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| Titel |
How effective are soil and water conservation techniques in reducing annual plot runoff and soil loss? A pan-European and Mediterranean review and analysis. |
| VerfasserIn |
W. Maetens, J. Poesen, M. Vanmaercke |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250058594
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| Zusammenfassung |
| While a substantial number of experimental studies on the effectiveness of soil and water
conservation techniques (SWCTs) in reducing annual runoff (Ra) and annual soil loss (SLa)
at plot scales in Europe and the Mediterranean exists, a comprehensive overview and analysis
of plot Ra and SLa data is lacking. Therefore, the objective of this study is to analyse the
effectiveness of SWCT in reducing Ra and SLa in Europe and the Mediterranean, as well as
to explore the factors that determine SWCT effectiveness. In the framework of the FP6
project DESIRE (http://www.desire-project.eu), a comprehensive plot database was compiled
based on an extensive literature review covering 101 reports and publications. The database
contains Ra and SLa data measured on runoff plots, where various SWCTs were
tested in the Euro-Mediterranean region. The total database contains 353 plots,
corresponding to 2 093 plot-years from 103 plot measuring stations throughout Europe and
the Mediterranean. For 224 of these plots (corresponding to 1 567 plot-years), Ra
and/or SLa from a paired plot with the same dimensions, land use and measuring
period, but without the application SWCT was available, allowing to assess the
effectiveness of the applied SWCTs. Documented SWCTs include cover crops,
mulching, grass buffer strips, strip cropping, exclosure, no-tillage, reduced tillage,
contour tillage, deep tillage, drainage, soil amendment, terraces, contour bunds and
geotextiles.
Analyses of the database shows that there are clear differences in effectiveness in
reducing Ra and SLa between different SWCTs. Techniques related to crop and vegetation
management like mulching (median reduction of Ra to 32% and SLa to 23% of the
corresponding values measured on the plot without SWCT) and cover crops (36% for Ra and
14% for SLa) are more effective than soil management techniques like no-tillage
(85% for Ra and 57% for SLa) or reduced tillage (90% for Ra and 68% for SLa).
While these techniques are commonly referred to as soil and water conservation
techniques, these figures also show that they are less effective in reducing Ra than in
reducing SLa. Furthermore, analysis of time series of multiple consecutive years of Ra
and/or SLa measurements show that no-tillage and conservation tillage become
less effective in reducing Ra over time, but no such effect is observed for annual
SLa.
This has important consequences for the use of these techniques in e.g. drought-prone
areas where water conservation is a key issue and also needs to be considered in the
assessment of the effects of SWCTs at larger scales. Furthermore, effectiveness of
different SWCTs is found to be highly variable and requires further analysis of
the factors controlling SWCT effectiveness. All SWCTs show a more consistent
and effective reduction of both Ra and SLa with increasing magnitude of Ra and
SLa, which is attributed to the reduced influence of measurement uncertainties
with increasing Ra and SLa. No general relations between SWCT effectiveness in
reducing Ra and SLa and plot slope length, slope gradient or annual precipitation were
found.
Keywords: soil and water conservation techniques, runoff reduction, soil loss reduction,
plot scale, Europe and the Mediterranean |
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