[Preferential flow and its effect on solute migration in soil].
The characteristics of soil preferential flow and the preferential migrate in soil for non-absorptive bromide and nitrate ions were studied. With undisturbed and packed soil columns, the results showed that soil preferential flow was characterized with preferential breakthrough, non-symmetric breakthrough curve, lateral infiltration, tailing and so on. The preferential breakthrough for Br- was 24 hours after it was applied, and the leachate volume was only 0.04 times as-much as the pore volumes. The preferential flow for Br- accounted for 26% of total flux in the undisturbed soil columns. But the accumulative leachate mass for Br- resulted from the preferential flow were 86.7% of total accumulative leachate mass, showing that the soil preferential flow accounted for relative small ratio of the flux, but caused relative much more solute transference. NO3- was moved down rapidly by preferential flow at only one time as large as pore volumes, and got 11% of the applied amount, respectively. As a result of the preferential flow, the lateral infiltration flow enabled Br- and NO3- rapidly distribute and diffuse into the deeper soil.
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Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016. Yuwenni@sina.com
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Ying
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D001966:Bromine / Q000737:chemistry*; D009566:Nitrates / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D014867:Water
D009566:Nitrates; D012987:Soil; D014867:Water; D001966:Bromine