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| Titel |
Depth distribution of preferential flow patterns in a sandy loam soil as affected by tillage |
| VerfasserIn |
C. T. Petersen, S. Hansen, H. E. Jensen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 1, no. 4 ; Nr. 1, no. 4, S.769-776 |
| Datensatznummer |
250000232
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| Publikation (Nr.) |
 copernicus.org/hess-1-769-1997.pdf |
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| Zusammenfassung |
Dye-tracer studies using the anionic dye Brilliant
Blue FCF were conducted on a structured sandy loam soil (Typic Agrudalf). 25 mm of dye solution was applied
to the surface of 11 1.6 x 1.6 m field plots, some of which had been subjected to conventional
seed bed preparation (harrowing) while others had been rotovated to either 5 or 15 cm depth
before sowing. The soil was excavated to about 160 cm depth one or two days after dye application.
Flow patterns and structural features appearing on vertical or horizontal cross sections
were examined and photographed. The flow patterns were digitized, and depth functions
for the number of activated flow pathways and the degree of dye coverage were calculated.
Dye was found below 100 cm depth on 26 out of 33
vertical cross sections made in conventionally tilled plots showing that preferential flow was a prevailing
phenomenon. The depth-averaged number of stained flow pathways in the 25-100 cm layer
was significantly smaller in a plot rotovated to 5 cm depth than in a conventionally tilled plot,
both under relatively dry initial soil conditions and when the entire soil profiles were initially
at field capacity. There were no examples of dye penetration below 25 cm depth one month after deep
rotovation. Distinct horizontal structures in flow patterns appearing at 20-40 cm depth
coupled with changes in flow domains indicated soil layering with abrupt changes in soil structure
and hydraulic properties. |
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