Root tensile strength is an important factor controlling the performance of bio-slope stabilization works. Due to evapotranspiration and climate factors, the root moisture content and its suction can vary seasonally i...Root tensile strength is an important factor controlling the performance of bio-slope stabilization works. Due to evapotranspiration and climate factors, the root moisture content and its suction can vary seasonally in practice and may not equal soil suction. The influences of suction and root moisture contents were investigated on Chrysopogon zizanioides(vetiver grass) root tensile strength. The root specimens were equilibrated with moist air in different suction conditions(0, 10, 20, and 50 kPa), prior to root tension tests. The root-water characteristic curve or relationship between root moisture and suction, was determined. The increase in suction resulted in decreased tensile strengths of the grass roots, particularly those with diameter of about 0.2 mm, which constituted 50.7% of all roots. For 1 mm roots, the tensile strength appeared to be unaffected by suction increase. The average root tensile strengths were used to estimate the root cohesion in slope stability analysis to find variation of safety factors of a bioengineered slope in different suction conditions. The analysis showed that the critical condition of slope with the lowest factor of safety would happen when the soil suction was zero and the root suction was high. Such condition may occur during a heavy rain period after a prolonged drought.展开更多
This study aims to investigate the capacity of <i>Chrysopogon</i> <i>nigritanus</i> to accumulate As from contaminated soils<i>.</i><b> </b>The experiment was conducted ...This study aims to investigate the capacity of <i>Chrysopogon</i> <i>nigritanus</i> to accumulate As from contaminated soils<i>.</i><b> </b>The experiment was conducted in a greenhouse. <i>C.</i> <i>nigritanus</i> was subjected to uncontaminated soil and As contaminated soil (50 mg/kg, 100 mg/kg and 150 mg/kg of As), for 180 days. Plant growth and biomass produced, concentration of As in soil and plant, bioaccumulation and transfer factors, as the location of As in tissues and cells of the plant have been determined. Plant growth decreased significantly with increasing of soil As concentration. <i>C.</i> <i>nigritanus</i> accumulated more As in roots biomass. The highest bioaccumulation factor values were found in contaminated soil at 50 mg As/kg (As 50), then contaminated soil at 100 mg As/kg (As 100) and contaminated soil at 150 mg As/kg (As 150). As was essentially fixed to the intracellular compartment of the roots, stems and leaves. In roots tissues, As was mainly retained in the rhizodermis and the pericycle. While in stems tissues, As was preferentially accumulated in the conductive bundles. In the leaves, the final destination of As was epidermis tissues.展开更多
以相对地上干重、相对地下干重、叶片枯黄率、叶片颜色、坪用质量为评价指标,在245 mmol/L Na Cl胁迫下,利用水培法对64份竹节草(Chrysopogon aciculatus)种质资源进行耐盐性初步评价。结果表明,各品系之间存在显著(p〈0.05)或极显...以相对地上干重、相对地下干重、叶片枯黄率、叶片颜色、坪用质量为评价指标,在245 mmol/L Na Cl胁迫下,利用水培法对64份竹节草(Chrysopogon aciculatus)种质资源进行耐盐性初步评价。结果表明,各品系之间存在显著(p〈0.05)或极显著差异(p〈0.01),各指标的变异系数范围为20.64%(相对地上部干重)-43.40%(相对坪用质量)。相关性分析结果表明,参数指标间存在显著相关性(p〈0.05)或极显著相关性(p〈0.01),相关系数最高达到0.912。利用5个指标对64份品系进行聚类分析,在欧式距离18.0处,分为敏盐型、中间型、耐盐型三大类。展开更多
基金the financial supports from the Chaipattana FoundationKasetsart University Research and Development Institute(KURDI)the scholarship for his PhD studies provided by the Faculty of Engineering,Kasetsart University
文摘Root tensile strength is an important factor controlling the performance of bio-slope stabilization works. Due to evapotranspiration and climate factors, the root moisture content and its suction can vary seasonally in practice and may not equal soil suction. The influences of suction and root moisture contents were investigated on Chrysopogon zizanioides(vetiver grass) root tensile strength. The root specimens were equilibrated with moist air in different suction conditions(0, 10, 20, and 50 kPa), prior to root tension tests. The root-water characteristic curve or relationship between root moisture and suction, was determined. The increase in suction resulted in decreased tensile strengths of the grass roots, particularly those with diameter of about 0.2 mm, which constituted 50.7% of all roots. For 1 mm roots, the tensile strength appeared to be unaffected by suction increase. The average root tensile strengths were used to estimate the root cohesion in slope stability analysis to find variation of safety factors of a bioengineered slope in different suction conditions. The analysis showed that the critical condition of slope with the lowest factor of safety would happen when the soil suction was zero and the root suction was high. Such condition may occur during a heavy rain period after a prolonged drought.
文摘This study aims to investigate the capacity of <i>Chrysopogon</i> <i>nigritanus</i> to accumulate As from contaminated soils<i>.</i><b> </b>The experiment was conducted in a greenhouse. <i>C.</i> <i>nigritanus</i> was subjected to uncontaminated soil and As contaminated soil (50 mg/kg, 100 mg/kg and 150 mg/kg of As), for 180 days. Plant growth and biomass produced, concentration of As in soil and plant, bioaccumulation and transfer factors, as the location of As in tissues and cells of the plant have been determined. Plant growth decreased significantly with increasing of soil As concentration. <i>C.</i> <i>nigritanus</i> accumulated more As in roots biomass. The highest bioaccumulation factor values were found in contaminated soil at 50 mg As/kg (As 50), then contaminated soil at 100 mg As/kg (As 100) and contaminated soil at 150 mg As/kg (As 150). As was essentially fixed to the intracellular compartment of the roots, stems and leaves. In roots tissues, As was mainly retained in the rhizodermis and the pericycle. While in stems tissues, As was preferentially accumulated in the conductive bundles. In the leaves, the final destination of As was epidermis tissues.
文摘以相对地上干重、相对地下干重、叶片枯黄率、叶片颜色、坪用质量为评价指标,在245 mmol/L Na Cl胁迫下,利用水培法对64份竹节草(Chrysopogon aciculatus)种质资源进行耐盐性初步评价。结果表明,各品系之间存在显著(p〈0.05)或极显著差异(p〈0.01),各指标的变异系数范围为20.64%(相对地上部干重)-43.40%(相对坪用质量)。相关性分析结果表明,参数指标间存在显著相关性(p〈0.05)或极显著相关性(p〈0.01),相关系数最高达到0.912。利用5个指标对64份品系进行聚类分析,在欧式距离18.0处,分为敏盐型、中间型、耐盐型三大类。
基金Project(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China