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| Titel |
Statistical and Multifractal Evaluation of Soil Compaction in a Vineyard |
| VerfasserIn |
M. Marinho, J. R. Raposo, J. M. Miras Avalos, A. Paz González |
| 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 |
250061662
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| Zusammenfassung |
| One of the detrimental effects caused by agricultural machines is soil compaction, which can
be defined by an increase in soil bulk density. Soil compaction often has a negative
impact on plant growth, since it reduces the macroporosity and soil permeability and
increases resistance to penetration. Our research explored the effect of the agricultural
machinery on soil when trafficking through a vineyard at a small spatial scale, based on
the evaluation of the soil compaction status. The objectives of this study were: i)
to quantify soil bulk density along transects following wine row, wheel track and
outside track, and, ii) to characterize the variability of the bulk density along these
transects using multifractal analysis. The field work was conducted at the experimental
farm of EVEGA (Viticulture and Enology Centre of Galicia) located in Ponte San
Clodio, Leiro, Orense, Spain. Three parallel transects were marked on positions with
contrasting machine traffic effects, i.e. vine row, wheel-track and outside-track.
Undisturbed samples were collected in 16 points of each transect, spaced 0.50 m
apart, for bulk density determination using the cylinder method. Samples were taken
in autumn 2011, after grape harvest. Since soil between vine rows was tilled and
homogenized beginning spring 2011, cumulative effects of traffic during the vine
growth period could be evaluated. The distribution patterns of soil bulk density
were characterized by multifractal analysis carried out by the method of moments.
Multifractality was assessed by several indexes derived from the mass exponent, Ïq, the
generalized dimension, Dq, and the singularity spectrum, f(α), curves. Mean soil bulk
density values determined for vine row, outside-track and wheel-track transects were
1.212 kg dm-3, 1.259 kg dm-3and 1.582 kg dm-3, respectively. The respective
coefficients of variation (CV) for these three transects were 7.76%, 4.82% and
2.03%. Therefore mean bulk density under wheel-track was 30.5% higher than
along the vine row. Vine row and outside-track positions showed not significant
differences between means. The bulk density of the wheel-track transect also showed the
lowest CV. The multifractal spectra of the three transects were asymmetric curves,
rather short toward the left and much longer toward the right. The width of the right
deviating shaped multifractal spectra was ranked as: wine row > outside-track -
wheel-track. Entropy dimension, D1, was 0.998, 0.992 and 0.992 for vine row,
outside-track and track transects, respectively. These results show different patterns of
variability of bulk density for parallel transects. They also suggest that multifractal
parameters may be useful in assessing the variability of other soil properties such as soil
particle density, soil porosity or soil water content, at different spatial scales as
well.
Acknowledgments. This work was funded in part by Spanish Ministry of Science and
Innovation (MICINN) in the frame of project CGL2009-13700-C02. Financial
support from CAPES/GOV., Brazil, is also acknowledged by Prof. M. Marinho. |
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