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通过土柱淋溶试验 ,研究了用时域反射仪 (TDR)测定土壤溶质运移过程中的影响因素。结果表明 ,TDR测定溶质的浓度存在着上、下限。用Ca (NO3 ) 2 作示踪剂时 ,TDR测定的下限为 40mg/L ;温度是另一主要的影响因素 ,随着温度的升高 ,TDR的电阻值下降 ;不同流速和不同浓度均对溶质运移的平衡时间有影响。由于重力势的作用 ,土柱上、下层之间达到平衡的时间也有显著的差异。实验中的淋洗平衡液不宜用蒸馏水或去离子水 ,用自来水可提高土壤溶液电导率的基线
Soil column leaching test was used to study the influence factors of soil solute transport by time-domain reflectometer (TDR). The results show that the TDR determination of solute concentration of the upper and lower limits. With Ca (NO3) 2 as a tracer, the lower limit of determination of TDR was 40mg / L; temperature was another major factor, with the increase of temperature, TDR resistance decreased; different flow rates and different concentrations were The balance of solute transport has an impact. Due to the effect of the gravitational potential, there are also significant differences in the timing of reaching equilibrium between the upper and lower soil columns. In the experiment, the eluent should not use distilled water or deionized water. The tap water can improve the conductivity of soil solution