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    业绩一览 > 高精度杠杆式蒸渗仪 > 国外研究现状

    国外研究现状

    国外研究现状

    <1> Comparison of deep seepage estimations of a virtual with a real lysimeterby means of TDR-measurements

      U.Schindler and L.Mueller

      Centrefor AgriculturalLandscape and LandUse Research(ZALF), Institute of Soil Landscape Research,Eberswalder Str. 84,

      D-15374 Müncheberg,Germany Received February 4, 2004; accepted June 15, 2004

      通过TDR-measurements手段比较深度防渗虚拟预测体系和蒸渗仪之间的差别

      摘要:对虚拟蒸渗仪概念进行测试并用于实际蒸渗仪的比较,结果发现虚拟蒸渗仪能适用于沙质土壤动态有效深层渗透的研究中。排出量的实际测试值与计算结果相一致。其先决条件是精确的含水量和高强度测量。其中高强度测试要求在零通量面和一个错误自由水平衡的校准时期内的高时间分辨率。校准程序导致一个只能执行测量水含量的深度渗透计算的有效非饱和水力传导功能。假设在沙质土壤中充足的单位梯度生产。计算结果是以错误水含量测试和错误水平衡线性敏感度呈指数型变化的。然而,一个不正确水含量只生产单一的不正确深层渗透值,而水平衡总量错误。因此,水的质量平衡估计是至关重要的。

      <2>. Die Gras – Referenzverdunstung:Berechnungsergebnisse in Abhangigkeit von Messgeraten und Messintervall

      参考草地蒸发:通过Messgeraten和测试的计算结果

      摘要:联合国粮农组织(粮食农业组织)预计农作物的蒸散量的普遍基础是参考草地每日天气蒸散量计算数据。彭曼一蒙特斯的蒸散量方程已由ASEC(美国土木工程学会)标准化。短时间的间隔计算参数已经给出?;赪agna(施蒂里亚州,奥地利)研究站的计算数据,草地参考的蒸发量使用不同时段的气象数据,对比通过可称重单片蒸渗仪精确测量的草地蒸散量。结果表明,参考草地蒸散量计算使用了粮农组织或学会方程,其不确定性可能比较低的。区域推广的应用使用了每日天气数据可能会使参照蒸散量足够的精确。为验证土壤水分模型和蒸渗仪数据的详细评价,建议通过气象参数和ASEC方程的测量时间间隔不要超过10分钟。

      <3> 摘要:Pesticide leaching from soil has been shown to decrease with increasing time from application to irrigation. It is hypothesized that the availability of compounds for leaching decreases due to diffusion and sorption inside soil aggregates. Previous work showed that pesticide sorption inside soil aggregates increases significantly during the first days after application. The study presented here tested if diffusion into aggregates could explain the leaching of four aged pesticides from manually irrigated soil cores. Azoxystrobin, chlorotoluron, cyanazine, and bentazone were applied to 30 undisturbed cores (25 cm long, 23.7 cm diameter) from a clay loam soil. The soil cores were irrigated 1, 3, 7, 14, and 28 days after application. Leachate was collected and analyzed. The amount of pesticide found in leachate decreased rapidly with time from application. Pesticide losses in leachate declined 2.5 27 times faster than total residues in soil. The decline was 4 5 times faster for the more strongly sorbed pesticides (azoxystrobin, chlorotoluron, and cyanazine) than for bentazone. In previous work, we derived a model to describe sorption and diffusion of the pesticides in small aggregates from the same soil. The diffusion model was used here to describe sorption inside the large aggregates in the soil cores and extended to describe pesticide leaching by interaggregate flow. The model showed a significant decline in leaching with time from application, which supports the theory that diffusion-limited sorption in aggregates influences the availability for pesticide leaching, although it does not exclude alternative explanations for this decline. The model well described the decline in leaching for three out of four pesticides. The interaggregate transport model could, however, not account for the amount of preferential flow in the cores and underestimated the leaching of bentazone.

      摘要:随着从耕种到灌溉时间的延续,农药从土壤中的渗出量逐渐减少。假设内部土壤团的分散和吸附,可用的渗出化合物减少。以往的工作表明,农药第一天喷洒后,土壤内部的吸附总量显著增加。目前的研究测试表明,如果分散进入土壤团内部,则可以解释通过手动灌溉土壤内核的四阶段农药渗出情况。嘧菌酯,绿麦隆,氰,苯达松适用于粘土土壤中的30个不受干扰内核(长为25厘米,直径为23.7厘米)。喷洒后的1、3、7、14和28天对土壤核进行灌溉,对渗滤液进行收集和分析。喷洒撒后随着时间的推移,渗滤液中的农药总量迅速下降。渗滤液的农药损失量下降2.5,比土壤中总残留量快27倍。更强吸附力的农药(嘧菌酯,绿麦隆,和氰)比苯达松的下降速度快4到5倍。通过前期工作,我们得到一种模型来描述农药在同一土壤的小土团中的吸附和扩散。这个扩散模型用在这里描述土壤内核中大土团的吸附,并扩展到描述土团流动中的农药渗出。该模型随着时间的推移有显著的下降趋势,虽然这一下降趋势并不排除其他可能的解释,但是它支持在土团流动中农药渗出的有限扩散吸附这一理论。这个模型很好的描述了75%的农药渗出下降趋势。然后,土团运输模型不适用于低流量土核和低渗透量苯达松的情况。

      <4> Die Bedeutung der Ergebnisse der Untersuchungen an der Forschungsstation Wagna für die ackerbauliche Praxis im Grundwassergebiet des Murtales von Graz bis Bad Radkersburg

      摘要:农业对地下水系统的影响与土地利用强度和粮食产物密切相关。因为相关农药和化肥用量的增加导致欧洲大多数低地都存在地下水质量问题。奥地利南部穆尔河的含水层是一个典型的河谷含水层,是由第四纪砾石和沙子建筑而成。上个世纪80年代,由于改变了农业耕种方式和化肥农药的用量,使得地下水的杂志含量超过了法定标准。管理,农民,水务工程和科学组织之间的合作,达成了减少农业生产对地下水影响的协议。

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