형관련 중첩(절성토+식재밀도, 절성토+수종)등을 종합 분석하였다. 그 결과로서 현재 남산골 공원은 토양상태가 불량하여 공원개방 초기에 집중적이며 계획적인 관리가 되지 않으면 이식된 수목의 활착이 어려운 상태이다. 식생은 생태적 조성을 추구하면서도 상징적인 소나무를 집중식재하는 등의 문제가 나타났다. 이 문제의 해결방안으로는 능선부 관수시설의 도입, 유기물 시비와 같은 토양개선, 부분이지만 식생수종의 개량 등이 지적되었다.

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Changes of Soil Properties with Various Soil Amendments in Saemangeum Reclaimed Tidal Saline Soil

  • Lee, Sanghun;Kim, Hong-Kyu;Hwang, Seon-Woong;Lee, Kyeong-Bo
    • 한국토양비료학회지
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    • 제46권4호
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    • pp.281-287
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    • 2013
  • Due to its high salt content and poor physical properties in reclaimed tidal lands, it is important to ameliorate soil physical properties to improve the efficiency of desalination. The objective of this study was to evaluate the changes of soil properties at Saemangeum reclaimed tidal saline soil with various soil amendments. Field experiment was conducted at Saemangeum reclaimed tidal land in Korea and the dominant soil series was Munpo series (coarse loamy, mixed, nonacid, Mesic, Typic, Fluvaquents). Woodchips, crushed-stone, oyster shell, coal bottom ash, and rice hull were added as soil amendments and mixed into surface soil to improve soil physical properties. There was large variability in soil hardness, but oyster shell treatment was significantly lower soil hardness at surface layer. Soil hardness was not significantly different below 15 cm depth. Infiltration rate was also significantly greater at oyster shell treatment. This may be due to the leaching of Ca ions from oyster shell and improved soil properties. However, there was no statistical significant difference of the soil bulk density, moisture content, and porosity. Improved physical properties increased desalinization rate in soil and retarded the resalinization rate when evapotranspiration rate was high. Although soil salinity was significantly decreased with oyster shell amendment, soil pH was increased that should be made up as a soil amendment. Our results indicated that oyster shell application increased infiltration rate and improved soil hardness, and thus oyster shell could be used to improve soil salinity level at Saemangeum reclaimed tidal saline soil.

Effects of Long-Term Fertilizer Practices on Rhizosphere Soil Autotrophic CO2-Fixing Bacteria under Double Rice Ecosystem in Southern China

  • Tang, Haiming;Wen, Li;Shi, Lihong;Li, Chao;Cheng, Kaikai;Li, Weiyan;Xiao, Xiaoping
    • Journal of Microbiology and Biotechnology
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    • 제32권10호
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    • pp.1292-1298
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    • 2022
  • Soil autotrophic bacterial communities play a significant role in the soil carbon (C) cycle in paddy fields, but little is known about how rhizosphere soil microorganisms respond to different long-term (35 years) fertilization practices under double rice cropping ecosystems in southern China. Here, we investigated the variation characteristics of rhizosphere soil RubisCO gene cbbL in the double rice ecosystems of in southern China where such fertilization practices are used. For this experiment we set up the following fertilizer regime: without any fertilizer input as a control (CK), inorganic fertilizer (MF), straw returning (RF), and organic and inorganic fertilizer (OM). We found that abundances of cbbL, 16S rRNA genes and RubisCO activity in rhizosphere soil with OM, RF and MF treatments were significantly higher than that of CK treatment. The abundances of cbbL and 16S rRNA genes in rhizosphere soil with OM treatment were 5.46 and 3.64 times higher than that of CK treatment, respectively. Rhizosphere soil RubisCO activity with OM and RF treatments increased by 50.56 and 45.22%, compared to CK treatment. Shannon and Chao1 indices for rhizosphere soil cbbL libraries with RF and OM treatments increased by 44.28, 28.56, 29.60, and 23.13% compared to CK treatment. Rhizosphere soil cbbL sequences with MF, RF and OM treatments mainly belonged to Variovorax paradoxus, uncultured proteobacterium, Ralstonia pickettii, Thermononospora curvata, and Azoarcus sp.KH33C. Meanwhile, cbbL-carrying bacterial composition was obviously influenced by soil bulk density, rhizosphere soil dissolved organic C, soil organic C, and microbial biomass C contents. Fertilizer practices were the principal factor influencing rhizosphere soil cbbL-carrying bacterial communities. These results showed that rhizosphere soil autotrophic bacterial communities were significantly changed under conditions of different long-term fertilization practices Therefore, increasing rhizosphere soil autotrophic bacteria community with crop residue and organic manure practices was found to be beneficial for management of double rice ecosystems in southern China.

Preliminary Study of the Ecological Impact of Forest Fires in G. Massigit, G. Gede-Pangrango National Park, West Java

  • Abdulhadi, Rochadi;Adhikerana, A.S.;Ubaidillah, R.;Suharna, N.
    • The Korean Journal of Ecology
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    • 제23권2호
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    • pp.125-129
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    • 2000
  • Gunung Gede Pangrango National Park is one of the Long-term Ecological Research Site in Indonesia. In the late 1997, the fires have burnt and destroyed nearly 300 ha forest in this park. and G. Masigit was the largest burnt area (250 ha) of nine locations of hot spot recognized. Undergrowth vegetation got the most severe impacts. Almost undergrowth vegetation in various location were totally burnt. However, within three months following burning new seedlings such as Omalanthus populneus, Macaranga, Trema orientalis and Eupatorium appeared in the forest floor- The number of mycoflora recorded in burnt forest was interestingly increased in post forest fires site. Forest fires in G. Masigit had also affected the wild life population and diversity. For example, the number of bird species and the number of soil insects in burnt forest was significantly reduced. The forest fires had also great impact on soil. such as on soil organic contents, bulk density, colour, consistency, permeability and the activity of soil microorganisms.

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백운산 지역에서 벌채지내 운재로의 회복에 관한 연구 (A Study on the Restoration on the Strip Roads Mt. Baekun Area)

  • 박재현
    • 한국환경복원기술학회지
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    • 제10권2호
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    • pp.34-43
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    • 2007
  • To investigate the restoration procedure on soil physical properties and vegetation at the surface of strip road affected by timber harvesting operation. This study was carried out at strip roads constructed between 1989 and 1994 in Mt. Baekun, Kwangyang, Chollanam-Do. Soil hardness of the surface layer was improved with change of time after strip road construction, but that of 7.6~15 cm depth from the surface was not improved. According to linear regression analysis, it was estimated 16.6 years in 0~7.5 cm and 16.9 years in 7.6~15 cm soil depth to be restored to natural forest lands. The amount of surface soil erosion was 0.045$m^3$/km/yr on strip roads constructed in 1989 and 1990, and road constructed in 1994 showed the highest value (4.5$m^3$/km/yr). Vegetation coverage rates of road surface were 96.7% in strip roads constructed in 1990. Those of cutslope and fillslope were highest in roads constructed in 1990. The results indicated that strip roads were restored with change of time after road construction.

Effect of Winter Crop Cultivation on Soil Organic Carbon and Physico-chemical Properties Under Different Rice-forage Cropping Systems in Paddy Soil

  • Yun, Sun-Gang;Lee, Chang-Hoon;Ko, Byong-Gu;Park, Seong-Jin;Kim, Myung-Sook;Kim, Ki-Yong
    • 한국토양비료학회지
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    • 제49권4호
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    • pp.335-340
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    • 2016
  • Soil organic carbon plays an important role on soil physico-chemical properties and crop yields in paddy soil. However, there is little information on the soil organic carbon under different forage cultivation during winter season in rice paddy. In this study, we investigated the soil organic carbon and physico-chemical properties in 87 fields of paddy soil cultivated with Barley, rye, and Italian ryegrass (IRG) as animal feedstock during winter season. Organic carbon was 12.9, 14.3, and $16.9g\;C\;kg^{-1}$ in soil with barley, rye, and IRG cultivation, respectively. Among rice-forage cultivation systems, the rice+IRG cropping system was 19.5% higher than in the mono-rice cultivation. Bulk density ranged from 1.17 to $1.28g\;cm^{-3}$ irrespective of cropping systems, and had strongly negative correlation with the soil organic carbon in the rice+IRG cropping system. Carbon storage in rice+IRG cropping systems was average $29.6Mg\;ha^{-1}$ at 15 cm of soil depth, which was 20.4 and 10.3% higher than those of barley and rye cultivation. Increasing carbon storage in paddy soil contributed to the fertility for following rice cultivation. This results indicated that IRG cultivation during winter season could be an alternative and promising way to enhance soil organic carbon content and fertility of paddy soil.